iteration on file name

Hi guys, would anyone be kind enough to explain me this?

So i have to load many datas.

datas are named as follow:

f_1_000_010; f_2_000_020; f_3_000_030; f_4_000_040; f_5_001_000; f_6_001_010; f_7_001_020; f_8_000_030; f_9_000_040; f_10_002_000 ..... and so on.

basically the second term is +1 every time the third term reach 5.

i how do I tell matlab to do that?

[Stephen23]

"i how do I tell matlab to do that? "

https://www.mathworks.com/help/matlab/import_export/process-a-sequence-of-files.html

Answer 1

[the cyclist]

Here is one way:

for nf = 1:10
    
    str1 = sprintf('%d',nf);
    str2 = sprintf('%d',mod(nf-1,5)+1);
    
    filename = ['f_',str1,'_000_0',str2,'0'];
    
end

The key features of the algorithm are

• use of sprintf to convert the numerics to strings, for a given pattern
• use of the mod function to implement the "cycle" from 1-5
• concatenation of strings into one

One doesn't really need to pull the creation of the string into three separate calculations, so this is slicker:

for nf = 1:10
    filename = ['f_',sprintf('%d',nf),'_000_0',sprintf('%d',mod(nf-1,5)+1),'0']; 
end

but the first way might be easier to understand. The whole thing could also be boiled down to a single use of sprintf:

for nf = 1:10
    filename = sprintf('f_%d_000_0%d0',nf,mod(nf-1,5)+1);
end

[the cyclist]

"but what if i have something like this instead"

My immediate and emotional reaction to that phrase is something like ...

• Did I solve your first problem, and this is a new problem?
• If yes, then maybe accept this solution, and start a new question.
• If not, why did you waste our time and not just post this in the first place?

OK, so now I've processed my emotions.

My next reaction is a mix of emotional and rational:

If you really take the time to understand my solution, I'd really think you ought to be able to solve this problem. Have you?

Finally, and probably most helpfully, I notice that you probably want

if j==0
    ...
end

instead of

if j=0
    
end

[Murstoe]

sorry, i just wanted to understand the reason of it rather than give you my problem to solve it. i wasnt eble to so i asked you again. annoy you wasn't my purpose and i apologize.

it looks like it still deosn't work properly. "f_001_000_080_Int_32F.tif" does not exis". it should be f_002_000_080_Int_32F.tif !.

[the cyclist]

No problem.

So, it looks like you have solved your problem of creating the file name string, but have underlying logic issues in how you have implemented the loop and if statements.

Unfortunately, I can't even get your code to run, because of syntax errors.

First, can you confirm that you changed

if j=0

to

if j==0

?

Next, if I do make that change, your code crashes for me because k is not yet defined the first time it tries to create the file name. It is confusing to me why you have both k0 and k defined, and I can't guess at what you are trying to do.