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Re: [ferret_users] contours, hlimits=, x=, ?

Hi Ryo,
So, what you did at the end of your script SHOULD have worked, specifying a larger region than desired with the /X= and /Y= qualifiers to fill to the edges of the /HLIMITS/VLIMITS region. But the fill doesn't extend to the edges in Y.

yes? fill/hlimits=10:30/vlimits=80s:60s/x=9:31/y=81s:59s rose

We'll look into why this happens. But notice that the following command does give you th plot, completely filled in to the edges:

yes? fill/x=10:30/y=80s:60s rose


Steve Hankin wrote:

Hi Ryo,

X= specifies the data range
HLIMITS= specifies the clipping region of the plot axes

The etopo20 dataset is defined on a longitude axis that runs from 20 to 380, so that its "branch point" does not disect a major ocean basin. (Try "SHOW GRID rose") Your graphical axis limits "hlimits=10:30" span this branch cut. Since your FILL command does not specify the coordinate range explicitly (no "/X=" is specified) the Ferret IO layer supplies to the graphics layer the full native coordinate range, which is X=21:379. Thus your specified axis range of 10:30 overlaps the data for only half of its range, 21:30. So half of your plot is blank.

- steve

Ryo Furue wrote:

Hi Ferret users and developers,

I reported a similar problem a while ago, but now things
are looking "curiouser and curiouser". Basically, I'm wondering
what happens and what should happen when hlimits= (vlimits=) is
specified for a contour plot.

Here's little experiment I've done:


First, when I don't specify x= or y=,

yes? set data etopo120
yes? fill/lev=(-6000,4000,1000,-1)/hlimits=10:30/vlimits=80s:60s \

I get a huge white region, as seen in the plot in my webpage cited
above. Is this just me? or does this happen to other users?

Next, when I specify both hlimits (vlimits) and x= (y=),

yes? fill/. . ./hlimits=10:30/vlimits=80s:60s \
/x=10:30/y=80s:60s rose

I get a clean plot.

The plot isn't quite satisfactory, though, because there is a white
region along the edges (and I think I know why).
Since we have datapoints outside our plotting region,
why not use them?

yes? fill/. . ./hlimits=10:30/vlimits=80s:60s \
/x=9:31/y=81s:59s rose

But, this plan partially fails. When we extend only in the y-direction
(y=81s:59s), the contouring region is extended to the northern and southern edges. Good. But, when we extend in the
x-direction (x=9:31), we get a weired plot, as shown in my webpage.

Maybe am I doing something which shouldn't work?


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