The logical indices contain a true value outside of the array bounds

I am trying to test the following conditions:

if intabsul == absintul && intabsur==absintur

returns the corresponding entries of the xivals and Lvals

elseif intabsul ~= absintul && intabsur~= absintur

return the corresponding entries of the xivals and Lvals

elseif intabsul == absintul && intabsur~=absintur

return the corresponding entries of the xivals and Lvals

elseif intabsul ~= absintul && intabsur==absintur

return the corresponding entries of the xivals and Lvals

else do nothing.

Here is my code:

xivals = linspace(0, 10, 10);

Lvals = linspace(2e-8, 666.7e-6, 5);

for il=1:length(Lvals);

for ixi=1:length(xivals)

%

intul(ixi, il) = trapz(yvals, uxl(:, ixi, il));

intabsul(ixi, il) = trapz(yvals, abs(uxl(:, ixi, il)));

%

intur(ixi, il) = trapz(yvals, uxr(:, ixi, il));

intabsur(ixi,il) = trapz(yvals, abs(uxr(:, ixi, il)));

%

absintul(ixi, il) = abs(trapz(yvals, uxl(:, ixi, il)));

%

absintur(ixi,il) = abs(trapz(yvals, uxr(:, ixi, il)));

end

end

And I tried:

mask1 = intabsul == absintul & intabsur == absintur;

subset_xi_1 = xivals(mask1);

subset_Lv_1 = Lvals(mask1);

But I received an error: "subset_xi_1 = xivals(mask1);

"The logical indices contain a true value outside of the array bounds".

This error is because the entries in "mask1" are not all true "1" or false "0".

It seems mask1 have to be all '1' or '0' for it to work.

Is any where to tackle this problem using "if" statement instead using this approach?

I want corresponding xivals and Lvals if: intabsul == absintul & intabsur == absintur or

intabsul - absintul< epsilon & intabsur -absintur < epsilon, where epsilon =1e-12

Answer 1

[Fangjun Jiang]

No. The problem is about the size mis-match

a=1:3;
index=[true false true true];
a(index)

The logical indices contain a true value outside of the array bounds.

In your case, you are doing logical indexing so check the value of size(mask1) and size(xivals). They need to be same to guarantee no error like above.

[Fangjun Jiang]

It is strange that this case does not generate error due to size mis-match. I guess that is why the message says "a true value outside of the array bounds"

a=1:3;
index=[true false true false];
a(index)

ans = 1×2

1 3

[University]

Thank you for your help but the size of size(mask1) and size(xivals) depends on the sizes of intabsul, absintul, intabsur and absintur. How can I match the size since picking values directly from these integrals?

[Fangjun Jiang]

You have to figure it out yourself. There are no size info or values for those variables provided. The code can't be run.

[University]

Hi Fangjun. I have attached the data.

%

load('sol_active_flow_varinying_xiL.mat')

xi=xivals;

L =Lvals;

intabsul = intabsul;

intabsur =intabsur;

absintul =absintul;

absintur =absintur;

%% This is where I having an issue

test1 = intabsul == absintul & intabsur == absintur;

subset_xi_1 = xivals(test1);

subset_Lv_1 = Lvals(test1);

test2 = intabsul ~= absintul & intabsur ~= absintur;

subset_xi_2 = xivals(test2);

subset_Lv_2 = Lvals(test2);

%

test3 = intabsul ==absintul & intabsur ~= absintur;

subset_xi_3 = xivals(test3);

subset_Lv_3 = Lvals(test3);

%

test4 = intabsul ~= absintul & intabsur == absintur;

subset_xi_4 = xivals(test4);

subset_Lv_4 = Lvals(test4);