pascal#
- scipy.linalg.pascal(n,kind='symmetric',exact=True)[source]#
Returns the n x n Pascal matrix.
The Pascal matrix is a matrix containing the binomial coefficients asits elements.
- Parameters:
- nint
The size of the matrix to create; that is, the result is an n x nmatrix.
- kindstr, optional
Must be one of ‘symmetric’, ‘lower’, or ‘upper’.Default is ‘symmetric’.
- exactbool, optional
Ifexact is True, the result is either an array of typenumpy.uint64 (if n < 35) or an object array of Python long integers.Ifexact is False, the coefficients in the matrix are computed using
scipy.special.combwithexact=False. The result will be a floatingpoint array, and the values in the array will not be the exactcoefficients, but this version is much faster thanexact=True.
- Returns:
- p(n, n) ndarray
The Pascal matrix.
See also
Notes
Seehttps://en.wikipedia.org/wiki/Pascal_matrix for more informationabout Pascal matrices.
Added in version 0.11.0.
Examples
>>>fromscipy.linalgimportpascal>>>pascal(4)array([[ 1, 1, 1, 1], [ 1, 2, 3, 4], [ 1, 3, 6, 10], [ 1, 4, 10, 20]], dtype=uint64)>>>pascal(4,kind='lower')array([[1, 0, 0, 0], [1, 1, 0, 0], [1, 2, 1, 0], [1, 3, 3, 1]], dtype=uint64)>>>pascal(50)[-1,-1]25477612258980856902730428600>>>fromscipy.specialimportcomb>>>comb(98,49,exact=True)25477612258980856902730428600