Error "Subscripted assignment dimension mismatch" using parfor

Hi

I want to use parfor to derive large symbolic matrices as presented below:

Stiffness = sym('K',[PP PP]);     Inertia = sym('M',[PP PP]);
parfor m=1:PP
    KK = simplify(diff(Strain_Energy/g^2,P(m)));
    MM = simplify(diff(Kinetic_Energy/(omega^2*g^2),P(m)));
    stiffness = sym('K',[1 PP]);
    inertia = sym('M',[1 PP]);
    for n=1:PP
        [KKq,KKr] = quorem(KK,P(n),P(n));
        stiffness(m,n) = KKq;
        [MMq,MMr] = quorem(MM,P(n),P(n));
        inertia(m,n) = MMq;
    end
    Stiffness(m,:) = stiffness;
    Inertia(m,:) = inertia;
end

I receive the error:

"""""""""""""""""""""""""""""""""""""""""""

Error using sym/privsubsasgn (line 1067)

Subscripted assignment dimension mismatch.

Error in sym/subsasgn (line 904)

C = privsubsasgn(L,R,inds{:});

Error in HSDT_Linear (line 116)

parfor m=1:PP

""""""""""""""""""""""""""""""""""""""""""""

I tried to tailor the content of the parfor loop according to the requirements described by the documentation but still this error exists.

Can someone help please?

[darova]

Can you show more code?

[Mo]

P is a vector of unknowns that are used for differentiation in the parfor loop and PP is the length of P, i.e. the total number of unknowns. The parfor loop actually extracts the coefficients of each unknown parameter P(n) existing in the derivative of the two parameters (here called Strain_Energy and Kinetic_Energy) with respect to P(m).

The code works without parfor but takes a long time. The issue is only with parfor in this stage.

[KALYAN ACHARJYA]

Strain_Energy?

[Mo]

That's a symbolic parameter already calculated in the code.

[Mo]

This is the P for example:

P = [U11 U12 U21 U22 V11 V12 V21 V22 W11 W12 W21 W22];

What the loop does is to differentiate Strain_Energy with respect to U11 for example and then extracts the coefficients of the other elements of P such as U12, U22, etc and assigns them in the corresponding element of the output matrix, which is called "Stiffness".

[darova]

I think something is missing. What is PP?

[Mo]

PP is the length of P

[darova]

Is it possible something more?