
as with the gaussian filter.<p>

The fourth form uses a voigt filter. <b>nrise</b> should be half the
value of the point where the transform drops to zero, and
<b>ampnoise</b> should be the value of the transform at this half way
point. These should be determined in the same way as with the
gaussian filter.<p>

The filter commands do change the data, sometimes in rather 
unexpected ways. So it is advisable to examine the results carefully 
to ensure you have exactly what you require.
<p><br>

<h3>Examples<