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Last modified: December 2006

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

Synopsis

An alternative form of DATASPACE and set_axes().

Syntax

set_dataspace( dnum, elo, ehi, estep );

Description

The routine is loaded into Sherpa with the call

  require ("sherpa_utils");

This routine sets the X-axis grid of the given "dataset" (the dnum parameter; it should be an integer >= 1) to cover the range elo to ehi with a bin width of estep. The elo/ehi/estep parameters should generally be considered to be in units of keV but it depends on the model being used.

The grid is set up in "HISTOGRAM" mode (see "ahelp integrate") so the points go from elo to elo+estep, elo+estep to elo+2*estep, etc. The behaviour at the ehi end is not well determined in the current version of this routine: it is not guaranteed to stop at ehi if (ehi-elo)/estep does not evaluate to an integer value.

This routine is just a simple wrapper around the set_axes() function - see "ahelp set_axes" for more information.

Example 1

sherpa> set_dataspace()
Usage:
set_dataspace( dnum, elo, ehi, estep )

If called with the incorrect number of arguments (here none) the routine will display a brief usage message.

Example 2

sherpa> set_dataspace(1,0.1,10,0.01)

This is equivalent to calling:

  sherpa> dataspace (0.1:10:0.01) histogram

Example 3

sherpa> set_dataspace(2,0.1,10,0.01)

This is equivalent to calling:

  sherpa> dataspace 2 (0.1:10:0.01) histogram

NOTES

Please see "ahelp sherpa_utils" for information on how to load these routines into Sherpa.

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



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