The equationsToMatrix MATLAB function receives a linear system of equations and produces the coefficient matrix and the dependent variable. In one equation a variable (represented a symbolic variable) can be repeated and randomly distributed. This MATLAB function was introduced in the year 2012.
There is no directly function to get coeff matrix.But you can split your string from commas.After,you can process it different library.There is a library which is developed by Vera Maghuza .It can parse mathematical expressions. I think it fills your bill.If there will be a lacking function , you can contact developer and want to add the function which you need.Maybe she can add.
http://axiacore.com/blog/mathematical-expression-evaluator-python/
dear dr moreles
Is there an easy way to check if a vector valued symbolic function is linear? If so, is there an easy way to represent this expression in the form A*x, where A is a symbolic matrix and x is the argument (i.e. is there a way to "extract" A given x and A*x)? For the sake of the argument assume that MATLAB symbolic toolbox is being used (although solutions using mupad are also welcome).
syms x1 x2 a b c;
fx1 = [a*(x1+x2); b*x1+c*x1];
fx2 = [a*x1/log(x2); x2^2];
A=checklinearity(fx1, [x1 x2]') % should return [a, a; b+c, 0]
A=checklinearity(fx2, [x1 x2]') % should return false
I was thinking about some direct method that uses string processing to do the following
expand the vector expression using MATLAB's expand() function (the idea is that if it is a linear function each addend will be of the form z(p)*x_i, where z(p) will be a function of parameters and x_i will be an element of the argument vector)
for each element of the vector expression extract individual addends
divide each individual addend by each of the elements of the argument vector and see if the resulting expression does not contain any elements of the argument vector (the latter can be done using MATLAB's symvar() function)
if for each addend one can find the element of the argument vector such as the one described in the previous clause, then the expression should be linear. It should also be possible to construct the matrix A from the coefficients obtain as the result of the divisions.
I think the algorithm above should get me to the solution, but I can see it being slow and bulky... However, the problem itself seems to be very basic
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