# numpy.polynomial.hermite_e.hermemul¶

`numpy.polynomial.hermite_e.``hermemul`(c1, c2)[source]

Multiply one Hermite series by another.

Returns the product of two Hermite series c1 * c2. The arguments are sequences 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: c1, c2 : array_like 1-D arrays of Hermite series coefficients ordered from low to high. out : ndarray Of Hermite series coefficients representing their product.

Notes

In general, the (polynomial) product of two C-series results in terms that are not in the Hermite polynomial basis set. Thus, to express the product as a Hermite series, it is necessary to “reproject” the product onto said basis set, which may produce “unintuitive” (but correct) results; see Examples section below.

Examples

```>>> from numpy.polynomial.hermite_e import hermemul
>>> hermemul([1, 2, 3], [0, 1, 2])
array([ 14.,  15.,  28.,   7.,   6.])
```

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