sprintf problems

Hello i have a file path which is this '\\psf\Home\Documents\MATLAB\silhouettes\1\00_1' This points to a set of images that i need to add to matlab which works fine. what i need to happen is that when this code is run it changes the one to a two so it would look like this '\\psf\Home\Documents\MATLAB\silhouettes\2\00_1' and then change to three and four etc, i have been told i can use sprintf to do this but cannot see a way to make it work, i don't suppose any out there has any sprintf knowledge who could help me out?

thanks Rob

Answer 1

[Matt Fig]

I assume you are using the string in a loop. If not, adjust accordingly.

for ii = 1:5
S = sprintf('\\\\psf\\Home\\Documents\\MATLAB\\silhouettes\\%i\\00_1\n',ii)
end

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In reply to your email:

The SPRINTF function creates a formatted string. the %i is the format specifier which tells SPRINTF to turn the argument (ii) into an integer. Also notice that you had to have two backslashes everywhere you wanted a single backslash printed. The backslash is the escape character, so SPRINTF doesn't print what is after it (like the \n at the end). I recommend reading the doc on this function, because it comes up all the time!

[rob wise]

ah i see, thanks for that. is there a simple way to make it run the function after it increases the number each time, because at the moment its only adding the last photo set. i hope i'm making sense and not sounding to stupid, i've never really played with this before.

[Matt Fig]

What function? Are using the string to change paths, then you want the function to run? If so, you should simply call the function after the path is changed, assuming your function is located somewhere on the MATLAB search path (i.e., it can be reached from any folder).

[rob wise]

basically the path points to a folder with different images, when the program is run it adds to images to a database, i need it to change the path name, then run the program so it imports the images, then change the path name and adds the images and carries that on.

[Matt Fig]

You will want to use the CD function on your paths generated above, and also to get back. Just make sure to save the main path first, something like:

P = pwd;

for ii = 1:?

% Create S as above.

cd(S)

% call function, create variables, whatever

cd(P)

% Store variables in database, whatever

end

Answer 2

[Walter Roberson]

Adjusting Matt's answer slightly to make it more intuitive to program:

for ii = 1:5
  S = sprintf('%s%d%s, '\\psf\Home\Documents\MATLAB\silhouettes\', ii, '\00_1')
end

[rob wise]

it didnt like it, threw this up

??? S = sprintf('%s%d%s,'\\psf\Home\Documents\MATLAB\silhouettes\', ii, '\00_1')

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Error: Unexpected MATLAB operator.

[Matt Fig]

Walter meant:

S = sprintf('%s%d%s', '\\psf\Home\Documents\MATLAB\silhouettes\', ii, '\00_1')

This is the multi-arg version of the solution!

[Matt Fig]

Speaking of which... It is funny Walter, I learned from you (NG posts) to inline my strings to SPRINTF, rather than passing multiple arguments and one formatter string at the beginning (how I always used to do it)!

[Walter Roberson]

Yeah, but I don't program on Windows with all those \ characters in pathnames. When I start getting strings with numerous \ then I switch styles.

Well, actually if I were programming it myself, I would code inline but use / instead of \\ since Windows will accept / in place of \ .