[A,b] =
equationsToMatrix(eqns)
converts equations eqns to matrix form. eqns must
be a linear system of equations in all variables that symvar finds in
eqns.

Convert a system of linear equations to matrix form.
equationsToMatrix automatically detects the variables in the
equations by using symvar. The returned coefficient matrix follows
the variable order determined by symvar.

syms x y z
eqns = [x+y-2*z == 0,
x+y+z == 1,
2*y-z == -5];
[A,b] = equationsToMatrix(eqns)
vars = symvar(eqns)

A =
[ 1, 1, -2]
[ 1, 1, 1]
[ 0, 2, -1]
b =
0
1
-5
vars =
[ x, y, z]

You can change the arrangement of the coefficient matrix by specifying other
variable order.

vars = [x, z, y];
[A,b] = equationsToMatrix(eqns,vars)

A =
[ 1, -2, 1]
[ 1, 1, 1]
[ 0, -1, 2]
b =
0
1
-5

Specify Variables in Equations

Convert a linear system of equations to the matrix form by specifying
independent variables. This is useful when the equation are only linear in some
variables.

For this system, specify the variables as [s t] because the
system is not linear in r.

syms r s t
eqns = [s-2*t+r^2 == -1
3*s-t == 10];
vars = [s t];
[A,b] = equationsToMatrix(eqns,vars)

A =
[ 1, -2]
[ 3, -1]
b =
- r^2 - 1
10

Return Only Coefficient Matrix of Equations

Return only the coefficient matrix of the equations by specifying a
single output argument.

syms x y z
eqns = [x+y-2*z == 0,
x+y+z == 1,
2*y-z == -5];
vars = [x y z];
A = equationsToMatrix(eqns,vars)

eqns — Linear equations vector of symbolic equations or expressions

Linear equations, specified as a vector of symbolic equations or expressions.
Symbolic equations are defined by using the == operator, such as
x + y == 1. For symbolic expressions,
equationsToMatrix assumes that the right side is 0.

You can also select a web site from the following list:

How to Get Best Site Performance

Select the China site (in Chinese or English) for best site performance. Other MathWorks country sites are not optimized for visits from your location.