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# numpy.expm1

`numpy.``expm1`(x[, out]) = <ufunc 'expm1'>

  Calculate `exp(x) - 1` for all elements in the array.

  Parameters: | x : array_like Input values.
  Returns: | out : ndarray Element-wise exponential minus one: `out = exp(x) - 1`.

  See also

  `log1p`
    `log(1 + x)`, the inverse of expm1.

  Notes

  This function provides greater precision than `exp(x) - 1` for small values of `x`.

  Examples

  The true value of `exp(1e-10) - 1` is `1.00000000005e-10` to about 32 significant digits. This example shows the superiority of expm1 in this case.

      >>> np.expm1(1e-10)
      1.00000000005e-10
      >>> np.exp(1e-10) - 1
      1.000000082740371e-10