## LINCOEFFS: Matrix coefficients of symbolic linear equations

Version 1.0 (23.9 KB) by
This function extracts the coefficient matrix and the column vector containing the non-homogeneous terms of a system of linear equations.

Updated 11 Apr 2023

From GitHub

# lincoeffs

MATLAB code to extract the coefficients of symbolic linear equations.

This function extracts the coefficient matrix and the column vector containing the non-homogeneous terms of a system of linear equations.

## Syntax

`[A,b] = lincoeffs(equations,variables)`, where `equations` is a column vector of symbolic equations containing left and right sides separated by the `==` operator, and `variables` is a column vector containing symbolic variables. The output arguments, `A` and `b`, allow us to rewrite the equations in the matrix form `A*x==b`.

## Examples

```syms m n
[A,b] = lincoeffs([3*m+10*n==0;m-n==4],[m,n])
rref([A,b])  % reduced row echelon form (Gauss-Jordan)

syms x [3,1]
equations = [5*x(1)-2*x(2)+x(3)==7
x(1)+x(2)+x(3)==0
2*x(1)+8*x(2)-x(3)==6];
[A,b] = lincoeffs(equations,x)
x = A\b   % solve the matrix equation
A*x == b  % test the solution```

## Requires

Symbolic Math Toolbox

``````===================================================================
-------------------------------------------------------------------
<I. Santos-Ruiz> wrote this file. As long as you retain this notice
you can do whatever you want with this stuff.
If we meet some day, and you think this stuff is worth it,
you can buy me a beer in return.
===================================================================
`````` ### Cite As

ILDEBERTO DE LOS SANTOS RUIZ (2023). LINCOEFFS: Matrix coefficients of symbolic linear equations (https://github.com/isantosruiz/lincoeffs/releases/tag/1.0), GitHub. Retrieved .

##### MATLAB Release Compatibility
Created with R2023a
Compatible with any release
##### Platform Compatibility
Windows macOS Linux