Did I find the right examples for you? yes no

# numpy.polynomial.laguerre.lagmulx

All Samples(6)  |  Call(6)  |  Derive(0)  |  Import(0)
```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(more...)
```

```        def lagmulx(c):
"""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.

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

.. math::

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.])

"""
# c is a trimmed copy
[c] = pu.as_series([c])
# The zero series needs special treatment
if len(c) == 1 and c[0] == 0:
return c

prd = np.empty(len(c) + 1, dtype=c.dtype)
prd[0] = c[0]
prd[1] = -c[0]
for i in range(1, len(c)):
prd[i + 1] = -c[i]*(i + 1)
prd[i] += c[i]*(2*i + 1)
prd[i - 1] -= c[i]*i
return prd
```

```    def test_lagmulx(self):
assert_equal(lag.lagmulx([0]), [0])
assert_equal(lag.lagmulx([1]), [1,-1])
for i in range(1, 5):
ser = [0]*i + [1]
tgt = [0]*(i - 1) + [-i, 2*i + 1, -(i + 1)]
assert_almost_equal(lag.lagmulx(ser), tgt)
```

```    def test_lagmulx(self):