Chandra X-Ray Observatory
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Last modified: December 2013

URL: http://cxc.harvard.edu/sherpa/ahelp/delete_psf.html
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AHELP for CIAO 4.9 Sherpa v1

delete_psf

Context: psfs

Synopsis

Delete a PSF model

Syntax

delete_psf( [id] )

Description

The delete_psf command deletes a PSF model from the stack.

  • id - the id of the dataset; if not given, uses the default dataset id (id=1 by default, see "ahelp get_default_id")

What is the difference between the PSF and the kernel?

The point spread function (PSF) is defined by the full (unfiltered) PSF image loaded into Sherpa or the PSF model expression evaluated over the full range of the dataset; both types of PSFs are established with the load_psf() command. The kernel is the subsection of the PSF image or model which is used to convolve the data. This subsection is created from the PSF when the size and center of the kernel are defined by the command set_psf(). While the kernel and PSF might be congruent, defining a smaller kernel helps speed the convolution process by restricting the number of points within the PSF that Sherpa must evaluate.

Example 1

sherpa> delete_psf()

Delete the PSF model for the default source dataset.

Example 2

sherpa> delete_psf("src")

Delete the PSF model associated with the dataset "src".

Bugs

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

See Also

data
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, integrate1d, 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_lrt_plot, get_lrt_results, get_pvalue_plot, get_pvalue_results, plot_cdf, plot_model, plot_model_component, plot_pdf, plot_pvalue, plot_scatter, plot_source, plot_source_component, plot_trace
psfs
contour_kernel, contour_psf, get_kernel, get_psf, image_kernel, image_psf, load_conv, load_psf, plot_kernel, plot_psf, set_psf, show_kernel, show_psf
saving
save_delchi, save_resid
utilities
calc_chisqr, calc_energy_flux, calc_model_sum, calc_photon_flux, calc_source_sum, calc_stat, eqwidth
visualization
contour_model, contour_ratio, contour_resid, get_ratio, get_resid

Last modified: December 2013
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