spacepy.toolbox.bootHisto

spacepy.toolbox.bootHisto(data, inter=90.0, n=1000, seed=None, plot=False, target=None, figsize=None, loc=None, **kwargs)[source]

Bootstrap confidence intervals for a histogram.

All other keyword arguments are passed to numpy.histogram() or matplotlib.pyplot.bar().

Parameters:

data : array_like

list/array of data values

inter : float (optional; default 90)

percentage confidence interval to return. Default 90% (i.e. lower CI will be 5% and upper will be 95%)

n : int (optional; default 100)

number of bootstrap iterations

seed : int (optional)

Optional seed for the random number generator. If not specified; numpy generator will not be reseeded.

plot : bool (optional)

Plot the result. Plots if True or target, figsize, or loc specified.

target : (optional)

Target on which to plot the figure (figure or axes). See spacepy.plot.utils.set_target() for details.

figsize : tuple (optional)

Passed to spacepy.plot.utils.set_target().

loc : int (optional)

Passed to spacepy.plot.utils.set_target().

Returns:

out : tuple

tuple of bin_edges, low, high, sample[, bars]. Where bin_edges is the edges of the bins used; low is the histogram with the value for each bin from the bottom of that bin’s confidence interval; high similarly for the top; sample is the histogram of the input sample without resampling. If plotting, also returned is bars, the container object returned from matplotlib.

See also

binHisto, plot.utils.set_target, numpy.histogram, matplotlib.pyplot.hist

Notes

The confidence intervals are calculated for each bin individually and thus the resulting low/high histograms may not have actually occurred in the calculation from the surrogates. If using a probability density histogram, this can have “interesting” implications for interpretation.

Examples

>>> import numpy.random
>>> import spacepy.toolbox
>>> numpy.random.seed(0)
>>> data = numpy.random.randn(1000)
>>> bin_edges, ci_low, ci_high, sample, bars = spacepy.toolbox.bootHisto(
        data, plot=True)

(Source code, png, hires.png, pdf)

../_images/spacepy-toolbox-bootHisto-1.png