Change value of corresponding column depending on conditions

Helllo! I have a 23000x14 table of data. Im trying to do something where I go through all of the values in column 10 and if it column 10 gives the value of 15 then the same row that has that values of 15 but in column 9 gets changed to 'NA'. So for exmaple:

Original

5 4

45 15

32 6

After

5 4

NA 15

32 6

I've tried a few things but nothing has worked for me so far. Any help is greatly appreciated, thank you!

Answer 1

[KSSV]

You cannot put NA, but you can replace that with NaN. Try this.

A = [5          4      
45       15
32        6] ;

idx = A(:,2)==15 ;   % get logical indices of second column which has 15 
A(idx,1) = NaN ;     % replace the first column with NaN which has 15 in the second column 

[Claire Hollow]

Just a reminder I am doing this for a table. So I tried:

idx=station001_eus{:,10}==(',,7');
station001_eus{idx,9}=NaN;

and got the error

Invalid RHS for assignment to a categorical array.

for the second line. Any ideas on how to get around this?

[KSSV]

If it is table, you should be able to add NA....make it a string and try to add..

station001_eus{idx,9}= 'NA';

[Claire Hollow]

Ok so now I did try that

idx=station001_eus{:,10}==(',,7');
station001_eus{idx,9}='NA';

and im getting the error

The value on the right-hand side of the assignment
has the wrong width. The assignment requires a
value whose width is 1.

for the second line again. Im not sure how to work past this.

Sorry for the all the questions, you've been super helpful!