Array indices must be positive integers or logical values.

A = [1 2 3; -4 1 2; 0 9 -8];
B = [12; 13; -1];

solution = A\B

solution = 3×1

-1.2424 2.3939 2.8182

det = det(A)

det = -198

Can anyone tell me why i keep getting error?

Array indices must be positive integers or logical values.

det = det(A)

Answer 1

[Torsten]

I don't get this error message (see above). But you should rename the result from det(A) - otherwise you have "overwritten" the built-in MATLAB function "det" with the numerical value -198.

[Luloah Albanay]

It used to work before but I am not sure why I keep getting this error now and I did rename it but doesn't seem to work

[Steven Lord]

You will not be able to call the det function while a variable named det is in your workspace. Renaming the variable in your code will not rename the variable that was created in the workspace by a previous run of your code. Change your code, clear the variable, then run the updated code.

Answer 2

[Luca Ferro]

You cannot name a variable with the same name as a built-in matlab function.

Change the line det=det(A) to something else like detA=det(A).

[Luloah Albanay]

I have tried that but doesn't seem to work

[John D'Errico]

@Luloah Albanay

If you tried it, and it did not work, then you still have a variable named det in your workspace!

Just changing the line where you created det as a variable will not help, if you will then re-run this script without deleting the variable you just named det.

[Luca Ferro]

exactly. use this before rerunning the script.

clear det

i would not use clear all since there may be variables you want to keep in the workspace.

Answer 3

[Image Analyst]

Type

clear all;

to get rid of your "det" that you created previously, and then run your code either in a script or the command window.

clear all;
A = [1 2 3; -4 1 2; 0 9 -8];
B = [12; 13; -1];
solution = A\B
detA = det(A)