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Diffstat (limited to 'numpy/lib/arraypad.py')
| -rw-r--r-- | numpy/lib/arraypad.py | 1394 |
1 files changed, 477 insertions, 917 deletions
diff --git a/numpy/lib/arraypad.py b/numpy/lib/arraypad.py index 66f21bfca..570f86969 100644 --- a/numpy/lib/arraypad.py +++ b/numpy/lib/arraypad.py @@ -16,50 +16,67 @@ __all__ = ['pad'] # Private utility functions. -def _arange_ndarray(arr, shape, axis, reverse=False): +def _linear_ramp(ndim, axis, start, stop, size, reverse=False): """ - Create an ndarray of `shape` with increments along specified `axis` + Create a linear ramp of `size` in `axis` with `ndim`. + + This algorithm behaves like a vectorized version of `numpy.linspace`. + The resulting linear ramp is broadcastable to any array that matches the + ramp in `shape[axis]` and `ndim`. Parameters ---------- - arr : ndarray - Input array of arbitrary shape. - shape : tuple of ints - Shape of desired array. Should be equivalent to `arr.shape` except - `shape[axis]` which may have any positive value. + ndim : int + Number of dimensions of the resulting array. All dimensions except + the one specified by `axis` will have the size 1. axis : int - Axis to increment along. + The dimension that contains the linear ramp of `size`. + start : int or ndarray + The starting value(s) of the linear ramp. If given as an array, its + size must match `size`. + stop : int or ndarray + The stop value(s) (not included!) of the linear ramp. If given as an + array, its size must match `size`. + size : int + The number of elements in the linear ramp. If this argument is 0 the + dimensions of `ramp` will all be of length 1 except for the one given + by `axis` which will be 0. reverse : bool - If False, increment in a positive fashion from 1 to `shape[axis]`, - inclusive. If True, the bounds are the same but the order reversed. + If False, increment in a positive fashion, otherwise decrement. Returns ------- - padarr : ndarray - Output array sized to pad `arr` along `axis`, with linear range from - 1 to `shape[axis]` along specified `axis`. - - Notes - ----- - The range is deliberately 1-indexed for this specific use case. Think of - this algorithm as broadcasting `np.arange` to a single `axis` of an - arbitrarily shaped ndarray. + ramp : ndarray + Output array of dtype np.float64 that in- or decrements along the given + `axis`. + Examples + -------- + >>> _linear_ramp(ndim=2, axis=0, start=np.arange(3), stop=10, size=2) + array([[0. , 1. , 2. ], + [5. , 5.5, 6. ]]) + >>> _linear_ramp(ndim=3, axis=0, start=2, stop=0, size=0) + array([], shape=(0, 1, 1), dtype=float64) """ - initshape = tuple(1 if i != axis else shape[axis] - for (i, x) in enumerate(arr.shape)) - if not reverse: - padarr = np.arange(1, shape[axis] + 1) - else: - padarr = np.arange(shape[axis], 0, -1) - padarr = padarr.reshape(initshape) - for i, dim in enumerate(shape): - if padarr.shape[i] != dim: - padarr = padarr.repeat(dim, axis=i) - return padarr + # Create initial ramp + ramp = np.arange(size, dtype=np.float64) + if reverse: + ramp = ramp[::-1] + + # Make sure, that ramp is broadcastable + init_shape = (1,) * axis + (size,) + (1,) * (ndim - axis - 1) + ramp = ramp.reshape(init_shape) + + if size != 0: + # And scale to given start and stop values + gain = (stop - start) / float(size) + ramp = ramp * gain + ramp += start + return ramp -def _round_ifneeded(arr, dtype): + +def _round_if_needed(arr, dtype): """ Rounds arr inplace if destination dtype is integer. @@ -69,821 +86,418 @@ def _round_ifneeded(arr, dtype): Input array. dtype : dtype The dtype of the destination array. - """ if np.issubdtype(dtype, np.integer): arr.round(out=arr) -def _slice_at_axis(shape, sl, axis): - """ - Construct a slice tuple the length of shape, with sl at the specified axis - """ - slice_tup = (slice(None),) - return slice_tup * axis + (sl,) + slice_tup * (len(shape) - axis - 1) - - -def _slice_first(shape, n, axis): - """ Construct a slice tuple to take the first n elements along axis """ - return _slice_at_axis(shape, slice(0, n), axis=axis) - - -def _slice_last(shape, n, axis): - """ Construct a slice tuple to take the last n elements along axis """ - dim = shape[axis] # doing this explicitly makes n=0 work - return _slice_at_axis(shape, slice(dim - n, dim), axis=axis) - - -def _do_prepend(arr, pad_chunk, axis): - return np.concatenate( - (pad_chunk.astype(arr.dtype, copy=False), arr), axis=axis) - - -def _do_append(arr, pad_chunk, axis): - return np.concatenate( - (arr, pad_chunk.astype(arr.dtype, copy=False)), axis=axis) - - -def _prepend_const(arr, pad_amt, val, axis=-1): +def _slice_at_axis(sl, axis): """ - Prepend constant `val` along `axis` of `arr`. + Construct tuple of slices to slice an array in the given dimension. Parameters ---------- - arr : ndarray - Input array of arbitrary shape. - pad_amt : int - Amount of padding to prepend. - val : scalar - Constant value to use. For best results should be of type `arr.dtype`; - if not `arr.dtype` will be cast to `arr.dtype`. + sl : slice + The slice for the given dimension. axis : int - Axis along which to pad `arr`. + The axis to which `sl` is applied. All other dimensions are left + "unsliced". Returns ------- - padarr : ndarray - Output array, with `pad_amt` constant `val` prepended along `axis`. + sl : tuple of slices + A tuple with slices matching `shape` in length. + Examples + -------- + >>> _slice_at_axis(slice(None, 3, -1), 1) + (slice(None, None, None), slice(None, 3, -1), (...,)) """ - if pad_amt == 0: - return arr - padshape = tuple(x if i != axis else pad_amt - for (i, x) in enumerate(arr.shape)) - return _do_prepend(arr, np.full(padshape, val, dtype=arr.dtype), axis) + return (slice(None),) * axis + (sl,) + (...,) -def _append_const(arr, pad_amt, val, axis=-1): +def _view_roi(array, original_area_slice, axis): """ - Append constant `val` along `axis` of `arr`. + Get a view of the current region of interest during iterative padding. - Parameters - ---------- - arr : ndarray - Input array of arbitrary shape. - pad_amt : int - Amount of padding to append. - val : scalar - Constant value to use. For best results should be of type `arr.dtype`; - if not `arr.dtype` will be cast to `arr.dtype`. - axis : int - Axis along which to pad `arr`. - - Returns - ------- - padarr : ndarray - Output array, with `pad_amt` constant `val` appended along `axis`. - - """ - if pad_amt == 0: - return arr - padshape = tuple(x if i != axis else pad_amt - for (i, x) in enumerate(arr.shape)) - return _do_append(arr, np.full(padshape, val, dtype=arr.dtype), axis) - - - -def _prepend_edge(arr, pad_amt, axis=-1): - """ - Prepend `pad_amt` to `arr` along `axis` by extending edge values. + When padding multiple dimensions iteratively corner values are + unnecessarily overwritten multiple times. This function reduces the + working area for the first dimensions so that corners are excluded. Parameters ---------- - arr : ndarray - Input array of arbitrary shape. - pad_amt : int - Amount of padding to prepend. + array : ndarray + The array with the region of interest. + original_area_slice : tuple of slices + Denotes the area with original values of the unpadded array. axis : int - Axis along which to pad `arr`. + The currently padded dimension assuming that `axis` is padded before + `axis` + 1. Returns ------- - padarr : ndarray - Output array, extended by `pad_amt` edge values appended along `axis`. - + roi : ndarray + The region of interest of the original `array`. """ - if pad_amt == 0: - return arr + axis += 1 + sl = (slice(None),) * axis + original_area_slice[axis:] + return array[sl] - edge_slice = _slice_first(arr.shape, 1, axis=axis) - edge_arr = arr[edge_slice] - return _do_prepend(arr, edge_arr.repeat(pad_amt, axis=axis), axis) - -def _append_edge(arr, pad_amt, axis=-1): +def _pad_simple(array, pad_width, fill_value=None): """ - Append `pad_amt` to `arr` along `axis` by extending edge values. + Pad array on all sides with either a single value or undefined values. Parameters ---------- - arr : ndarray - Input array of arbitrary shape. - pad_amt : int - Amount of padding to append. - axis : int - Axis along which to pad `arr`. + array : ndarray + Array to grow. + pad_width : sequence of tuple[int, int] + Pad width on both sides for each dimension in `arr`. + fill_value : scalar, optional + If provided the padded area is filled with this value, otherwise + the pad area left undefined. Returns ------- - padarr : ndarray - Output array, extended by `pad_amt` edge values prepended along - `axis`. - + padded : ndarray + The padded array with the same dtype as`array`. Its order will default + to C-style if `array` is not F-contiguous. + original_area_slice : tuple + A tuple of slices pointing to the area of the original array. """ - if pad_amt == 0: - return arr - - edge_slice = _slice_last(arr.shape, 1, axis=axis) - edge_arr = arr[edge_slice] - return _do_append(arr, edge_arr.repeat(pad_amt, axis=axis), axis) + # Allocate grown array + new_shape = tuple( + left + size + right + for size, (left, right) in zip(array.shape, pad_width) + ) + order = 'F' if array.flags.fnc else 'C' # Fortran and not also C-order + padded = np.empty(new_shape, dtype=array.dtype, order=order) + if fill_value is not None: + padded.fill(fill_value) -def _prepend_ramp(arr, pad_amt, end, axis=-1): - """ - Prepend linear ramp along `axis`. + # Copy old array into correct space + original_area_slice = tuple( + slice(left, left + size) + for size, (left, right) in zip(array.shape, pad_width) + ) + padded[original_area_slice] = array - Parameters - ---------- - arr : ndarray - Input array of arbitrary shape. - pad_amt : int - Amount of padding to prepend. - end : scalar - Constal value to use. For best results should be of type `arr.dtype`; - if not `arr.dtype` will be cast to `arr.dtype`. - axis : int - Axis along which to pad `arr`. + return padded, original_area_slice - Returns - ------- - padarr : ndarray - Output array, with `pad_amt` values prepended along `axis`. The - prepended region ramps linearly from the edge value to `end`. +def _set_pad_area(padded, axis, width_pair, value_pair): """ - if pad_amt == 0: - return arr - - # Generate shape for final concatenated array - padshape = tuple(x if i != axis else pad_amt - for (i, x) in enumerate(arr.shape)) - - # Generate an n-dimensional array incrementing along `axis` - ramp_arr = _arange_ndarray(arr, padshape, axis, - reverse=True).astype(np.float64) - - # Appropriate slicing to extract n-dimensional edge along `axis` - edge_slice = _slice_first(arr.shape, 1, axis=axis) - - # Extract edge, and extend along `axis` - edge_pad = arr[edge_slice].repeat(pad_amt, axis) - - # Linear ramp - slope = (end - edge_pad) / float(pad_amt) - ramp_arr = ramp_arr * slope - ramp_arr += edge_pad - _round_ifneeded(ramp_arr, arr.dtype) - - # Ramp values will most likely be float, cast them to the same type as arr - return _do_prepend(arr, ramp_arr, axis) - - -def _append_ramp(arr, pad_amt, end, axis=-1): - """ - Append linear ramp along `axis`. + Set empty-padded area in given dimension. Parameters ---------- - arr : ndarray - Input array of arbitrary shape. - pad_amt : int - Amount of padding to append. - end : scalar - Constal value to use. For best results should be of type `arr.dtype`; - if not `arr.dtype` will be cast to `arr.dtype`. + padded : ndarray + Array with the pad area which is modified inplace. axis : int - Axis along which to pad `arr`. - - Returns - ------- - padarr : ndarray - Output array, with `pad_amt` values appended along `axis`. The - appended region ramps linearly from the edge value to `end`. - + Dimension with the pad area to set. + width_pair : (int, int) + Pair of widths that mark the pad area on both sides in the given + dimension. + value_pair : tuple of scalars or ndarrays + Values inserted into the pad area on each side. It must match or be + broadcastable to the shape of `arr`. """ - if pad_amt == 0: - return arr - - # Generate shape for final concatenated array - padshape = tuple(x if i != axis else pad_amt - for (i, x) in enumerate(arr.shape)) + left_slice = _slice_at_axis(slice(None, width_pair[0]), axis) + padded[left_slice] = value_pair[0] - # Generate an n-dimensional array incrementing along `axis` - ramp_arr = _arange_ndarray(arr, padshape, axis, - reverse=False).astype(np.float64) + right_slice = _slice_at_axis( + slice(padded.shape[axis] - width_pair[1], None), axis) + padded[right_slice] = value_pair[1] - # Slice a chunk from the edge to calculate stats on - edge_slice = _slice_last(arr.shape, 1, axis=axis) - # Extract edge, and extend along `axis` - edge_pad = arr[edge_slice].repeat(pad_amt, axis) - - # Linear ramp - slope = (end - edge_pad) / float(pad_amt) - ramp_arr = ramp_arr * slope - ramp_arr += edge_pad - _round_ifneeded(ramp_arr, arr.dtype) - - # Ramp values will most likely be float, cast them to the same type as arr - return _do_append(arr, ramp_arr, axis) - - -def _prepend_max(arr, pad_amt, num, axis=-1): +def _get_edges(padded, axis, width_pair): """ - Prepend `pad_amt` maximum values along `axis`. + Retrieve edge values from empty-padded array in given dimension. Parameters ---------- - arr : ndarray - Input array of arbitrary shape. - pad_amt : int - Amount of padding to prepend. - num : int - Depth into `arr` along `axis` to calculate maximum. - Range: [1, `arr.shape[axis]`] or None (entire axis) - axis : int - Axis along which to pad `arr`. - - Returns - ------- - padarr : ndarray - Output array, with `pad_amt` values appended along `axis`. The - prepended region is the maximum of the first `num` values along - `axis`. - - """ - if pad_amt == 0: - return arr - - # Equivalent to edge padding for single value, so do that instead - if num == 1: - return _prepend_edge(arr, pad_amt, axis) - - # Use entire array if `num` is too large - if num is not None: - if num >= arr.shape[axis]: - num = None - - # Slice a chunk from the edge to calculate stats on - max_slice = _slice_first(arr.shape, num, axis=axis) - - # Extract slice, calculate max - max_chunk = arr[max_slice].max(axis=axis, keepdims=True) - - # Concatenate `arr` with `max_chunk`, extended along `axis` by `pad_amt` - return _do_prepend(arr, max_chunk.repeat(pad_amt, axis=axis), axis) - - -def _append_max(arr, pad_amt, num, axis=-1): - """ - Pad one `axis` of `arr` with the maximum of the last `num` elements. - - Parameters - ---------- - arr : ndarray - Input array of arbitrary shape. - pad_amt : int - Amount of padding to append. - num : int - Depth into `arr` along `axis` to calculate maximum. - Range: [1, `arr.shape[axis]`] or None (entire axis) + padded : ndarray + Empty-padded array. axis : int - Axis along which to pad `arr`. + Dimension in which the edges are considered. + width_pair : (int, int) + Pair of widths that mark the pad area on both sides in the given + dimension. Returns ------- - padarr : ndarray - Output array, with `pad_amt` values appended along `axis`. The - appended region is the maximum of the final `num` values along `axis`. - + left_edge, right_edge : ndarray + Edge values of the valid area in `padded` in the given dimension. Its + shape will always match `padded` except for the dimension given by + `axis` which will have a length of 1. """ - if pad_amt == 0: - return arr - - # Equivalent to edge padding for single value, so do that instead - if num == 1: - return _append_edge(arr, pad_amt, axis) - - # Use entire array if `num` is too large - if num is not None: - if num >= arr.shape[axis]: - num = None - - # Slice a chunk from the edge to calculate stats on - if num is not None: - max_slice = _slice_last(arr.shape, num, axis=axis) - else: - max_slice = tuple(slice(None) for x in arr.shape) + left_index = width_pair[0] + left_slice = _slice_at_axis(slice(left_index, left_index + 1), axis) + left_edge = padded[left_slice] - # Extract slice, calculate max - max_chunk = arr[max_slice].max(axis=axis, keepdims=True) + right_index = padded.shape[axis] - width_pair[1] + right_slice = _slice_at_axis(slice(right_index - 1, right_index), axis) + right_edge = padded[right_slice] - # Concatenate `arr` with `max_chunk`, extended along `axis` by `pad_amt` - return _do_append(arr, max_chunk.repeat(pad_amt, axis=axis), axis) + return left_edge, right_edge -def _prepend_mean(arr, pad_amt, num, axis=-1): +def _get_linear_ramps(padded, axis, width_pair, end_value_pair): """ - Prepend `pad_amt` mean values along `axis`. + Construct linear ramps for empty-padded array in given dimension. Parameters ---------- - arr : ndarray - Input array of arbitrary shape. - pad_amt : int - Amount of padding to prepend. - num : int - Depth into `arr` along `axis` to calculate mean. - Range: [1, `arr.shape[axis]`] or None (entire axis) + padded : ndarray + Empty-padded array. axis : int - Axis along which to pad `arr`. + Dimension in which the ramps are constructed. + width_pair : (int, int) + Pair of widths that mark the pad area on both sides in the given + dimension. + end_value_pair : (scalar, scalar) + End values for the linear ramps which form the edge of the fully padded + array. These values are included in the linear ramps. Returns ------- - padarr : ndarray - Output array, with `pad_amt` values prepended along `axis`. The - prepended region is the mean of the first `num` values along `axis`. - + left_ramp, right_ramp : ndarray + Linear ramps to set on both sides of `padded`. """ - if pad_amt == 0: - return arr + edge_pair = _get_edges(padded, axis, width_pair) - # Equivalent to edge padding for single value, so do that instead - if num == 1: - return _prepend_edge(arr, pad_amt, axis) + left_ramp = _linear_ramp( + padded.ndim, axis, start=end_value_pair[0], stop=edge_pair[0], + size=width_pair[0], reverse=False + ) + _round_if_needed(left_ramp, padded.dtype) - # Use entire array if `num` is too large - if num is not None: - if num >= arr.shape[axis]: - num = None + right_ramp = _linear_ramp( + padded.ndim, axis, start=end_value_pair[1], stop=edge_pair[1], + size=width_pair[1], reverse=True + ) + _round_if_needed(right_ramp, padded.dtype) - # Slice a chunk from the edge to calculate stats on - mean_slice = _slice_first(arr.shape, num, axis=axis) + return left_ramp, right_ramp - # Extract slice, calculate mean - mean_chunk = arr[mean_slice].mean(axis, keepdims=True) - _round_ifneeded(mean_chunk, arr.dtype) - # Concatenate `arr` with `mean_chunk`, extended along `axis` by `pad_amt` - return _do_prepend(arr, mean_chunk.repeat(pad_amt, axis), axis=axis) - - -def _append_mean(arr, pad_amt, num, axis=-1): +def _get_stats(padded, axis, width_pair, length_pair, stat_func): """ - Append `pad_amt` mean values along `axis`. + Calculate statistic for the empty-padded array in given dimnsion. Parameters ---------- - arr : ndarray - Input array of arbitrary shape. - pad_amt : int - Amount of padding to append. - num : int - Depth into `arr` along `axis` to calculate mean. - Range: [1, `arr.shape[axis]`] or None (entire axis) + padded : ndarray + Empty-padded array. axis : int - Axis along which to pad `arr`. + Dimension in which the statistic is calculated. + width_pair : (int, int) + Pair of widths that mark the pad area on both sides in the given + dimension. + length_pair : 2-element sequence of None or int + Gives the number of values in valid area from each side that is + taken into account when calculating the statistic. If None the entire + valid area in `padded` is considered. + stat_func : function + Function to compute statistic. The expected signature is + ``stat_func(x: ndarray, axis: int, keepdims: bool) -> ndarray``. Returns ------- - padarr : ndarray - Output array, with `pad_amt` values appended along `axis`. The - appended region is the maximum of the final `num` values along `axis`. - - """ - if pad_amt == 0: - return arr - - # Equivalent to edge padding for single value, so do that instead - if num == 1: - return _append_edge(arr, pad_amt, axis) - - # Use entire array if `num` is too large - if num is not None: - if num >= arr.shape[axis]: - num = None - - # Slice a chunk from the edge to calculate stats on - if num is not None: - mean_slice = _slice_last(arr.shape, num, axis=axis) - else: - mean_slice = tuple(slice(None) for x in arr.shape) - - # Extract slice, calculate mean - mean_chunk = arr[mean_slice].mean(axis=axis, keepdims=True) - _round_ifneeded(mean_chunk, arr.dtype) - - # Concatenate `arr` with `mean_chunk`, extended along `axis` by `pad_amt` - return _do_append(arr, mean_chunk.repeat(pad_amt, axis), axis=axis) - - -def _prepend_med(arr, pad_amt, num, axis=-1): - """ - Prepend `pad_amt` median values along `axis`. + left_stat, right_stat : ndarray + Calculated statistic for both sides of `padded`. + """ + # Calculate indices of the edges of the area with original values + left_index = width_pair[0] + right_index = padded.shape[axis] - width_pair[1] + # as well as its length + max_length = right_index - left_index + + # Limit stat_lengths to max_length + left_length, right_length = length_pair + if left_length is None or max_length < left_length: + left_length = max_length + if right_length is None or max_length < right_length: + right_length = max_length + + # Calculate statistic for the left side + left_slice = _slice_at_axis( + slice(left_index, left_index + left_length), axis) + left_chunk = padded[left_slice] + left_stat = stat_func(left_chunk, axis=axis, keepdims=True) + _round_if_needed(left_stat, padded.dtype) + + if left_length == right_length == max_length: + # return early as right_stat must be identical to left_stat + return left_stat, left_stat + + # Calculate statistic for the right side + right_slice = _slice_at_axis( + slice(right_index - right_length, right_index), axis) + right_chunk = padded[right_slice] + right_stat = stat_func(right_chunk, axis=axis, keepdims=True) + _round_if_needed(right_stat, padded.dtype) + return left_stat, right_stat + + +def _set_reflect_both(padded, axis, width_pair, method, include_edge=False): + """ + Pad `axis` of `arr` with reflection. Parameters ---------- - arr : ndarray + padded : ndarray Input array of arbitrary shape. - pad_amt : int - Amount of padding to prepend. - num : int - Depth into `arr` along `axis` to calculate median. - Range: [1, `arr.shape[axis]`] or None (entire axis) axis : int Axis along which to pad `arr`. - - Returns - ------- - padarr : ndarray - Output array, with `pad_amt` values prepended along `axis`. The - prepended region is the median of the first `num` values along `axis`. - - """ - if pad_amt == 0: - return arr - - # Equivalent to edge padding for single value, so do that instead - if num == 1: - return _prepend_edge(arr, pad_amt, axis) - - # Use entire array if `num` is too large - if num is not None: - if num >= arr.shape[axis]: - num = None - - # Slice a chunk from the edge to calculate stats on - med_slice = _slice_first(arr.shape, num, axis=axis) - - # Extract slice, calculate median - med_chunk = np.median(arr[med_slice], axis=axis, keepdims=True) - _round_ifneeded(med_chunk, arr.dtype) - - # Concatenate `arr` with `med_chunk`, extended along `axis` by `pad_amt` - return _do_prepend(arr, med_chunk.repeat(pad_amt, axis), axis=axis) - - -def _append_med(arr, pad_amt, num, axis=-1): - """ - Append `pad_amt` median values along `axis`. - - Parameters - ---------- - arr : ndarray - Input array of arbitrary shape. - pad_amt : int - Amount of padding to append. - num : int - Depth into `arr` along `axis` to calculate median. - Range: [1, `arr.shape[axis]`] or None (entire axis) - axis : int - Axis along which to pad `arr`. - - Returns - ------- - padarr : ndarray - Output array, with `pad_amt` values appended along `axis`. The - appended region is the median of the final `num` values along `axis`. - - """ - if pad_amt == 0: - return arr - - # Equivalent to edge padding for single value, so do that instead - if num == 1: - return _append_edge(arr, pad_amt, axis) - - # Use entire array if `num` is too large - if num is not None: - if num >= arr.shape[axis]: - num = None - - # Slice a chunk from the edge to calculate stats on - if num is not None: - med_slice = _slice_last(arr.shape, num, axis=axis) - else: - med_slice = tuple(slice(None) for x in arr.shape) - - # Extract slice, calculate median - med_chunk = np.median(arr[med_slice], axis=axis, keepdims=True) - _round_ifneeded(med_chunk, arr.dtype) - - # Concatenate `arr` with `med_chunk`, extended along `axis` by `pad_amt` - return _do_append(arr, med_chunk.repeat(pad_amt, axis), axis=axis) - - -def _prepend_min(arr, pad_amt, num, axis=-1): - """ - Prepend `pad_amt` minimum values along `axis`. - - Parameters - ---------- - arr : ndarray - Input array of arbitrary shape. - pad_amt : int - Amount of padding to prepend. - num : int - Depth into `arr` along `axis` to calculate minimum. - Range: [1, `arr.shape[axis]`] or None (entire axis) - axis : int - Axis along which to pad `arr`. - - Returns - ------- - padarr : ndarray - Output array, with `pad_amt` values prepended along `axis`. The - prepended region is the minimum of the first `num` values along - `axis`. - - """ - if pad_amt == 0: - return arr - - # Equivalent to edge padding for single value, so do that instead - if num == 1: - return _prepend_edge(arr, pad_amt, axis) - - # Use entire array if `num` is too large - if num is not None: - if num >= arr.shape[axis]: - num = None - - # Slice a chunk from the edge to calculate stats on - min_slice = _slice_first(arr.shape, num, axis=axis) - - # Extract slice, calculate min - min_chunk = arr[min_slice].min(axis=axis, keepdims=True) - - # Concatenate `arr` with `min_chunk`, extended along `axis` by `pad_amt` - return _do_prepend(arr, min_chunk.repeat(pad_amt, axis), axis=axis) - - -def _append_min(arr, pad_amt, num, axis=-1): - """ - Append `pad_amt` median values along `axis`. - - Parameters - ---------- - arr : ndarray - Input array of arbitrary shape. - pad_amt : int - Amount of padding to append. - num : int - Depth into `arr` along `axis` to calculate minimum. - Range: [1, `arr.shape[axis]`] or None (entire axis) - axis : int - Axis along which to pad `arr`. - - Returns - ------- - padarr : ndarray - Output array, with `pad_amt` values appended along `axis`. The - appended region is the minimum of the final `num` values along `axis`. - - """ - if pad_amt == 0: - return arr - - # Equivalent to edge padding for single value, so do that instead - if num == 1: - return _append_edge(arr, pad_amt, axis) - - # Use entire array if `num` is too large - if num is not None: - if num >= arr.shape[axis]: - num = None - - # Slice a chunk from the edge to calculate stats on - if num is not None: - min_slice = _slice_last(arr.shape, num, axis=axis) - else: - min_slice = tuple(slice(None) for x in arr.shape) - - # Extract slice, calculate min - min_chunk = arr[min_slice].min(axis=axis, keepdims=True) - - # Concatenate `arr` with `min_chunk`, extended along `axis` by `pad_amt` - return _do_append(arr, min_chunk.repeat(pad_amt, axis), axis=axis) - - -def _pad_ref(arr, pad_amt, method, axis=-1): - """ - Pad `axis` of `arr` by reflection. - - Parameters - ---------- - arr : ndarray - Input array of arbitrary shape. - pad_amt : tuple of ints, length 2 - Padding to (prepend, append) along `axis`. + width_pair : (int, int) + Pair of widths that mark the pad area on both sides in the given + dimension. method : str Controls method of reflection; options are 'even' or 'odd'. - axis : int - Axis along which to pad `arr`. + include_edge : bool + If true, edge value is included in reflection, otherwise the edge + value forms the symmetric axis to the reflection. Returns ------- - padarr : ndarray - Output array, with `pad_amt[0]` values prepended and `pad_amt[1]` - values appended along `axis`. Both regions are padded with reflected - values from the original array. - - Notes - ----- - This algorithm does not pad with repetition, i.e. the edges are not - repeated in the reflection. For that behavior, use `mode='symmetric'`. - - The modes 'reflect', 'symmetric', and 'wrap' must be padded with a - single function, lest the indexing tricks in non-integer multiples of the - original shape would violate repetition in the final iteration. - - """ - # Implicit booleanness to test for zero (or None) in any scalar type - if pad_amt[0] == 0 and pad_amt[1] == 0: - return arr - - ########################################################################## - # Prepended region - - # Slice off a reverse indexed chunk from near edge to pad `arr` before - ref_slice = _slice_at_axis(arr.shape, slice(pad_amt[0], 0, -1), axis=axis) - - ref_chunk1 = arr[ref_slice] - - # Memory/computationally more expensive, only do this if `method='odd'` - if 'odd' in method and pad_amt[0] > 0: - edge_slice1 = _slice_first(arr.shape, 1, axis=axis) - edge_chunk = arr[edge_slice1] - ref_chunk1 = 2 * edge_chunk - ref_chunk1 - del edge_chunk - - ########################################################################## - # Appended region - - # Slice off a reverse indexed chunk from far edge to pad `arr` after - start = arr.shape[axis] - pad_amt[1] - 1 - end = arr.shape[axis] - 1 - ref_slice = _slice_at_axis(arr.shape, slice(start, end), axis=axis) - rev_idx = _slice_at_axis(arr.shape, slice(None, None, -1), axis=axis) - ref_chunk2 = arr[ref_slice][rev_idx] - - if 'odd' in method: - edge_slice2 = _slice_last(arr.shape, 1, axis=axis) - edge_chunk = arr[edge_slice2] - ref_chunk2 = 2 * edge_chunk - ref_chunk2 - del edge_chunk - - # Concatenate `arr` with both chunks, extending along `axis` - return np.concatenate((ref_chunk1, arr, ref_chunk2), axis=axis) - - -def _pad_sym(arr, pad_amt, method, axis=-1): - """ - Pad `axis` of `arr` by symmetry. - - Parameters - ---------- - arr : ndarray - Input array of arbitrary shape. pad_amt : tuple of ints, length 2 - Padding to (prepend, append) along `axis`. - method : str - Controls method of symmetry; options are 'even' or 'odd'. - axis : int - Axis along which to pad `arr`. - - Returns - ------- - padarr : ndarray - Output array, with `pad_amt[0]` values prepended and `pad_amt[1]` - values appended along `axis`. Both regions are padded with symmetric - values from the original array. - - Notes - ----- - This algorithm DOES pad with repetition, i.e. the edges are repeated. - For padding without repeated edges, use `mode='reflect'`. - - The modes 'reflect', 'symmetric', and 'wrap' must be padded with a - single function, lest the indexing tricks in non-integer multiples of the - original shape would violate repetition in the final iteration. - + New index positions of padding to do along the `axis`. If these are + both 0, padding is done in this dimension. """ - # Implicit booleanness to test for zero (or None) in any scalar type - if pad_amt[0] == 0 and pad_amt[1] == 0: - return arr - - ########################################################################## - # Prepended region - - # Slice off a reverse indexed chunk from near edge to pad `arr` before - sym_slice = _slice_first(arr.shape, pad_amt[0], axis=axis) - rev_idx = _slice_at_axis(arr.shape, slice(None, None, -1), axis=axis) - sym_chunk1 = arr[sym_slice][rev_idx] - - # Memory/computationally more expensive, only do this if `method='odd'` - if 'odd' in method and pad_amt[0] > 0: - edge_slice1 = _slice_first(arr.shape, 1, axis=axis) - edge_chunk = arr[edge_slice1] - sym_chunk1 = 2 * edge_chunk - sym_chunk1 - del edge_chunk - - ########################################################################## - # Appended region + left_pad, right_pad = width_pair + old_length = padded.shape[axis] - right_pad - left_pad - # Slice off a reverse indexed chunk from far edge to pad `arr` after - sym_slice = _slice_last(arr.shape, pad_amt[1], axis=axis) - sym_chunk2 = arr[sym_slice][rev_idx] - - if 'odd' in method: - edge_slice2 = _slice_last(arr.shape, 1, axis=axis) - edge_chunk = arr[edge_slice2] - sym_chunk2 = 2 * edge_chunk - sym_chunk2 - del edge_chunk - - # Concatenate `arr` with both chunks, extending along `axis` - return np.concatenate((sym_chunk1, arr, sym_chunk2), axis=axis) - - -def _pad_wrap(arr, pad_amt, axis=-1): - """ - Pad `axis` of `arr` via wrapping. + if include_edge: + # Edge is included, we need to offset the pad amount by 1 + edge_offset = 1 + else: + edge_offset = 0 # Edge is not included, no need to offset pad amount + old_length -= 1 # but must be omitted from the chunk + + if left_pad > 0: + # Pad with reflected values on left side: + # First limit chunk size which can't be larger than pad area + chunk_length = min(old_length, left_pad) + # Slice right to left, stop on or next to edge, start relative to stop + stop = left_pad - edge_offset + start = stop + chunk_length + left_slice = _slice_at_axis(slice(start, stop, -1), axis) + left_chunk = padded[left_slice] + + if method == "odd": + # Negate chunk and align with edge + edge_slice = _slice_at_axis(slice(left_pad, left_pad + 1), axis) + left_chunk = 2 * padded[edge_slice] - left_chunk + + # Insert chunk into padded area + start = left_pad - chunk_length + stop = left_pad + pad_area = _slice_at_axis(slice(start, stop), axis) + padded[pad_area] = left_chunk + # Adjust pointer to left edge for next iteration + left_pad -= chunk_length + + if right_pad > 0: + # Pad with reflected values on right side: + # First limit chunk size which can't be larger than pad area + chunk_length = min(old_length, right_pad) + # Slice right to left, start on or next to edge, stop relative to start + start = -right_pad + edge_offset - 2 + stop = start - chunk_length + right_slice = _slice_at_axis(slice(start, stop, -1), axis) + right_chunk = padded[right_slice] + + if method == "odd": + # Negate chunk and align with edge + edge_slice = _slice_at_axis( + slice(-right_pad - 1, -right_pad), axis) + right_chunk = 2 * padded[edge_slice] - right_chunk + + # Insert chunk into padded area + start = padded.shape[axis] - right_pad + stop = start + chunk_length + pad_area = _slice_at_axis(slice(start, stop), axis) + padded[pad_area] = right_chunk + # Adjust pointer to right edge for next iteration + right_pad -= chunk_length + + return left_pad, right_pad + + +def _set_wrap_both(padded, axis, width_pair): + """ + Pad `axis` of `arr` with wrapped values. Parameters ---------- - arr : ndarray + padded : ndarray Input array of arbitrary shape. - pad_amt : tuple of ints, length 2 - Padding to (prepend, append) along `axis`. axis : int Axis along which to pad `arr`. + width_pair : (int, int) + Pair of widths that mark the pad area on both sides in the given + dimension. Returns ------- - padarr : ndarray - Output array, with `pad_amt[0]` values prepended and `pad_amt[1]` - values appended along `axis`. Both regions are padded wrapped values - from the opposite end of `axis`. - - Notes - ----- - This method of padding is also known as 'tile' or 'tiling'. - - The modes 'reflect', 'symmetric', and 'wrap' must be padded with a - single function, lest the indexing tricks in non-integer multiples of the - original shape would violate repetition in the final iteration. - - """ - # Implicit booleanness to test for zero (or None) in any scalar type - if pad_amt[0] == 0 and pad_amt[1] == 0: - return arr - - ########################################################################## - # Prepended region - - # Slice off a reverse indexed chunk from near edge to pad `arr` before - wrap_slice = _slice_last(arr.shape, pad_amt[0], axis=axis) - wrap_chunk1 = arr[wrap_slice] - - ########################################################################## - # Appended region - - # Slice off a reverse indexed chunk from far edge to pad `arr` after - wrap_slice = _slice_first(arr.shape, pad_amt[1], axis=axis) - wrap_chunk2 = arr[wrap_slice] - - # Concatenate `arr` with both chunks, extending along `axis` - return np.concatenate((wrap_chunk1, arr, wrap_chunk2), axis=axis) + pad_amt : tuple of ints, length 2 + New index positions of padding to do along the `axis`. If these are + both 0, padding is done in this dimension. + """ + left_pad, right_pad = width_pair + period = padded.shape[axis] - right_pad - left_pad + + # If the current dimension of `arr` doesn't contain enough valid values + # (not part of the undefined pad area) we need to pad multiple times. + # Each time the pad area shrinks on both sides which is communicated with + # these variables. + new_left_pad = 0 + new_right_pad = 0 + + if left_pad > 0: + # Pad with wrapped values on left side + # First slice chunk from right side of the non-pad area. + # Use min(period, left_pad) to ensure that chunk is not larger than + # pad area + right_slice = _slice_at_axis( + slice(-right_pad - min(period, left_pad), + -right_pad if right_pad != 0 else None), + axis + ) + right_chunk = padded[right_slice] + + if left_pad > period: + # Chunk is smaller than pad area + pad_area = _slice_at_axis(slice(left_pad - period, left_pad), axis) + new_left_pad = left_pad - period + else: + # Chunk matches pad area + pad_area = _slice_at_axis(slice(None, left_pad), axis) + padded[pad_area] = right_chunk + + if right_pad > 0: + # Pad with wrapped values on right side + # First slice chunk from left side of the non-pad area. + # Use min(period, right_pad) to ensure that chunk is not larger than + # pad area + left_slice = _slice_at_axis( + slice(left_pad, left_pad + min(period, right_pad),), axis) + left_chunk = padded[left_slice] + + if right_pad > period: + # Chunk is smaller than pad area + pad_area = _slice_at_axis( + slice(-right_pad, -right_pad + period), axis) + new_right_pad = right_pad - period + else: + # Chunk matches pad area + pad_area = _slice_at_axis(slice(-right_pad, None), axis) + padded[pad_area] = left_chunk + + return new_left_pad, new_right_pad def _as_pairs(x, ndim, as_index=False): @@ -953,23 +567,23 @@ def _as_pairs(x, ndim, as_index=False): return np.broadcast_to(x, (ndim, 2)).tolist() -############################################################################### -# Public functions - - def _pad_dispatcher(array, pad_width, mode=None, **kwargs): return (array,) +############################################################################### +# Public functions + + @array_function_dispatch(_pad_dispatcher, module='numpy') def pad(array, pad_width, mode='constant', **kwargs): """ - Pads an array. + Pad an array. Parameters ---------- array : array_like of rank N - Input array + The array to pad. pad_width : {sequence, array_like, int} Number of values padded to the edges of each axis. ((before_1, after_1), ... (before_N, after_N)) unique pad widths @@ -1010,6 +624,11 @@ def pad(array, pad_width, mode='constant', **kwargs): Pads with the wrap of the vector along the axis. The first values are used to pad the end and the end values are used to pad the beginning. + 'empty' + Pads with undefined values. + + .. versionadded:: 1.17 + <function> Padding function, see Notes. stat_length : sequence or int, optional @@ -1099,7 +718,7 @@ def pad(array, pad_width, mode='constant', **kwargs): Examples -------- >>> a = [1, 2, 3, 4, 5] - >>> np.pad(a, (2,3), 'constant', constant_values=(4, 6)) + >>> np.pad(a, (2, 3), 'constant', constant_values=(4, 6)) array([4, 4, 1, ..., 6, 6, 6]) >>> np.pad(a, (2, 3), 'edge') @@ -1165,15 +784,30 @@ def pad(array, pad_width, mode='constant', **kwargs): [100, 100, 100, 100, 100, 100, 100], [100, 100, 100, 100, 100, 100, 100]]) """ - if not np.asarray(pad_width).dtype.kind == 'i': + array = np.asarray(array) + pad_width = np.asarray(pad_width) + + if not pad_width.dtype.kind == 'i': raise TypeError('`pad_width` must be of integral type.') - narray = np.array(array) - pad_width = _as_pairs(pad_width, narray.ndim, as_index=True) + # Broadcast to shape (array.ndim, 2) + pad_width = _as_pairs(pad_width, array.ndim, as_index=True) - allowedkwargs = { + if callable(mode): + # Old behavior: Use user-supplied function with np.apply_along_axis + function = mode + # Create a new zero padded array + padded, _ = _pad_simple(array, pad_width, fill_value=0) + # And apply along each axis + for axis in range(padded.ndim): + np.apply_along_axis( + function, axis, padded, pad_width[axis], axis, kwargs) + return padded + + # Make sure that no unsupported keywords were passed for the current mode + allowed_kwargs = { + 'empty': [], 'edge': [], 'wrap': [], 'constant': ['constant_values'], - 'edge': [], 'linear_ramp': ['end_values'], 'maximum': ['stat_length'], 'mean': ['stat_length'], @@ -1181,175 +815,101 @@ def pad(array, pad_width, mode='constant', **kwargs): 'minimum': ['stat_length'], 'reflect': ['reflect_type'], 'symmetric': ['reflect_type'], - 'wrap': [], - } - - kwdefaults = { - 'stat_length': None, - 'constant_values': 0, - 'end_values': 0, - 'reflect_type': 'even', - } - - if isinstance(mode, np.compat.basestring): - # Make sure have allowed kwargs appropriate for mode - for key in kwargs: - if key not in allowedkwargs[mode]: - raise ValueError('%s keyword not in allowed keywords %s' % - (key, allowedkwargs[mode])) - - # Set kwarg defaults - for kw in allowedkwargs[mode]: - kwargs.setdefault(kw, kwdefaults[kw]) - - # Need to only normalize particular keywords. - for i in kwargs: - if i == 'stat_length': - kwargs[i] = _as_pairs(kwargs[i], narray.ndim, as_index=True) - if i in ['end_values', 'constant_values']: - kwargs[i] = _as_pairs(kwargs[i], narray.ndim) - else: - # Drop back to old, slower np.apply_along_axis mode for user-supplied - # vector function - function = mode - - # Create a new padded array - rank = list(range(narray.ndim)) - total_dim_increase = [np.sum(pad_width[i]) for i in rank] - offset_slices = tuple( - slice(pad_width[i][0], pad_width[i][0] + narray.shape[i]) - for i in rank) - new_shape = np.array(narray.shape) + total_dim_increase - newmat = np.zeros(new_shape, narray.dtype) - - # Insert the original array into the padded array - newmat[offset_slices] = narray - - # This is the core of pad ... - for iaxis in rank: - np.apply_along_axis(function, - iaxis, - newmat, - pad_width[iaxis], - iaxis, - kwargs) - return newmat - - # If we get here, use new padding method - newmat = narray.copy() - - # API preserved, but completely new algorithm which pads by building the - # entire block to pad before/after `arr` with in one step, for each axis. - if mode == 'constant': - for axis, ((pad_before, pad_after), (before_val, after_val)) \ - in enumerate(zip(pad_width, kwargs['constant_values'])): - newmat = _prepend_const(newmat, pad_before, before_val, axis) - newmat = _append_const(newmat, pad_after, after_val, axis) - - elif mode == 'edge': - for axis, (pad_before, pad_after) in enumerate(pad_width): - newmat = _prepend_edge(newmat, pad_before, axis) - newmat = _append_edge(newmat, pad_after, axis) - - elif mode == 'linear_ramp': - for axis, ((pad_before, pad_after), (before_val, after_val)) \ - in enumerate(zip(pad_width, kwargs['end_values'])): - newmat = _prepend_ramp(newmat, pad_before, before_val, axis) - newmat = _append_ramp(newmat, pad_after, after_val, axis) - - elif mode == 'maximum': - for axis, ((pad_before, pad_after), (chunk_before, chunk_after)) \ - in enumerate(zip(pad_width, kwargs['stat_length'])): - newmat = _prepend_max(newmat, pad_before, chunk_before, axis) - newmat = _append_max(newmat, pad_after, chunk_after, axis) - - elif mode == 'mean': - for axis, ((pad_before, pad_after), (chunk_before, chunk_after)) \ - in enumerate(zip(pad_width, kwargs['stat_length'])): - newmat = _prepend_mean(newmat, pad_before, chunk_before, axis) - newmat = _append_mean(newmat, pad_after, chunk_after, axis) - - elif mode == 'median': - for axis, ((pad_before, pad_after), (chunk_before, chunk_after)) \ - in enumerate(zip(pad_width, kwargs['stat_length'])): - newmat = _prepend_med(newmat, pad_before, chunk_before, axis) - newmat = _append_med(newmat, pad_after, chunk_after, axis) - - elif mode == 'minimum': - for axis, ((pad_before, pad_after), (chunk_before, chunk_after)) \ - in enumerate(zip(pad_width, kwargs['stat_length'])): - newmat = _prepend_min(newmat, pad_before, chunk_before, axis) - newmat = _append_min(newmat, pad_after, chunk_after, axis) - - elif mode == 'reflect': - for axis, (pad_before, pad_after) in enumerate(pad_width): - if narray.shape[axis] == 0: - # Axes with non-zero padding cannot be empty. - if pad_before > 0 or pad_after > 0: - raise ValueError("There aren't any elements to reflect" - " in axis {} of `array`".format(axis)) - # Skip zero padding on empty axes. - continue - - # Recursive padding along any axis where `pad_amt` is too large - # for indexing tricks. We can only safely pad the original axis - # length, to keep the period of the reflections consistent. - if ((pad_before > 0) or - (pad_after > 0)) and newmat.shape[axis] == 1: + } + try: + unsupported_kwargs = set(kwargs) - set(allowed_kwargs[mode]) + except KeyError: + raise ValueError("mode '{}' is not supported".format(mode)) + if unsupported_kwargs: + raise ValueError("unsupported keyword arguments for mode '{}': {}" + .format(mode, unsupported_kwargs)) + + stat_functions = {"maximum": np.max, "minimum": np.min, + "mean": np.mean, "median": np.median} + + # Create array with final shape and original values + # (padded area is undefined) + padded, original_area_slice = _pad_simple(array, pad_width) + # And prepare iteration over all dimensions + # (zipping may be more readable than using enumerate) + axes = range(padded.ndim) + + if mode == "constant": + values = kwargs.get("constant_values", 0) + values = _as_pairs(values, padded.ndim) + for axis, width_pair, value_pair in zip(axes, pad_width, values): + roi = _view_roi(padded, original_area_slice, axis) + _set_pad_area(roi, axis, width_pair, value_pair) + + elif mode == "empty": + pass # Do nothing as _pad_simple already returned the correct result + + elif array.size == 0: + # Only modes "constant" and "empty" can extend empty axes, all other + # modes depend on `array` not being empty + # -> ensure every empty axis is only "padded with 0" + for axis, width_pair in zip(axes, pad_width): + if array.shape[axis] == 0 and any(width_pair): + raise ValueError( + "can't extend empty axis {} using modes other than " + "'constant' or 'empty'".format(axis) + ) + # passed, don't need to do anything more as _pad_simple already + # returned the correct result + + elif mode == "edge": + for axis, width_pair in zip(axes, pad_width): + roi = _view_roi(padded, original_area_slice, axis) + edge_pair = _get_edges(roi, axis, width_pair) + _set_pad_area(roi, axis, width_pair, edge_pair) + + elif mode == "linear_ramp": + end_values = kwargs.get("end_values", 0) + end_values = _as_pairs(end_values, padded.ndim) + for axis, width_pair, value_pair in zip(axes, pad_width, end_values): + roi = _view_roi(padded, original_area_slice, axis) + ramp_pair = _get_linear_ramps(roi, axis, width_pair, value_pair) + _set_pad_area(roi, axis, width_pair, ramp_pair) + + elif mode in stat_functions: + func = stat_functions[mode] + length = kwargs.get("stat_length", None) + length = _as_pairs(length, padded.ndim, as_index=True) + for axis, width_pair, length_pair in zip(axes, pad_width, length): + roi = _view_roi(padded, original_area_slice, axis) + stat_pair = _get_stats(roi, axis, width_pair, length_pair, func) + _set_pad_area(roi, axis, width_pair, stat_pair) + + elif mode in {"reflect", "symmetric"}: + method = kwargs.get("reflect_type", "even") + include_edge = True if mode == "symmetric" else False + for axis, (left_index, right_index) in zip(axes, pad_width): + if array.shape[axis] == 1 and (left_index > 0 or right_index > 0): # Extending singleton dimension for 'reflect' is legacy # behavior; it really should raise an error. - newmat = _prepend_edge(newmat, pad_before, axis) - newmat = _append_edge(newmat, pad_after, axis) + edge_pair = _get_edges(padded, axis, (left_index, right_index)) + _set_pad_area( + padded, axis, (left_index, right_index), edge_pair) continue - method = kwargs['reflect_type'] - safe_pad = newmat.shape[axis] - 1 - while ((pad_before > safe_pad) or (pad_after > safe_pad)): - pad_iter_b = min(safe_pad, - safe_pad * (pad_before // safe_pad)) - pad_iter_a = min(safe_pad, safe_pad * (pad_after // safe_pad)) - newmat = _pad_ref(newmat, (pad_iter_b, - pad_iter_a), method, axis) - pad_before -= pad_iter_b - pad_after -= pad_iter_a - safe_pad += pad_iter_b + pad_iter_a - newmat = _pad_ref(newmat, (pad_before, pad_after), method, axis) - - elif mode == 'symmetric': - for axis, (pad_before, pad_after) in enumerate(pad_width): - # Recursive padding along any axis where `pad_amt` is too large - # for indexing tricks. We can only safely pad the original axis - # length, to keep the period of the reflections consistent. - method = kwargs['reflect_type'] - safe_pad = newmat.shape[axis] - while ((pad_before > safe_pad) or - (pad_after > safe_pad)): - pad_iter_b = min(safe_pad, - safe_pad * (pad_before // safe_pad)) - pad_iter_a = min(safe_pad, safe_pad * (pad_after // safe_pad)) - newmat = _pad_sym(newmat, (pad_iter_b, - pad_iter_a), method, axis) - pad_before -= pad_iter_b - pad_after -= pad_iter_a - safe_pad += pad_iter_b + pad_iter_a - newmat = _pad_sym(newmat, (pad_before, pad_after), method, axis) - - elif mode == 'wrap': - for axis, (pad_before, pad_after) in enumerate(pad_width): - # Recursive padding along any axis where `pad_amt` is too large - # for indexing tricks. We can only safely pad the original axis - # length, to keep the period of the reflections consistent. - safe_pad = newmat.shape[axis] - while ((pad_before > safe_pad) or - (pad_after > safe_pad)): - pad_iter_b = min(safe_pad, - safe_pad * (pad_before // safe_pad)) - pad_iter_a = min(safe_pad, safe_pad * (pad_after // safe_pad)) - newmat = _pad_wrap(newmat, (pad_iter_b, pad_iter_a), axis) - - pad_before -= pad_iter_b - pad_after -= pad_iter_a - safe_pad += pad_iter_b + pad_iter_a - newmat = _pad_wrap(newmat, (pad_before, pad_after), axis) - - return newmat + roi = _view_roi(padded, original_area_slice, axis) + while left_index > 0 or right_index > 0: + # Iteratively pad until dimension is filled with reflected + # values. This is necessary if the pad area is larger than + # the length of the original values in the current dimension. + left_index, right_index = _set_reflect_both( + roi, axis, (left_index, right_index), + method, include_edge + ) + + elif mode == "wrap": + for axis, (left_index, right_index) in zip(axes, pad_width): + roi = _view_roi(padded, original_area_slice, axis) + while left_index > 0 or right_index > 0: + # Iteratively pad until dimension is filled with wrapped + # values. This is necessary if the pad area is larger than + # the length of the original values in the current dimension. + left_index, right_index = _set_wrap_both( + roi, axis, (left_index, right_index)) + + return padded |