Last modified: December 2023

URL: https://cxc.cfa.harvard.edu/sherpa/ahelp/histogram1d.html
AHELP for CIAO 4.16 Sherpa

histogram1d

Context: visualization

Synopsis

Create a 1D histogram from a sequence of samples.

Syntax

histogram1d(x, x_lo, x_hi)

x - sequence of numbers
x_lo - sequence of numbers
x_hi - sequence of numbers

Description

See the `numpy.histogram` routine for a version with more options.


Examples

Example 1

A simple example, calculating the histogram of 1000 values randomly distributed over [0, 1).

>>> import numpy as np
>>> rng = np.random.default_rng()
>>> x = rng.random(1000)
>>> edges = np.linspace(0, 1, 11)
>>> xlo = edges[:-1]
>>> xhi = edges[1:]
>>> y = histogram1d(x, xlo, xhi)

Example 2

Given a list of samples, bin them up so that they can be used as the dependent axis (the value to be fitted) in a Sherpa data set:

>>> dataspace1d(1, 10, 1)
>>> lo, hi = get_indep()
>>> n = histogram1d([2, 3, 2, 8, 5, 2], lo, hi)
>>> set_dep(n)

PARAMETERS

The parameters for this function are:

Parameter Definition
x The array of samples
x_lo The lower-edges of each bin.
x_hi The upper-edges of each bin, which must be the same size as x_lo .

Return value

The return value from this function is:

y -- The number of samples in each histogram bin defined by the x_lo and x_hi arrays.

Changes in CIAO

Changed in CIAO 4.15

The x_lo and x_hi arguments are no-longer changed (sorted) by this routine.


Bugs

See the bugs pages on the Sherpa website for an up-to-date listing of known bugs.

See Also

data
copy_data, dataspace1d, dataspace2d, datastack, delete_data, fake, get_axes, get_bkg_chisqr_plot, get_bkg_delchi_plot, get_bkg_fit_plot, get_bkg_model_plot, get_bkg_plot, get_bkg_ratio_plot, get_bkg_resid_plot, get_bkg_source_plot, get_counts, get_data, get_data_contour, get_data_contour_prefs, get_data_image, get_data_plot, get_data_plot_prefs, get_dep, get_dims, get_error, get_quality, get_specresp, get_staterror, get_syserror, group, group_adapt, group_adapt_snr, group_bins, group_counts, group_snr, group_width, load_ascii, load_data, load_grouping, load_quality, set_data, set_quality, ungroup, unpack_ascii, unpack_data
filtering
get_filter, load_filter, set_filter
info
get_default_id, list_data_ids, list_response_ids
modeling
clean
plotting
plot_data, set_xlinear, set_xlog, set_ylinear, set_ylog
saving
save_error, save_filter, save_grouping, save_quality, save_staterror, save_syserror
utilities
calc_data_sum, calc_data_sum2d, calc_ftest, calc_kcorr, calc_mlr, calc_model_sum2d, calc_source_sum2d, get_rate
visualization
contour, contour_data, contour_ratio, histogram2d, image_data, rebin