mismatch between docs and reality

[jedwards4b]

In the docs the description of compmap is
a 0 based array of offsets into the array record on file. A -1 in this array indicates a value which should not be transferred.
(in fortran it's a 1 based array and a 0 in the array)

but in reality in pio2.5.9 if there is a 0 in the compmap then the value returned in that location is 0. I'm not yet sure whether I will fix the code or the documentation.