i want to run parfor loop.... but there is a problem like slice... help me.....

    parfor i=1:Num

        alpha_i2_1 = alpha(i+2,1);
        alpha_i1_1 = alpha(i+1,1);
        alpha_i_1 = alpha(i,1);

        B(2*i-1:2*i,6*i-5:6*i) = [...
            1+0.5*Time*A0_5_1+0.5*Time*A0_6_1*alpha_i2_1, ...
            -2+Time^2*A0_1_1+Time^2*A0_2_1*alpha_i1_1,...
            1+0.5*Time*A0_6_1*-alpha_i_1-0.5*Time*A0_5_1, ...
            0.5*Time*A0_6_1*-alpha_i2_1, ...
            Time^2*A0_2_1*-alpha_i1_1, ...
            0.5*Time*A0_6_1*alpha_i_1; ...
            alpha_i2_1+0.5*Time*A0_7_1+0.5*Time*A0_8_1*alpha_i2_1, ...
            -2*alpha_i1_1 + Time^2*A0_7_1+Time^2*A0_8_1*alpha_i1_1, ...
            alpha_i_1-0.5*Time*A0_8_1-0.5*Time*A0_7_1, ...
            -alpha_i2_1+0.5*Time*A0_8_1*-alpha_i2_1, ...
            2*alpha_i1_1+Time^2*A0_4_1*-alpha_i1_1, ...
            -alpha_i_1+0.5*Time*A0_8_1*alpha_i_1] ;
    end

They indicate that Valid indices for 'B' are restricted in PARFOR loops. and The PARFOR loop cannot run due to the way variable 'B' is used.

please, help me. give me a advice

Answer 1

[Edric Ellis]

You're trying to write the results of your PARFOR loop into 'B'. The rules for doing this mean that you can only index 'B' with the loop variable 'i', and other constant expressions. For example, the following is valid:

parfor i = 1:10
   B(i, 7) = 2 * i;
end

but the following is not:

parfor i = 1:10
    B(2 * i:(2 * i + 1)) = i;
end

You need to simplify your expression so that your calculation results in values you can store in this form. Usually it's best in this sort of situation to try and calculate a whole row or column, something like

B = zeros(10, 10);
parfor i = 1:10
  B(:, i) = rand(10, 1) * i;
end

and then reshape 'B' after the loop.