[issm-support] Issues with meshing..

[Larour, Eric (385J)]

Dear Derrick, 

I think the issue is that when you plotted your surface velocities in
matlab (before calling exptool
on it), you did not specify the x and y coordinates of your image.

Typically, in matlab, one does:

imagesc(velocity) where velocity is a matrix. This will get you
coordinates in scene coordinates.

For your example, what you need to do is:
imagesc(x,y,velocity),
where x=0:(xmax-xmin)/m:xmax and
      y=0:(ymax-ymin)/n:ymax

and m,n is the size of the velocity matrix.

If you do this, you will recover from exptools the true vertex
coordinates. 

Tell me how it goes!

Thanks! 
Eric L.



On 12/28/12 11:58 PM, "Derrick Lampkin" <djl22 at psu.edu> wrote:

>Greetings,
>
>I recently attended the ISSM workshop and found it useful. I'm attempting
>to use the system to model a system in the Jakobshavn outlet basin. I
>have been using your Jakobshavn example as a template. The exception is
>I'm using a base of surface velocity data derived from NSIDC (Joughin
>data set). I have imported a surface velocity grid as GEOTIFF into matlab
>and I use the exptool to draw the outline of my domain on top of this
>base map. The map is in the polar stereo graphic projection but when I
>create the initial mesh using triangle at the nominal resolution of the
>data (500 m), the grid spacing was not nearly as dense as expected. I
>inspected the domain file I created and the vertices coordinates are in
>scene coordinates (row/column) values and not the projected coordinates ,
>therefore the mesh spacing are not reasonable and do not correspond to
>the specified resolution I indicate in the triangle command. How might I
>fix this issue?
>
>Thanks
>
>derrick j lampkin
>__________________
>research professor
>
>                institute of arctic and alpine research
>         
>                university of colorado-boulder
>
>                   __________________
>
>email: djl22 at psu.edu
>
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