#### Previous topic

numpy.polynomial.legendre.legadd

#### Next topic

numpy.polynomial.legendre.legmul

# numpy.polynomial.legendre.legsub

`numpy.polynomial.legendre.``legsub`(c1, c2)

  Subtract one Legendre series from another.

  Returns the difference of two Legendre series c1 - c2. The sequences of coefficients are from lowest order term to highest, i.e., [1,2,3] represents the series `P_0 + 2*P_1 + 3*P_2`.

  Parameters: | c1, c2 : array_like 1-D arrays of Legendre series coefficients ordered from low to high.
  Returns: | out : ndarray Of Legendre series coefficients representing their difference.

  See also

  `legadd`, `legmul`, `legdiv`, `legpow`

  Notes

  Unlike multiplication, division, etc., the difference of two Legendre series is a Legendre series (without having to “reproject” the result onto the basis set) so subtraction, just like that of “standard” polynomials, is simply “component-wise.”

  Examples

      >>> from numpy.polynomial import legendre as L
      >>> c1 = (1,2,3)
      >>> c2 = (3,2,1)
      >>> L.legsub(c1,c2)
      array([-2.,  0.,  2.])
      >>> L.legsub(c2,c1) # -C.legsub(c1,c2)
      array([ 2.,  0., -2.])