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
dataarray_like

list/array of data values

interfloat (optional; default 90)

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

nint (optional; default 1000)

number of bootstrap iterations

seedint (optional)

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

plotbool (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.

figsizetuple (optional)

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

locint (optional)

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

Returns
outtuple

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, low, high, sample, bars = spacepy.toolbox.bootHisto(
...     data, plot=True)

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

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