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author | David Cournapeau <cournape@gmail.com> | 2009-09-16 07:13:23 +0000 |
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committer | David Cournapeau <cournape@gmail.com> | 2009-09-16 07:13:23 +0000 |
commit | f72c2dfd7d188f1ee9d795ba66c001aa7263c319 (patch) | |
tree | acb0dac165305a66ed77e682ebedfb6ac6cb0c6a /numpy/lib/function_base.py | |
parent | a0a2b2bba65baaa1ab88fef3995911c14adaf2d4 (diff) | |
download | numpy-f72c2dfd7d188f1ee9d795ba66c001aa7263c319.tar.gz |
Move linspace and logspace into core.
Diffstat (limited to 'numpy/lib/function_base.py')
-rw-r--r-- | numpy/lib/function_base.py | 158 |
1 files changed, 2 insertions, 156 deletions
diff --git a/numpy/lib/function_base.py b/numpy/lib/function_base.py index 663c3d2ef..2459ffc23 100644 --- a/numpy/lib/function_base.py +++ b/numpy/lib/function_base.py @@ -1,6 +1,5 @@ __docformat__ = "restructuredtext en" -__all__ = ['logspace', 'linspace', - 'select', 'piecewise', 'trim_zeros', +__all__ = ['select', 'piecewise', 'trim_zeros', 'copy', 'iterable', 'diff', 'gradient', 'angle', 'unwrap', 'sort_complex', 'disp', 'extract', 'place', 'nansum', 'nanmax', 'nanargmax', @@ -15,6 +14,7 @@ import warnings import types import numpy.core.numeric as _nx +from numpy.core import linspace from numpy.core.numeric import ones, zeros, arange, concatenate, array, \ asarray, asanyarray, empty, empty_like, ndarray, around from numpy.core.numeric import ScalarType, dot, where, newaxis, intp, \ @@ -33,160 +33,6 @@ import numpy as np #end Fernando's utilities -def linspace(start, stop, num=50, endpoint=True, retstep=False): - """ - Return evenly spaced numbers over a specified interval. - - Returns `num` evenly spaced samples, calculated over the - interval [`start`, `stop` ]. - - The endpoint of the interval can optionally be excluded. - - Parameters - ---------- - start : scalar - The starting value of the sequence. - stop : scalar - The end value of the sequence, unless `endpoint` is set to False. - In that case, the sequence consists of all but the last of ``num + 1`` - evenly spaced samples, so that `stop` is excluded. Note that the step - size changes when `endpoint` is False. - num : int, optional - Number of samples to generate. Default is 50. - endpoint : bool, optional - If True, `stop` is the last sample. Otherwise, it is not included. - Default is True. - retstep : bool, optional - If True, return (`samples`, `step`), where `step` is the spacing - between samples. - - Returns - ------- - samples : ndarray - There are `num` equally spaced samples in the closed interval - ``[start, stop]`` or the half-open interval ``[start, stop)`` - (depending on whether `endpoint` is True or False). - step : float (only if `retstep` is True) - Size of spacing between samples. - - - See Also - -------- - arange : Similiar to `linspace`, but uses a step size (instead of the - number of samples). - logspace : Samples uniformly distributed in log space. - - Examples - -------- - >>> np.linspace(2.0, 3.0, num=5) - array([ 2. , 2.25, 2.5 , 2.75, 3. ]) - >>> np.linspace(2.0, 3.0, num=5, endpoint=False) - array([ 2. , 2.2, 2.4, 2.6, 2.8]) - >>> np.linspace(2.0, 3.0, num=5, retstep=True) - (array([ 2. , 2.25, 2.5 , 2.75, 3. ]), 0.25) - - Graphical illustration: - - >>> import matplotlib.pyplot as plt - >>> N = 8 - >>> y = np.zeros(N) - >>> x1 = np.linspace(0, 10, N, endpoint=True) - >>> x2 = np.linspace(0, 10, N, endpoint=False) - >>> plt.plot(x1, y, 'o') - >>> plt.plot(x2, y + 0.5, 'o') - >>> plt.ylim([-0.5, 1]) - >>> plt.show() - - """ - num = int(num) - if num <= 0: - return array([], float) - if endpoint: - if num == 1: - return array([float(start)]) - step = (stop-start)/float((num-1)) - y = _nx.arange(0, num) * step + start - y[-1] = stop - else: - step = (stop-start)/float(num) - y = _nx.arange(0, num) * step + start - if retstep: - return y, step - else: - return y - -def logspace(start,stop,num=50,endpoint=True,base=10.0): - """ - Return numbers spaced evenly on a log scale. - - In linear space, the sequence starts at ``base ** start`` - (`base` to the power of `start`) and ends with ``base ** stop`` - (see `endpoint` below). - - Parameters - ---------- - start : float - ``base ** start`` is the starting value of the sequence. - stop : float - ``base ** stop`` is the final value of the sequence, unless `endpoint` - is False. In that case, ``num + 1`` values are spaced over the - interval in log-space, of which all but the last (a sequence of - length ``num``) are returned. - num : integer, optional - Number of samples to generate. Default is 50. - endpoint : boolean, optional - If true, `stop` is the last sample. Otherwise, it is not included. - Default is True. - base : float, optional - The base of the log space. The step size between the elements in - ``ln(samples) / ln(base)`` (or ``log_base(samples)``) is uniform. - Default is 10.0. - - Returns - ------- - samples : ndarray - `num` samples, equally spaced on a log scale. - - See Also - -------- - arange : Similiar to linspace, with the step size specified instead of the - number of samples. Note that, when used with a float endpoint, the - endpoint may or may not be included. - linspace : Similar to logspace, but with the samples uniformly distributed - in linear space, instead of log space. - - Notes - ----- - Logspace is equivalent to the code - - >>> y = linspace(start, stop, num=num, endpoint=endpoint) - >>> power(base, y) - - Examples - -------- - >>> np.logspace(2.0, 3.0, num=4) - array([ 100. , 215.443469 , 464.15888336, 1000. ]) - >>> np.logspace(2.0, 3.0, num=4, endpoint=False) - array([ 100. , 177.827941 , 316.22776602, 562.34132519]) - >>> np.logspace(2.0, 3.0, num=4, base=2.0) - array([ 4. , 5.0396842 , 6.34960421, 8. ]) - - Graphical illustration: - - >>> import matplotlib.pyplot as plt - >>> N = 10 - >>> x1 = np.logspace(0.1, 1, N, endpoint=True) - >>> x2 = np.logspace(0.1, 1, N, endpoint=False) - >>> y = np.zeros(N) - >>> plt.plot(x1, y, 'o') - >>> plt.plot(x2, y + 0.5, 'o') - >>> plt.ylim([-0.5, 1]) - >>> plt.show() - - """ - y = linspace(start,stop,num=num,endpoint=endpoint) - return _nx.power(base,y) - def iterable(y): try: iter(y) except: return 0 |