Differentiate a Laguerre series.
Returns the series cs differentiated m times. At each iteration the result is multiplied by scl (the scaling factor is for use in a linear change of variable). The argument cs is the sequence of coefficients from lowest order “term” to highest, e.g., [1,2,3] represents the series P_0 + 2*P_1 + 3*P_2.
Parameters : | cs: array_like :
m : int, optional
scl : scalar, optional
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Returns : | der : ndarray
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See also
Notes
In general, the result of differentiating a Laguerre series does not resemble the same operation on a power series. Thus the result of this function may be “un-intuitive,” albeit correct; see Examples section below.
Examples
>>> from numpy.polynomial.laguerre import lagder
>>> lagder([ 1., 1., 1., -3.])
array([ 1., 2., 3.])
>>> lagder([ 1., 0., 0., -4., 3.], m=2)
array([ 1., 2., 3.])