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authorPauli Virtanen <pav@iki.fi>2009-10-02 19:27:46 +0000
committerPauli Virtanen <pav@iki.fi>2009-10-02 19:27:46 +0000
commit1521f6689a3cc48d60a75097a7ffcf4d51f9dc47 (patch)
treea0f048838717b7ee43177007ec42c3102ea7be25 /numpy/lib/twodim_base.py
parent8c7d1bc554e6b5bbb7900a2f6d976d72795bb454 (diff)
downloadnumpy-1521f6689a3cc48d60a75097a7ffcf4d51f9dc47.tar.gz
Docstring updates, part 1
Diffstat (limited to 'numpy/lib/twodim_base.py')
-rw-r--r--numpy/lib/twodim_base.py123
1 files changed, 74 insertions, 49 deletions
diff --git a/numpy/lib/twodim_base.py b/numpy/lib/twodim_base.py
index e794d4144..46294fbd9 100644
--- a/numpy/lib/twodim_base.py
+++ b/numpy/lib/twodim_base.py
@@ -632,15 +632,27 @@ def mask_indices(n,mask_func,k=0):
def tril_indices(n,k=0):
- """Return the indices for the lower-triangle of an (n,n) array.
+ """
+ Return the indices for the lower-triangle of an (n, n) array.
Parameters
----------
n : int
Sets the size of the arrays for which the returned indices will be valid.
-
k : int, optional
- Diagonal offset (see tril() for details).
+ Diagonal offset (see `tril` for details).
+
+ Returns
+ -------
+ inds : tuple of arrays
+ The indices for the triangle. The returned tuple contains two arrays,
+ each with the indices along one dimension of the array.
+
+ See also
+ --------
+ triu_indices : similar function, for upper-triangular.
+ mask_indices : generic function accepting an arbitrary mask function.
+ tril, triu
Notes
-----
@@ -648,45 +660,45 @@ def tril_indices(n,k=0):
Examples
--------
- Commpute two different sets of indices to access 4x4 arrays, one for the
+ Compute two different sets of indices to access 4x4 arrays, one for the
lower triangular part starting at the main diagonal, and one starting two
diagonals further right:
-
- >>> il1 = tril_indices(4)
- >>> il2 = tril_indices(4,2)
+
+ >>> il1 = np.tril_indices(4)
+ >>> il2 = np.tril_indices(4, 2)
Here is how they can be used with a sample array:
- >>> a = np.array([[1,2,3,4],[5,6,7,8],[9,10,11,12],[13,14,15,16]])
+
+ >>> a = np.arange(16).reshape(4, 4)
>>> a
- array([[ 1, 2, 3, 4],
- [ 5, 6, 7, 8],
- [ 9, 10, 11, 12],
- [13, 14, 15, 16]])
+ array([[ 0, 1, 2, 3],
+ [ 4, 5, 6, 7],
+ [ 8, 9, 10, 11],
+ [12, 13, 14, 15]])
Both for indexing:
+
>>> a[il1]
- array([ 1, 5, 6, 9, 10, 11, 13, 14, 15, 16])
+ array([ 0, 4, 5, 8, 9, 10, 12, 13, 14, 15])
And for assigning values:
+
>>> a[il1] = -1
>>> a
- array([[-1, 2, 3, 4],
- [-1, -1, 7, 8],
- [-1, -1, -1, 12],
+ array([[-1, 1, 2, 3],
+ [-1, -1, 6, 7],
+ [-1, -1, -1, 11],
[-1, -1, -1, -1]])
These cover almost the whole array (two diagonals right of the main one):
- >>> a[il2] = -10
+
+ >>> a[il2] = -10
>>> a
- array([[-10, -10, -10, 4],
+ array([[-10, -10, -10, 3],
[-10, -10, -10, -10],
[-10, -10, -10, -10],
[-10, -10, -10, -10]])
- See also
- --------
- - triu_indices : similar function, for upper-triangular.
- - mask_indices : generic function accepting an arbitrary mask function.
"""
return mask_indices(n,tril,k)
@@ -715,15 +727,27 @@ def tril_indices_from(arr,k=0):
def triu_indices(n,k=0):
- """Return the indices for the upper-triangle of an (n,n) array.
+ """
+ Return the indices for the upper-triangle of an (n, n) array.
Parameters
----------
n : int
Sets the size of the arrays for which the returned indices will be valid.
-
k : int, optional
- Diagonal offset (see triu() for details).
+ Diagonal offset (see `triu` for details).
+
+ Returns
+ -------
+ inds : tuple of arrays
+ The indices for the triangle. The returned tuple contains two arrays,
+ each with the indices along one dimension of the array.
+
+ See also
+ --------
+ tril_indices : similar function, for lower-triangular.
+ mask_indices : generic function accepting an arbitrary mask function.
+ triu, tril
Notes
-----
@@ -731,45 +755,46 @@ def triu_indices(n,k=0):
Examples
--------
- Commpute two different sets of indices to access 4x4 arrays, one for the
- lower triangular part starting at the main diagonal, and one starting two
+ Compute two different sets of indices to access 4x4 arrays, one for the
+ upper triangular part starting at the main diagonal, and one starting two
diagonals further right:
- >>> iu1 = triu_indices(4)
- >>> iu2 = triu_indices(4,2)
+ >>> iu1 = np.triu_indices(4)
+ >>> iu2 = np.triu_indices(4, 2)
Here is how they can be used with a sample array:
- >>> a = np.array([[1,2,3,4],[5,6,7,8],[9,10,11,12],[13,14,15,16]])
+
+ >>> a = np.arange(16).reshape(4, 4)
>>> a
- array([[ 1, 2, 3, 4],
- [ 5, 6, 7, 8],
- [ 9, 10, 11, 12],
- [13, 14, 15, 16]])
+ array([[ 0, 1, 2, 3],
+ [ 4, 5, 6, 7],
+ [ 8, 9, 10, 11],
+ [12, 13, 14, 15]])
Both for indexing:
- >>> a[il1]
- array([ 1, 5, 6, 9, 10, 11, 13, 14, 15, 16])
- And for assigning values:
- >>> a[iu] = -1
+ >>> a[iu1]
+ array([ 0, 1, 2, 3, 5, 6, 7, 10, 11, 15])
+
+ And for assigning values:
+
+ >>> a[iu1] = -1
>>> a
array([[-1, -1, -1, -1],
- [ 5, -1, -1, -1],
- [ 9, 10, -1, -1],
- [13, 14, 15, -1]])
+ [ 4, -1, -1, -1],
+ [ 8, 9, -1, -1],
+ [12, 13, 14, -1]])
+
+ These cover only a small part of the whole array (two diagonals right
+ of the main one):
- These cover almost the whole array (two diagonals right of the main one):
>>> a[iu2] = -10
>>> a
array([[ -1, -1, -10, -10],
- [ 5, -1, -1, -10],
- [ 9, 10, -1, -1],
- [ 13, 14, 15, -1]])
+ [ 4, -1, -1, -10],
+ [ 8, 9, -1, -1],
+ [ 12, 13, 14, -1]])
- See also
- --------
- - tril_indices : similar function, for lower-triangular.
- - mask_indices : generic function accepting an arbitrary mask function.
"""
return mask_indices(n,triu,k)