If that helps, in my CFD data, I almost allways use
"showboundary->Autocolor ...". Then colormap includes only the range
of what you see. Additionally you can do:
"...->showboundary->statistics.." if you want to get min max of the
values. If module showboundary doesn't work properly check your data
structure (for example do not doublicate nodes etc).
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Jonathan Matheson wrote:
I can get a good image that way but I am looking for a way to do this
automatically. I am using it for a computational fluid dynamics
simulation so the pressure range is always different depending on the
shape and other parameters. Also, my cfd program calls dx once it
writes the dx files so the user can immediately see the image. Because
the pressure range depends on the individual problem you'd have to
specify the range each time which is not very practical. My range is
so big now that the good data (data outside the shape surface) appears
all one colour because it occupies a very small range of the
colourmap. If I use 'statistics' to find the max and min it gives me
the garbage values from within the shape. I need to somehow use the
boundary of the shape dx file to exclude the data inside of it and
then search for the max and min outside. I can't find a way to split
up the 'data' or get rid of part of it. I can exclude all of it easily
enough but that's certainly no help.
Thanks,
Jon
Chris Pelkie wrote:
Using only the Colormap Editor (once you install Colormap and a
Color, double-click the Colormap module), you can modify the normally
linear colormap to any shape you want. You can also type in min and
max values right there to constrain what gets colored (it invalidates
the data outside your range, just like Include). So you can pretty
quickly trim outliers, or leave them in, but by adding new control
points, make a colormap that pushes all the colors down and up to
wrap around the 'good' data.
Note the 'histogram' function of Colormap Editor can help identify
where the 'good' data is.
To see all the above, you have to run the data flow from your
imported field into the 1st input of Colormap. Also run this same
output to the 1st input of Color. Then run the 1st output of Colormap
to 2nd input of Color. Samples show this clearly.
On Aug 9, 2005, at 9:47 PM, Jonathan Matheson wrote:
I am importing 2 3D dx files into my .net program. One of them
contains pressure values in the ‘data’ field. The other shape file
has only ‘positions’ and triangular ‘connections’ fields with no
data. The pressure values within the shape are garbage and I need
to make my program ignore them. The problem is that outside of the
shape the pressures are all pretty close but inside they are
really high and really low. As a result of this my colour map does
not show the pressure differences outside the shape. I can
manually set the max and min values through the ‘include’ function
but dx is automatically called from another program and that is
not an option. I am looking for a way to search for the max and
min pressure values while ignoring those that are inside the
shape. If I could do that I can set those values in the ‘include’
function and everything will display properly.
Thanks,
Jon
_______________________________
Chris Pelkie
Scientific Visualization Producer
622 Rhodes Hall, Cornell Theory Center
Ithaca, NY 14853 (607) 254-8794