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ANALYSE\RESAMPLE Nx Xref Xval Xinc Unit [Shape] [Width] [/[NO]FFT]
ANALYSE\RESAMPLE /LIKE GDFFile [/FFT]
This command resamples a given spectrum on a specified X axis in given
unit. The arguments are:
Nx the number of channels desired,
Xref the new reference channel,
Xval the value at the reference channel. Changing the reference fre-
quency or velocity has non trivial effects on the axis. Use '='
when possible (see below), else change the value with caution,
Xinc the new channel separation. In case of FREQUENCY resampling, the
resolution is expected to be given in the restf frame. However,
RESAMPLE does not modify the current frame of the spectrum (i.e.
the Doppler factor is left unchanged), so the input frequency
resolution will be corrected to the current frame.
Unit either VELOCITY or FREQUENCY to indicate the units used for Xval
Shape (optional) a keyword for the frequency response of the synthe-
sized channels (see subtopic for details). By default the shape
of the output channels is the same as the shape of the input
Width (optional) the width of the output channels in units of the
channel separation. The default (and minimum value) is 1.
Using an equal sign '=' for any of these arguments indicates to use the
same value as before. Using a wildcard '*' will choose an automatic de-
Nx is set such as the last input and output channels are aligned,
Xref is set such as the first input and output channels are aligned,
Xval the reference frequency and velocity are left unchanged (same as
Xinc same as =
Shape same as =
Width same as =
/NOFFT is the default behavior. In this case, the output spectrum is a
subset of the original one if their axes are aligned to a given preci-
sion. If not, the spectrum is resampled by direct interpolation. In this
mode the exact channel separation requested will be used. The counter-
part to this technique is that correlation is introduced between adja-
cent channels and thus affects the noise intensity (e.g. it is divided
by sqrt(2) if the axis is shifted by half a channel).
The Width parameter is used to provide an oversampled output spectrum if