[GEMPAK #ISM-524898]: Computing max or min over subset of a grid

Bob,

SGMX and SGMN compute max and min respectively over a subarea. See "phelp 
gfunc":

      The SGMX and SGMN functions return the maximum and minimum, respectively,
      found on the subset of the grid defined by GAREA and PROJ.

Steve Chiswell
Unidata User Support




> Support:
> 
> I am trying to use GARP/GEMPAK to compute the maximum value
> of a scalar (e.g., vertical velocity) over a subset of a grid
> of model output.  All I can find in the Grid Diagnostic Functions
> is 'HIGH' for maximum and 'LOWS' for minimum. The documentation
> says:
> 
> LOWS ( S, RADIUS ) where RADIUS defines a square region of grid points.
> The region is a moving search area in which all points are compared
> to derive a relative minimum.
> 
> Can somebody please explain what this means? Or better yet, can
> you point me to a simple diagnostic function to determine the
> maximum or minimum of a scalar over a subset (preferably over
> a rectangle defined by outlining an area of points in GARP).
> 
> I find it very convenient to use the 'SAVS' function which
> gives me the average of a scalar over a grid defined by the
> area outlined in GARP.  I am hoping there is something similar
> for the maximum or minimum over the same area.
> 
> Bob
> 


Ticket Details
===================
Ticket ID: ISM-524898
Department: Support GEMPAK
Priority: Normal
Status: Closed