freqtochan.pro

NRAO GBTIDL
Produced by IDL 6.1
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SUMMARY: fields | routine DETAILS: routine

./toolbox
File freqtochan.pro

Last modification date:: Tue Nov 30 10:42:58 2004

freqtochan

function freqtochan(data, freqs, [frame=string], [/rel], [true_frame=string])

Convert frequency (MHz) channel number using the supplied data container. The frequency may be expressed in another reference frame or relative to the reference channel.

Returns: channel number.
Uses: data_valid frame_velocity
Version: $Id: freqtochan.pro,v 1.1 2004/11/30 15:42:58 bgarwood Exp $

Parameters

data
in, required
spectrum The spectrum data container to use to get the necessary header information.

freqs
in, required
The frequencies to convert (MHz), may be an array of values.

Keywords

frame
in, optional
string The rest frame that the frequencies are in. Known rest frames are listed in freqtovel. Defaults to the frame given in the data container.

rel
in, optional
boolean If set, the frequencies are relative to the reference channel.

true_frame
out, optional
string The actual rest frame used in converting the frequencies. The only way this will not equal the frame argument is if that argument was invalid. In that case, this keyword will be the same as the frame in data.frequency_type.

Produced by IDLdoc 1.5 on Wed Dec 8 13:08:16 2004

Parameters
data in, required spectrum	The spectrum data container to use to get the necessary header information.
freqs in, required	The frequencies to convert (MHz), may be an array of values.

Keywords
frame in, optional string	The rest frame that the frequencies are in. Known rest frames are listed in freqtovel. Defaults to the frame given in the data container.
rel in, optional boolean	If set, the frequencies are relative to the reference channel.
true_frame out, optional string	The actual rest frame used in converting the frequencies. The only way this will not equal the frame argument is if that argument was invalid. In that case, this keyword will be the same as the frame in data.frequency_type.