numpy.polynomial.laguerre.lagmulx

polynomial.laguerre. lagmulx ( c ) [source]

Multiply a Laguerre series by x.

Multiply the Laguerre series c by x, where x is the independent variable.

Parameters

c array_like

1-D array of Laguerre series coefficients ordered from low to high.

Returns

out ndarray

Array representing the result of the multiplication.

See also

lagadd, lagsub, lagmul, lagdiv, lagpow

Notes

The multiplication uses the recursion relationship for Laguerre polynomials in the form

\[xP_i(x) = (-(i + 1)*P_{i + 1}(x) + (2i + 1)P_{i}(x) - iP_{i - 1}(x))\]

Examples

>>> from numpy.polynomial.laguerre import lagmulx
>>> lagmulx([1, 2, 3])
array([-1.,  -1.,  11.,  -9.])