Silent protagonist: Created page with 'Solving a System of Non-Linear Equations: Octave can solve a system of non-linear equations of the form f(x)=0 using the function fsolve fsolve (fcn, x0, options) [x, fvec, i…'

2010-10-04T17:38:58Z

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Solving a System of Non-Linear Equations:
Octave can solve a system of non-linear equations of the form

f(x)=0

using the function fsolve
fsolve (fcn, x0, options)
[x, fvec, info, output, fjac]= fsolve (fcn,... )
Where fcn is a vector containing the system, and x0 is a vector containing initial guesses for each variable (nescessary for this particular algorithm).

To solve the system
<math>−2x^2+3xy+4sin(y)-6=0</math>
<math>3x^2-2xy^2+3cos(x)+4=0</math>

Enter the following:
%define a function for fsolve to use, containing the system
functiony=f(x)
y(1)=-2*x(1)^2+3*x(1)*x(2)+4*sin(x(2))-6;
y(2)=3*x(1)^2-2*x(1)*x(2)^2+3*cos(x(1))+4;
endfunction

%call fsolve, and place the results into a vector
[x,fval,info]=fsolve(@f,[1;2])

See pg 331 in the Octave Manual for more info.

Robert's Octave Assignment - Revision history

Silent protagonist: Created page with 'Solving a System of Non-Linear Equations: Octave can solve a system of non-linear equations of the form f(x)=0 using the function fsolve fsolve (fcn, x0, options) [x, fvec, i…'