Hi Derrick,
it sounds like the problem is coming from the output of InterpFromGridToMesh, not from bamg.
bamg complains because the field that is provided (the ice velocity) does not have the right size.
The vector 'field' that is used by bamg should be of length [md.mesh.numberofvertices 1].
You should check that when you do
vx=InterpFromGridToMesh(x1,y1,velx',md.mesh.x,md.mesh.y,0);
size(vx,1) == md.mesh.numberofvertices;
you can also "plot" vx to check that it looks ok:
plotmodel(md,'data',vx);
let us know if it helps.
--
Mathieu Morlighem
On Dec 31, 2012, at 10:53 PM, "Larour, Eric (385J)" <eric.larour at jpl.nasa.gov<mailto: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<mailto: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<mailto: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<mailto: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<mailto:djl22 at psu.edu>
_______________________________________________
issm-support mailing list
issm-support at issm.ess.uci.edu<mailto: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<mailto: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<mailto:issm-support at issm.ess.uci.edu>
http://issm.ess.uci.edu/cgi-bin/mailman/listinfo/issm-support
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://issm.ess.uci.edu/pipermail/issm-support/attachments/20121231/1450adcf/attachment-0001.html>