LabVIEW

cancel
Showing results for 
Search instead for 
Did you mean: 

About the Nonlinear System Solver

Hi, I am trying to solve a nonlinear system that is a little complicated to get the solution manually:

B*Sin(P)/(2*sin(B)*b)=0
B*Sin(W)/(2*sin(A)*b)=0
A+B+P+W-180=0

I tried to use the Nonlinear System Solver entering the formulas and all I get is an error code -23001 (Error -23001 occurred at an unidentified location Possible reason(s):
Analysis:  Syntax error of parser. "
I don't know what I am doing wrong, I am doing it similarly to the attached VI, with my own equations and controls. I even tried to change the equations so I would delete the "sin" (sine), just to make a test (about syntax and the solver not understanding that command?), and I got the same error.

Help is much appreciated,
Thanks
0 Kudos
Message 1 of 13
(4,437 Views)
I'm sorry, this is the VI.
0 Kudos
Message 2 of 13
(4,424 Views)
You have only 3 equations, but more than 3 parameters.
 
Most likely there will be an infinite number of solutions. Are you sure this is solvable?

Message Edited by altenbach on 10-27-2005 11:20 PM

0 Kudos
Message 3 of 13
(4,422 Views)
Yes, I'm sorry, I forgot to say which ones were the known variables, these are A and B.
So there are 3 equations, and 3 unknown variables (b, W and P) Smiley Happy
0 Kudos
Message 4 of 13
(4,409 Views)
I got it to work by modifying the "Equation Explorer Example" in the example finder. What are typical values for A and B?
0 Kudos
Message 5 of 13
(4,397 Views)
I fixed some things in my calculus and the actual system is:

B*Sin(P)/(2*sin(Beta)*b)=0
B*Sin(W)/(2*sin(A)*b)=0
A+B+P+W-180=0

Beta is known too.
B is a still value of 82.
0<A<90, 0<Beta<90

May I know how did you make it work? The values range is not so much of an important thing, I want to get rid of that error! hehe.
The system is to solve the X-Y position of a robot in a board using IR signals.
Thanks.
0 Kudos
Message 6 of 13
(4,392 Views)
Oh god, the error was a CAPS letter Smiley Mad. I had sin(A) instead of sin(a) so that would give me formula error. I found this in the error codes examples. I think its just stupid that the program would give me an error because of that.
Anyways, I'm not getting any error anymore, but the solutions are always zero, Do I have to set up something else except the start - end parameters?
0 Kudos
Message 7 of 13
(4,390 Views)
Also remember that the argument to trigonometric functions must be in radians here.
 
Are you sure that A and Beta are not [0<A<π/2], [0<Beta<π/2].
How about the "180" in the last formula. Shouldn't it be π instead?
Is b 83 degrees or just a constant of 82?
0 Kudos
Message 8 of 13
(4,383 Views)
"B" (caps) is just a constant of 82, "b" is unknown, and could range between 0 and 100 aprox.
I have the 180 and the A and Beta range in radians too. But I keep getting just nothing as the zeroes of my system Smiley Sad

Message Edited by MiGSPiNe on 10-29-2005 04:42 PM

0 Kudos
Message 9 of 13
(4,378 Views)

Well, my version has no problem finding solutions, however they are all trivial:

Just make b larger than e.g. 10^9 and find a combination of p and w that satisfies equation 3 and everything is zero (within the desired resolution).

Somehow, I believe that your formula is still not right. Do you have a link to a website that describes the math behind it?

0 Kudos
Message 10 of 13
(4,367 Views)