Problem in solving optimization problem

[Ruchika]

I am trying to solve an optimization problem on python with gurobi solver.
There is a constraint in which I am trying to multiply a 1*n variable vector with a single column of n*n matrix:

The code is as follows:

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sigma1m=np.matrix(sigma1) gamma1=model.addMVar(n, name="gamma1") for i in range(n):      model.addConstr(gamma1*sigma1m[:,i]==0)

In this case, n=22
sigma1 is a 22*22 covariance matrix obtained from some data (sigma1=dfpart1.cov()). gamma1 is a variable vector consisting of 22 elements.

Error:
 TypeError: only size-1 arrays can be converted to Python scalars