MGH_INTERPOLATE Name
MGH_INTERPOLATE Purpose
This function is a wrapper for the standard IDL INTERPOLATE
function. It corrects for the anomalous way INTERPOLATE
handles locations near the upper end of the input array, described
by the IDL documentation as follows:
Note - INTERPOLATE considers location points with values between
zero and n, where n is the number of values in the input array
P, to be valid. Location points outside this range are
considered missing data. Location points x in the range
n-1 <= x < n return the last data value in the array P.
Note the final sentence. It is much more logical to treat points
in the range n-1 < x < n as missing, and this is what
MGH_INTERPOLATE does. Note also that the anomalous behaviour
described in the paragraph above is actually done only in the case
of linear interpolation, whereas bilinear interpolation acts in
the way I consider logical.
Calling Sequence
result = MGH_INTERPOLATE(p, x)
result = MGH_INTERPOLATE(p, x, y)
result = MGH_INTERPOLATE(p, x, y, z)
Parameters
See documentation for INTERPOLATE.
Return Value
The function returns a single or double precision floating point array
with size & shape determined by the x, y & z parameters and the GRID keyword.
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This software is provided subject to the following conditions:
1. NIWA makes no representations or warranties regarding the
accuracy of the software, the use to which the software may
be put or the results to be obtained from the use of the
software. Accordingly NIWA accepts no liability for any loss
or damage (whether direct of indirect) incurred by any person
through the use of or reliance on the software.
2. NIWA is to be acknowledged as the original author of the
software where the software is used or presented in any form.
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Modification History
Mark Hadfield, 2002-06:
Written.