Dear All
I have an "interesting" situation.
I generate 2 mutually perpendicular in plane vectors from the horizontal
part of a 3D tensor. Rotate these about an angle to give their
orientation and then want to colour them by magnitude. i.e. all the
vectors with the largest magnitude are the same colour. I couldn't work
out how to separately colour the 2 vectors given when passing a 2D
tensor to glyph so I'm doing it "long hand".
When I pass the vectors directly to my colour/glyphing macro I get
correctly orientated mutually perpendicular vectors but, obviously,
these are not sorted by magnitude. i.e. some times the smaller vector is
coloured as the largest and visa-versa
To overcome this, I passed the vectors through a compute with the
following expression:
mag(Vec1) >= mag(Vec2) ? Vec2 : Vec1
(*.net snippet at end of mail)
Which I hoped would sort them by magnitude and pass the vectors
unchanged. Unfortunately, the vectors returned by this compute are
correctly classified (i.e. bigger vectors are now always coloured as
such), but now the glyphs generated are not always mutually
perpendicular. Clearly, even though the compute is told just to pass the
appropriate vector unchanged it changes the magnitudes somehow.
I have tried specifying everything as doubles, and separating the
vectors into components, sorting then rebuilding them. Neither
approaches help.
Any ideas?
Peter
Ps,
for those in the geological field, this is for visualisation of SH/Sh
from a general 3D stress state calculated in FEM. The *.net application
this routine is part of will soon become available on the
www.World-Stress-Map.org site
Start code snippet
//
// time: Sun Feb 01 14:51:34 2004
//
// version: 3.2.0 (format), 4.3.0 (DX)
//
//
// MODULE main
// workspace: width = 394, height = 476
// layout: snap = 0, width = 50, height = 50, align = NN
//
macro main(
) -> (
) {
//
// node Receiver[1]: x = 141, y = 107, inputs = 1, label = Vec1
//
main_Receiver_1_out_1[cache: 0] = Vec1;
//
// node Receiver[2]: x = 218, y = 110, inputs = 1, label = Vec2
//
main_Receiver_2_out_1[cache: 0] = Vec2;
//
// node Compute[738]: x = 226, y = 272, inputs = 3, label = Compute
// input[1]: defaulting = 0, visible = 0, type = 32, value =
"mag($0) >= mag($1) ? $0 : $1"
// expression: value = mag(Vec1) >= mag(Vec2) ? Vec1 : Vec2
// name[2]: value = Vec1
// name[3]: value = Vec2
//
main_Compute_738_out_1 =
Compute(
main_Compute_738_in_1,
main_Receiver_1_out_1,
main_Receiver_2_out_1
) [instance: 738, cache: 1];
//
// node Compute[739]: x = 322, y = 271, inputs = 3, label = Compute
// input[1]: defaulting = 0, visible = 0, type = 32, value =
"mag($0) >= mag($1) ? $1 : $0"
// expression: value = mag(Vec1) >= mag(Vec2) ? Vec2 : Vec1
// name[2]: value = Vec1
// name[3]: value = Vec2
//
main_Compute_739_out_1 =
Compute(
main_Compute_739_in_1,
main_Receiver_1_out_1,
main_Receiver_2_out_1
) [instance: 739, cache: 1];
//
// node Transmitter[1]: x = 187, y = 414, inputs = 1, label = MaxVec
//
MaxVec = main_Compute_738_out_1;
//
// node Transmitter[2]: x = 336, y = 407, inputs = 1, label = MinVec
//
MinVec = main_Compute_739_out_1;
// network: end of macro body
}
main_Receiver_1_in_1 = NULL;
main_Receiver_1_out_1 = NULL;
main_Receiver_2_in_1 = NULL;
main_Receiver_2_out_1 = NULL;
main_Compute_738_in_1 = "mag($0) >= mag($1) ? $0 : $1";
main_Compute_738_out_1 = NULL;
main_Compute_739_in_1 = "mag($0) >= mag($1) ? $1 : $0";
main_Compute_739_out_1 = NULL;
Executive("product version 4 3 0");
$sync
main();
End code snippet
_____________________________________
Dr Peter Connolly
World Stress Map
@ Geophysical Institute
University of Karlsruhe
Hertzstrasse 16
76185 Karlsruhe
Germany
tel +49 (0)721 6084593
fax +49 (0)721 71173
[EMAIL PROTECTED]
http:\\www.world-stress-map.org
