# numpy.logspace

numpy.logspace(start, stop, num=50, endpoint=True, base=10.0, dtype=None, axis=0)

  Return numbers spaced evenly on a log scale.

  In linear space, the sequence starts at `base ** start` (base to the power of start) and ends with `base ** stop` (see endpoint below).

  Changed in version 1.16.0: Non-scalar start and stop are now supported.

  Parameters
    start array_like

      `base ** start` is the starting value of the sequence.

    stop array_like

      `base ** stop` is the final value of the sequence, unless endpoint is False. In that case, `num + 1` values are spaced over the interval in log-space, of which all but the last (a sequence of length num) are returned.

    num integer, optional

      Number of samples to generate. Default is 50.

    endpoint boolean, optional

      If true, stop is the last sample. Otherwise, it is not included. Default is True.

    base array_like, optional

      The base of the log space. The step size between the elements in `ln(samples) / ln(base)` (or `log_base(samples)`) is uniform. Default is 10.0.

    dtype dtype

      The type of the output array. If `dtype` is not given, the data type is inferred from start and stop. The inferred type will never be an integer; `float` is chosen even if the arguments would produce an array of integers.

    axis int, optional

      The axis in the result to store the samples. Relevant only if start or stop are array-like. By default (0), the samples will be along a new axis inserted at the beginning. Use -1 to get an axis at the end.

      New in version 1.16.0.

  Returns
    samples ndarray

      num samples, equally spaced on a log scale.

  See also

  `arange`

    Similar to linspace, with the step size specified instead of the number of samples. Note that, when used with a float endpoint, the endpoint may or may not be included.

  `linspace`

    Similar to logspace, but with the samples uniformly distributed in linear space, instead of log space.

  `geomspace`

    Similar to logspace, but with endpoints specified directly.

  Notes

  Logspace is equivalent to the code

      >>> y = np.linspace(start, stop, num=num, endpoint=endpoint)
      ...
      >>> power(base, y).astype(dtype)
      ...

  Examples

      >>> np.logspace(2.0, 3.0, num=4)
      array([ 100.        ,  215.443469  ,  464.15888336, 1000.        ])
      >>> np.logspace(2.0, 3.0, num=4, endpoint=False)
      array([100.        ,  177.827941  ,  316.22776602,  562.34132519])
      >>> np.logspace(2.0, 3.0, num=4, base=2.0)
      array([4.        ,  5.0396842 ,  6.34960421,  8.        ])

  Graphical illustration:

      >>> import matplotlib.pyplot as plt
      >>> N = 10
      >>> x1 = np.logspace(0.1, 1, N, endpoint=True)
      >>> x2 = np.logspace(0.1, 1, N, endpoint=False)
      >>> y = np.zeros(N)
      >>> plt.plot(x1, y, 'o')
      [<matplotlib.lines.Line2D object at 0x...>]
      >>> plt.plot(x2, y + 0.5, 'o')
      [<matplotlib.lines.Line2D object at 0x...>]
      >>> plt.ylim([-0.5, 1])
      (-0.5, 1)
      >>> plt.show()

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