Rich,
> I'm having minor problems rotating my plot using the MAPROJ routine.
> I set XC1 at -180. and XCM at 180. for vector plots, but would like
> to center the map on an area of interest. I thought I could change
> PLON in MAPROJ, to say 40., instead of 0. The vector field and map
> seems to rotate correctly, but I see two columns of vectors closer
> together than the other columns. As I rotate the map, the those two
> columns move and are quite noticable. I assume these are the columns
> at -180 and 180 when PLON is 0.
>
> Am I explaining this correctly? Can I rotate the map this way?
>
> The same thing happens when I contour, I get a small 'jag' in the
> contours that rotates.
In the data array that you're contouring from (call it ZDAT, dimensioned
M x N), is it the case that, for all J from 1 to N, ZDAT(1,J) = ZDAT(M,J)?
If not, then you will see the effect that you describe. CONPACK doesn't
know that your data array is to be treated cyclically in the first subscript;
for each horizontal row of grid boxes, it generates contours in the grid box
defined by I=1 and I=2, in the grid box defined by I=2 and I=3, and so on,
up to I=M-1 and I=M; it won't generate any lines for the "box" defined by
I=M and I=1. So, for example, to represent a field to be contoured on a
1-degree grid around the globe, you have to dimension the array 361 x 181.
Dave Kennison
This archive was generated by hypermail 2b29 : Wed Jun 28 2000 - 09:40:34 MDT