How can I solve system of linear equations in SymPy?
Sorry, I am pretty new to sympy and python in general.
I want to solve the following underdetermined linear system of equations:
x + y + z = 1
x + y + 2z = 3
Answer
SymPy recently got a new Linear system solver: linsolve in sympy.solvers.solveset, you can use that as follows:
In [38]: from sympy import *
In [39]: from sympy.solvers.solveset import linsolve
In [40]: x, y, z = symbols('x, y, z')
List of Equations Form:
In [41]: linsolve([x + y + z - 1, x + y + 2*z - 3 ], (x, y, z))
Out[41]: {(-y - 1, y, 2)}
Augmented Matrix Form:
In [59]: linsolve(Matrix(([1, 1, 1, 1], [1, 1, 2, 3])), (x, y, z))
Out[59]: {(-y - 1, y, 2)}
A*x = b Form
In [59]: M = Matrix(((1, 1, 1, 1), (1, 1, 2, 3)))
In [60]: system = A, b = M[:, :-1], M[:, -1]
In [61]: linsolve(system, x, y, z)
Out[61]: {(-y - 1, y, 2)}
Note: Order of solution corresponds the order of given symbols.