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Last modified: December 2006

URL: http://cxc.harvard.edu/ciao3.4/get_arf_axes.html
Hardcopy (PDF): A4 | Letter
AHELP for CIAO 3.4 get_arf_axes Context: sherpa

Synopsis

Module functions to retrieve the energy/wavelength grid of an ARF associated with source and background data

Syntax

Struct_Type get_arf_axes([Integer_Type])
Struct_Type get_arf_baxes([Integer_Type])

Error Return Value: NULL

Arguments:

(1) data set number (default 1)

Description

In Sherpa parlance, a ``dataspace'' is an N-dimensional grid defined by the independent variables of the dataset (i.e., x_i in the expression y = f(x_0, x_1,...,x_(N-1))). Simple examples include the CHANNELS array in PHA datasets and the pixel numbers along each axis of FITS images.

The get_arf_axes() function returns a variable of Struct_Type, which is equivalent to that returned by get_axes(). The only difference is that the fields lo and hi contain data from the ENERG_LO and ENERG_HI columns from the input ARF file.

One may display the ARF on the same grid using the Sherpa plotting command LPLOT ARF.

Bugs

See the Sherpa bug pages online for an up-to-date listing of known bugs.

Hardcopy (PDF): A4 | Letter
Last modified: December 2006



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