AHELP for CIAO 4.11 Sherpa v1

# plot_pdf

Context: plotting

## Synopsis

Plot a binned probability density function.

## Syntax

```plot_pdf(points [, name="x", xlabel="x", bins=12, normed=True,
replot=False, overplot=False, clearwindow=True])```

## Description

The plot_pdf() function plots the probability density function (pdf) of a specified array of histogram values (a NumPY ndarray), using the specified number of data bins (default= 12), plot title, and x-axis label. The pdf is normalized by default (normed=True).

Argument Default Description
points NumPy ndarray of histogram data values
name "x" title to assign to the plot
xlabel "x" label to assign to the x-axis
bins 12 number of bins
normed True Plot a normalized pdf?
replot False Should previously-calculated arrays be used to create the plot?
overplot False If True, then add the data to the current plot, otherwise erase the frame and create a new plot.
clearwindow True If True, then do not delete any existing frames in the current ChIPS window. Note that the plots will be created in a new ChIPS frame even when this argument is set.

## Examples

### Example 1

`plot_pdf(x, bins=50)`

Define a histogram in the variable "x" and plot the corresponding normalized probability density function, with 50 bins.

```sherpa> import numpy as np
sherpa> mu, sigma = 100, 15
sherpa> x = mu + sigma*np.random.randn(10000)
sherpa> plot_pdf(x, bins=50)
```

### Example 2

`plot_pdf(x, name="Energy Flux PDF", xlabel="flux", normed=False)`

Plot the unnormalized probability density function for a simulated energy flux distribution returned by the sample_energy_flux() command (see 'ahelp sample_energy_flux'), using the default number of bins (12).

```sherpa> a = sample_energy_flux(0.5,7.,num=1000)
sherpa> plot_energy_flux()
sherpa> x = a[:,0]
sherpa> plot_pdf(x, name="Energy Flux PDF", xlabel="flux", normed=False)
```

## Bugs

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

contrib
get_data_prof, get_data_prof_prefs, get_delchi_prof, get_delchi_prof_prefs, get_fit_prof, get_model_prof, get_model_prof_prefs, get_resid_prof, get_resid_prof_prefs, get_source_prof, get_source_prof_prefs, plot_chart_spectrum, plot_marx_spectrum, prof_data, prof_delchi, prof_fit, prof_fit_delchi, prof_fit_resid, prof_model, prof_resid, prof_source
data
get_arf_plot, get_bkg_plot
info
list_model_ids, show_bkg_model, show_bkg_source
modeling
add_model, add_user_pars, clean, create_model_component, delete_bkg_model, delete_model, delete_model_component, get_model, get_model_autoassign_func, get_model_component, get_model_component_image, get_model_component_plot, get_model_plot, get_num_par, get_order_plot, get_par, get_pileup_model, get_source, get_source_component_image, get_source_component_plot, image_model, image_model_component, image_source, image_source_component, integrate, link, load_table_model, load_template_model, load_user_model, normal_sample, reset, save_model, save_source, set_bkg_model, set_full_model, set_model_autoassign_func, set_pileup_model, set_source, set_xsabund, set_xscosmo, set_xsxsect, set_xsxset, t_sample, uniform_sample
plotting
get_energy_flux_hist, get_lrt_plot, get_lrt_results, get_photon_flux_hist, get_pvalue_plot, get_pvalue_results, get_split_plot, plot, plot_arf, plot_bkg, plot_cdf, plot_chisqr, plot_data, plot_delchi, plot_energy_flux, plot_fit, plot_model, plot_model_component, plot_order, plot_photon_flux, plot_pvalue, plot_ratio, plot_resid, plot_scatter, plot_source, plot_source_component, plot_trace, set_xlinear, set_xlog, set_ylinear, set_ylog
psfs