Vector plots

["Donald S. Dunbar" <dsd@xxxxxxx>]

The Ferret user's guide is not clear on one point concerning vector
plots.  When the (U,V) components are on different grids (e.g., a
staggered numerical model grid) what does Ferret do?  With U (V) on the
left (bottom) of a cell the command "vector u[k=1],v[k=1]" seems to
generate the same plot as "vector u[g=s,i=1:M,j=1:N,k=1],
v[g=s,i=1:M,j=1:N,k=1]" where s (the salinity) is located at the center
of a cell.  Are the plots the same?  Does Ferret regrid U and V
automatically to locate them at the same point?  And another thing.  Why
do I need to put the "i=1:M,j=1:N" in the brackets (M and N are the No.
or cols and rows)?  If I omit them I get the message:

**ERROR: inconsistent sizes of data regions: X and Y vector components

even though the U and V grids are the same size.  Explicitly putting in
the i and j ranges fixes the problem.
-- 
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D.S. Dunbar (dsd@oar.com)  Ocean Applied Research Ltd.
1864 Duchess Ave.  West Vancouver BC  V7V 1R1  CANADA
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