The FILL command is an interpolation operation (it has to find a contour path between grid cells). The SHADE command is not (it simply treats each cell independently). Normally Ferret makes a small adjustment in the extent of the plotting region to accomodate the 1/2 grid cell variation that exists between these two methods of rendering the graphics.
To see this difference look at the X axis limits used by the PLOT+ engine ("ppl list xaxis") in this output:
yes? use coads_climatologyFrom what you've described I presume that you are using /OVERLAY or /HLIMITS and thereby (accidentally?) taking control of the extent of the plotting region. The following command illustrates how you can create white space at the edges this way:
yes? shade/x=130e:80w/y=20s:20n/l=1 sst
yes? ppl list xaxis
LO= 1.30E+02 HI= 2.80E+02 TIC= 2.00E+01 LEN= 8.00E+00
yes? fill/x=130e:80w/y=20s:20n/l=1 sst
yes? ppl list xaxis
LO= 1.31E+02 HI= 2.79E+02 TIC= 2.00E+01 LEN= 8.00E+00
yes? fill/x=130e:80w/y=20s:20n/l=1/hlimits=130e:80w sst
Solution: As long as you set the data region ("x=130e:80w" above) to be at least a grid cell larger on each side than the plotting region ("hlimits=130e:80w" above) you can avoid this problem.
Ansley Manke wrote:
Yes, we've seen this. Isyour data on an irregularly spaced
grid? Depending on the data and the grid it's on, the algorithm
that does the fill plot can't always fill the entire region. A
workaround is to do a SHADE plot and then overlay it with
your FILL command, using the same contour levels.
Sang-ki Lee wrote:
> Hi. My problem is that when "fill" command is used for colored contour,
> sometimes I get white space at top or side edge of the colored contour
> plot. This problem come and go, and it is nothing to do with missing
> data point. Has anyone noticed this problem?
> I am using v5.60 on Linux.
> Thank you.
Steve Hankin, NOAA/PMEL -- Steven.C.Hankin@noaa.gov
7600 Sand Point Way NE, Seattle, WA 98115-6349
ph. (206) 526-6080, FAX (206) 526-6744