numpy.polynomial.legendre.legmulx¶
- polynomial.legendre.legmulx(c)[source]¶
Multiply a Legendre series by x.
Multiply the Legendre series c by x, where x is the independent variable.
- Parameters
- carray_like
1-D array of Legendre series coefficients ordered from low to high.
- Returns
- outndarray
Array representing the result of the multiplication.
Notes
The multiplication uses the recursion relationship for Legendre polynomials in the form
\[xP_i(x) = ((i + 1)*P_{i + 1}(x) + i*P_{i - 1}(x))/(2i + 1)\]Examples
>>> from numpy.polynomial import legendre as L >>> L.legmulx([1,2,3]) array([ 0.66666667, 2.2, 1.33333333, 1.8]) # may vary