How do I print out a sequence of numbers on a text file using fprintf??

%Print values into text file

centx = props.Centroid(1)

centy = props.Centroid(2)

fprintf('imagenumber',centx, centy);

I've already got the values of the centx and centy, and they are generated fine. The only issue is I would like a numbered list for each value of centx and cent y.

e.g.

image number cent x cent y

1 0.1 0.2

2 0.2 0.4

3 0.3 0.6

4 0.4 0.8

etc.

I hope someone can help me with this!

Answer 1

[KSSV]

fid = fopen('test.txt','w')  ;
fprintf(fid,'%s %s %s\n','Imaage Number','centx','centy') ;
n = 10 ; 
for i = 1:n
    fprintf(fid,'%d      %f %f\n',i,rand,rand) ; 
end
fclose(fid) ; 

[Syamsundar Menon Murali Mohan]

Is there supposed to be a space in between this command?:

fprintf(fid,'%d %f %f\n',i,rand,rand) ;

[KSSV]

Up to you.....If not numbers will encroach uder Image Number. See the generated files with and witout spaces.

[Syamsundar Menon Murali Mohan]

Its appearing like this instead:

[KSSV]

How? Show us the code which you have tried. They should appear as shown below:

fprintf('%s %s %s\n','Imaage Number','centx','centy') ;

Imaage Number centx centy

n = 10 ; 
for i = 1:n
    fprintf('%d      %f %f\n',i,rand,rand) ; 
end

1      0.099398 0.361086
2      0.989420 0.896952
3      0.488606 0.010184
4      0.609460 0.355617
5      0.095150 0.486920
6      0.797712 0.745627
7      0.209521 0.994732
8      0.542188 0.165796
9      0.291636 0.173902
10      0.827902 0.040092

[Syamsundar Menon Murali Mohan]

This is what is being produced at the moment now. I'm getting that numbered list. However, the values are not what I want. What I require are the values of 'centx = 185.8174, 185.8387,185.7654,.....' and 'centy = 751.1315, 744.1576, 737.6045,....'

The code that I'm using is as below:

fprintf('%s %s %s\n','Image Number','centx','centy');
n = 94; 
for i = 1:n
    fprintf('%d      %f %f\n',i,rand,rand) ; 
end

*I used n = 94, because I have 94 images to process

[Syamsundar Menon Murali Mohan]

I need it like this exactly:

image number cent x cent y

1 185.8174 751.1315

2 185.8387 744.1576

3 185.7654 737.6045

This sort of form

[Walter Roberson]

fid = fopen('test.txt','w')  ;
fprintf(fid,'%s %s %s\n', 'Image Number', 'centx', 'centy') ;

dinfo = dir('*.png');
filenames = {dinfo.name};

n = length(filenames);
for i = 1 : n
    TheImage = imread(filenames{i});
    if ndims(TheImage) > 2; TheImage = rgb2gray(TheImage); end
    BW = imbinarize(TheImage);
    BW = bwareafilt(BW, 1);
    props = regionprops(BW, 'Centroid');
    %Print values into text file 
    centx = props.Centroid(1);
    centy = props.Centroid(2);
    fprintf('%d      %f %f\n', i, centx, centy); 
end

fclose(fid);

[Syamsundar Menon Murali Mohan]

I'm getting this instead, which is not what I want.

The numbered list is repeating itself with the same values. Each number in the numbered list should have the next value, not the exact same value.

[Walter Roberson]

Under what circumstances is the count restarting? Is it restarting once for each file? Are you doing multiple runs with the same sets of files and appending to the output? Are you doing runs over different directories and appending to the output?

Is it possible that you are detecting multiple regions for each image and wanting to save the centroid for each region? If so then it is not clear to me that the numbering should be continuing through all of the files: how would you determine where each file ended in the list?

For that matter, even if there is only one output per file, how do you make it clear which output line corresponds to which input file?

[Syamsundar Menon Murali Mohan]

1. I am essentially detecting the centroid for a whole range of images
2. Each image has its own centroid value, and I'm trying to include that within a numbered list.
3. The reason that I'm doing a numbered list is so that I can eventually transfer it into an Excel file and plot the different centroids based on the values that I extracted over the whole range of images

Would that not be possible? I'm a beginner in MATLAB so I was hoping I could get some clarification if this may be possible.