[issm-support] data format conversion question..

djl22 djl22 at psu.edu
Tue Jan 15 21:51:15 PST 2013 

Hi,

I had a small question about data format conversion. I actually have a 
shapefile created in ARCGIS that defines a regions bounded by polygons. 
I know I can get them imported into matlab, but I want to use them in a 
similar way as you did in your Jakobshavn example where you create an 
Argus file to define regions for shear margin softening.
The issue is converting my shapefile into the Argus format without 
retracing the shapefile using exptool (which is possible, the primary 
reservation is that some of my polygon geometry is a bit complex in 
spots), or without having to buy ARGUS ONE personally.

Any ideas?

Thank you very much.
Best

On 12/31/2012 5:18 PM, Larour, Eric (385J) wrote:
> Derrick,
>   
> I ran your example and everything went fine. So the only thing right now
> I can think
> of is that your model is not in sync with svelint (i.e. svelint is not a
> vertex based vector of
> size (md.mesh.numberofvertices,1)). To check on that, could you send me
> the results of the following?
>
>
>>> md.mesh
>>> whos x y svelocity svelint
>
> Thanks!
>
> Eric L.
>
>
>
>
>
> On 12/31/12 1:53 PM, "Larour, Eric (385J)" <eric.larour at jpl.nasa.gov>
> wrote:
>
>> Derrick,
>>
>> I'm also puzzled as to why bang is giving you an error. I am right now
>> working
>> on reproducing the bug from your procedure document. Will keep you posted
>> as soon
>> as I find the bug. Should not be long.
>>
>> For further reference, please include issm-support at issm.ess.uci.edu in
>> your reply
>> all, so other ISSM folks can also help you :)
>>
>> Eric L.
>>
>>
>>
>>
>>
>> On 12/31/12 12:17 AM, "djl22" <djl22 at psu.edu> wrote:
>>
>>> Hi,
>>>
>>> I think I found a way through it. I tried working with the original
>>> data, which provides surface velocity over the entire Greenland ice
>>> sheet projected in polar stereographic. I used geotiffread to import the
>>> GEOTIFF image. I used exptool to draw my domain as a sub-region
>>> (Jakobshavn area) from the imported image and set the initial resolution
>>> of my mesh at 2km (2000m). The output mesh looks about right. I then
>>> extract the pixel center coordinates using the pixcenters command:
>>>>> info=geotiffinfo(filename);From
>>>>> [x,y] = pixcenters(info);
>>> This gets my coordinates for pixel centers. I then have to flip my (y)
>>> coordinates because the InterpFromGridToMesh command complains that the
>>> values should be decreasing. After doing so I run the
>>> InterpFromGridToMesh command and here things get odd. I notice that in
>>> your examples the velx and vely variables in your Searise and jakobshavn
>>> examples are entered in the InterpFromGridToMesh command as the
>>> transpose of these variables, is this correct? (i.e.
>>> vx=InterpFromGridToMesh(x1,y1,velx',md.mesh.x,md.mesh.y,0);).
>>> If I enter my velocity grid as such then I get an error. if I enter
>>> without the transpose the command seems to work, but then I get an odd
>>> message when I use the output from the Interp command in the following
>>> bamg command. I get:
>>>
>>> Anisotropic mesh adaptation
>>> Error message: 'field' should have 930 rowsError using BamgMesher
>>>
>>> At this point I'm lost as to why its not working. When I attempted to
>>> run your Searise example as indicated, I ended up with the same exact
>>> error in running bamg (I ran the lines of code provided directly from
>>> the example). I also go tthis error when I ran the Searise example:
>>> Error message: Input parameter of class single not supported yetError
>>> using InterpFromGridToMesh
>>>
>>>   when I ran
>>> vx=InterpFromGridToMesh(x1,y1,velx',md.mesh.x,md.mesh.y,0);...in this
>>> case I converted the input variables x1, y1 and velx, vely to double
>>> (x1=double(x1), etc...) was this necessary to get it to work? The
>>> command worked after doing this which means ISSM could not recognize the
>>> data type "single" as oppose to "double"
>>>
>>> at any rate, i'm now stuck at bamg where I'm attempting to use the
>>> velocity i assume were interpolated to my initial mesh within my custom
>>> domain to refine my initial mesh which would ideally create finer mesh
>>> grids near the margins of Jakobshavn than outside of the margins....
>>>
>>> Thanks so much for the assistance....
>>>
>>>
>>> On 12/29/2012 3:04 AM, Larour, Eric (385J) wrote:
>>>> 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
>>>>>
>>>>> _______________________________________________
>>>>> issm-support mailing list
>>>>> issm-support at issm.ess.uci.edu
>>>>> http://issm.ess.uci.edu/cgi-bin/mailman/listinfo/issm-support
>>>
>>> -- 
>>> derrick j lampkin
>>> __________________
>>> research professor
>>>
>>>                  institute of arctic and alpine research
>>>                  university of colorado-boulder
>>> adjunct
>>>                    department of geoscience
>>>                    pennsylvania state university
>>>                     __________________
>>>
>>> email: djl22 at psu.edu
>>> web: http://www.geosc.psu.edu/academic-faculty/lampkin-derrick
>>>
>> _______________________________________________
>> issm-support mailing list
>> issm-support at issm.ess.uci.edu
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-- 
derrick j lampkin
__________________
research professor

                 institute of arctic and alpine research
                 university of colorado-boulder
adjunct
                   department of geoscience
                   pennsylvania state university
                    __________________

email: djl22 at psu.edu
web: http://www.geosc.psu.edu/academic-faculty/lampkin-derrick

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