How to insert a number in a txt template

Dear All,

I have a (50*1) matrix whose elements are random integers. Also, I have a text file template. I need to write a code in which i can call the first element of my matrix and insert than number in the specific location of my text file. Then, the output should be saved as file1.txt. For all of the 50 elements of the matrix I need to create 50 output files i.e. file1.txt to file50.txt.

The line number which my number should be inserted in is 74, and has the following format:

 velocity         all create 5000  mom yes dist gaussian

well, now if my random number is a 7-digits integer like 1234567, this line will change into :

 velocity         all create 5000 1234567 mom yes dist gaussian

and if the random number in the matrix is a 6-digits integer like 123456, the mentioned line will have to change into:

 velocity         all create 5000 123456 mom yes dist gaussian

As you can easily see, there are two spaces between 5000 and mom in this line. What I need is to insert my number, whatever it is, in between 5000 and mom starting from column # 34. Obviously, the line should be extended by 7 columns to the right if the integer has 7 digits, and similarly for 6-digits integers and etc.

I do appreciate if anyone can help me with this issue. It can save me mucg time.

Thanks.

Best,

HRJ

Answer 1

[Star Strider]

This should do what you want:

N = randi(1E8, 50, 1);

for k1 = 1:length(N)
    fid = fopen(sprintf('file%d.txt', k1),'wt');
    fprintf(fid, 'velocity         all create 5000 %d mom yes dist gaussian', N(k1))
    fclose(fid);
end

NOTE: I did not test this because I didn’t want to create and then have to delete all those files.

[Walter Roberson]

Between the fopen() and the fprintf() shown, you would write out the first 73 lines of the template. After the fprintf() shown you would write out the remaining lines of the template.

To get the spacing correct, the format Star Strider gives should be modified slightly. It should be:

      fprintf(fid, 'velocity         all create 5000 %7d mom yes dist gaussian', N(k1));

This will output at least 7 digits with leading spaces if needed.

[Homayoon]

can you help me on this please?

Dear All,

Well I have a text that I have to fprintf it into a text file using my matlab code. But I cannot figure what the output is not what I expect. Is there anything wrong with my code?

Here is the text I need to be written in my output file:

 dump_modify     1 format "%5d   %5d     %25.10g %25.10g %25.10g"
 dump_modify     1 sort id

Here is my code:

 fprintf(fid,'dump_modify     1 format "%5d   %5d     %25.10g %25.10g %25.10g" \n\')
fprintf(fid,'dump_modify     1 sort id\n\n')

but the output is something strange!

 dump_modify     1 format "dump_modify     1 sort id

Thanks so much for helping me.

[Walter Roberson]

fprintf(fid,'%s\n', 'dump_modify     1 format "%5d   %5d     %25.10g %25.10g %25.10g"');
fprintf(fid,'%s\n\n', 'dump_modify     1 sort id');