while loop keeps running forever

I'm having trouble with my while loops. when I run the program it keeps going forever. I dont know if why. Can anyone help?

NCJT=2

NSC=zeros(NCJT*NJ,1)

B=1

C=0

D=NDOF

NS=size(MSUP,1)

while B:NJ

Count=0

B1=1

while B1:NS

while ( (MSUP(B1,1)=B) )

Count=1

B2=1

while ( (MSUP(B1,B2+1)=1) )

B3=(B-1)*NCJT+B2

while ( (B2:NCJT) )

D=D+1

NSC(B3)=D

B2=B2+1

endwhile

endwhile

C=C+1

NSC(B3)=C

endwhile

B1=B1+1

endwhile

while ( (Count=0) )

B2=1

while B2:NCJT

B3=(B-1)*NCJT+B2

C=C+1

NSC(B3)=C

B2=B2+1

endwhile

endwhile

B=B+1

endwhile

[Zahrah Walid]

Take care that closing the while loop is by "end" not "endwhile".

[Jonathan Ashley]

it still goes infinite after changing it says repeatedly B3=3

Answer 1

[Zahrah Walid]

First, it's "end" not "endwhile" for closing the loop.

Second, the condition must be logical value; in other words, you should compare using "==" insteade of "=" in line 11 and 13 and edit the others to be valid conditions (logical values).

[Jonathan Ashley]

thank you, Zahrah this is the mistake i was having me being new to matlab coding i didnt know to use "==" this was super helpful

[Zahrah Walid]

You are welcome, Jonathan.

As you are new to MATLAB, I highly recommend you taking MATLAB Onramp course which will give you a suitable base of knowledge to start from. It's free and about 2-hour long only.

Regarding your code, please illustrate its function to debug it.

Answer 2

[John D'Errico]

I think you seriously need to spend some time with the MATLAB tutorials.

1. while is not terminated by endwhile
2. A while loop is not written as: while B:NJ. You probably want to learn what a for loop does instead.
3. You perform a test using ==, NOT =. the single = performs an assignment, which is not legal inline like that.

There must be many other problems, since the code you have not written is invalid MATLAB syntax in many places. This code will not run forever. In fact, it will fail to run immediately in MATLAB.

[Jonathan Ashley]

well sorry to say John this did work in matlab and since theres no other B# in my code throughtout the whole. I think your response doesn't help me very much.