Solvers accept matrix initial point
matrix means an array of any size. They also accept matrix bounds
Here's how solvers handle matrix arguments.
Internally, solvers convert matrix arguments into
vectors before processing. For example,
For an explanation of this syntax, see the
For output, solvers reshape the solution
the same size as the input
x0 is a matrix, solvers pass
a matrix of the same size as
x0 to both the objective
function and to any nonlinear constraint function.
Linear constraints, though,
x in vector form,
In other words, a linear constraint of the form
A*x ≤ b or
x as a vector, not a matrix. Ensure
that your matrix
the same number of columns as
x0 has elements,
or the solver will error.