How to solve for 4 variables from 5 equations that I have derived.
4 views (last 30 days)
Show older comments
Hi, I have a problem in MATLAB. I am doing research in Optics ... I have to find 4 values from 5 equations and having some trouble. Kindly help.
I have tried reg this as below: I would be grateful to have any suggestions. Thanks in advance
clear
T = 0.89; R = 0.11; lamda = 0.98; d = 1.65; pi = 3.14; phit = 0.6; phir = 0.31; %((-(a))*d) == (23.03)*k;
% sym a b n k; % a and b are "alpha" and "beta"
a = sym('a'); b = sym('b'); n = sym('n'); k = sym('k');
eq1 = T == '({(1-R)^2+4*R*(sin(phir))^2}*exp((-a)*d))/((1-R*exp((-a)*d))^2+4*R*exp((-a)*d)*(sin(b+phir))^2)';
eq2 = (phit) == '((2*(pi)*n*d)/lamda)-(atan((k(n^2+k^2-1))/((k^2+n^2)*(2+n)*n)))+(atan((R*exp((-a)*d))*(sin2(b+phir))/(1-R*exp((-a)*d)*cos2(b+phir))))';
eq3 = (phir) == 'atan(((-2)*k)/(1-((n)^2)-((k)^2)))';
eq4 = (b) == '((2*(pi)*n*d)/lamda)';
eq5 = (a) == '((4*(pi)*k)/lamda)';
%eq6 = (e) == '((-(a))*d) == (23.03)*k';
[a b n k] = solve(eq1,eq2,eq3,eq4,eq5,a,b,n,k);
0 Comments
Answers (4)
Azzi Abdelmalek
on 2 Oct 2012
Edited: Azzi Abdelmalek
on 2 Oct 2012
Corrected code
syms a b n k;
eq1 ='T==(((1-R)^2+4*R*(sin(phir))^2)*exp((-a)*d))/((1-R*exp((-a)*d))^2+4*R*exp((-a)*d)*(sin(b+phir))^2)';
eq2 = 'phit==((2*(pi)*n*d)/lamda)-(atan((k(n^2+k^2-1))/((k^2+n^2)*(2+n)*n)))+(atan((R*exp((-a)*d))*(sin2(b+phir))/(1-R*exp((-a)*d)*cos2(b+phir))))';
eq3 = 'phir==atan(((-2)*k)/(1-((n)^2)-((k)^2)))';
eq4 = 'b==((2*(pi)*n*d)/lamda)';
eq5 = 'a==((4*(pi)*k)/lamda)';
sol= solve(eq1,eq2,eq3,eq4,eq5,a,b,n,k)
but it seems that you system does'nt have solutions. Notice that you have more equations then unknown variables
0 Comments
Shaumik
on 4 Oct 2012
4 Comments
Walter Roberson
on 4 Oct 2012
Edited: Walter Roberson
on 4 Oct 2012
What are sin2() and cos2() ? If you want sin-squared you need sin(x)^2
See Also
Categories
Find more on Numbers and Precision in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!