Solving system of equations

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Rasto
Rasto on 24 Mar 2013
Hello,
How to solve this task, where to calculate xE1, xE2, yE1, yE2?
Thanks in advance for any advice.
clear all; clc; close all;
CE=5; xC=1; yC=2; xD=3; yD=4;
eqnE1='CE^2=(xC-xEsol)^2+(yEsol-yC)^2';
eqnE2='(yEsol-yC)/(xC-xEsol)=(yC-yD)/(xD-xC)';
solE=solve(eqnE1, eqnE2, 'xEsol, yEsol');
xxE=eval(solE.xEsol);
yyE=eval(solE.yEsol);
xE1=xxE(1);
xE2=xxE(2);
yE1=yyE(1);
yE2=yyE(2);

Accepted Answer

Walter Roberson
Walter Roberson on 24 Mar 2013
When you use
eqnE1='CE^2=(xC-xEsol)^2+(yEsol-yC)^2';
then you are creating a string. The existing values CE and so on are not going to be substituted into that string.
You should not eval() a symbolic result, as symbolic results are not in MATLAB syntax. If you want to import values from the workspace (such as CE) then you should use subs(), possibly followed by double().
  2 Comments
Rasto
Rasto on 24 Mar 2013
Thank you for your answer, but I do not know how to think. Can I please give you the example?
Walter Roberson
Walter Roberson on 24 Mar 2013
solE=solve(subs(eqnE1), subs(eqnE2), 'xEsol, yEsol');
xxE = double(solE.xEsol);

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