Can you please explain these line of code?

fid = fopen( geomFile );

xPos = zeros(1,geoSize);

for kk = 1:geoSize; 
    xPos(kk) = fread( fid, 1, '*uint32' );

end

fclose(fid);

max_xPos = max(xPos);

xdim = max_xPos - min_xPos +1;

Any kind of help is appreciated!!

Answer 1

[Geoff Hayes]

Mohammad - why not step through the code to see what is happening? A file is opened, three matrices are sized, then an x and y an z coordinate is read for each element in the three matrices. The file is closed, and the min and max (x,y,z) coordinate is found. For more information on each function type the following in the Command Window

 doc fopen
 doc fread
 doc fclose
 doc min
 doc max

As for why the code is doing this, hopefully you have an idea on that! :)

[Mohammad Wajih]

thank you for your answer . but what does these line mean

xdim = max_xPos - min_xPos +1;
ydim = max_yPos - min_yPos +1;
zdim = max_zPos - min_zPos +1;

[Geoff Hayes]

The author of the code is calculating the difference between the minimum and maximum (say) x coordinate/position. So if

 max_xPos = 9;
 min_xPos = 3;
 xdim     = max_xPos - min_xPos + 1 = 9 - 3 + 1 = 7

Why he/she chose to call this difference xdim or how this and the other variables are to be used is unknown given the few lines of code that you have presented (none of which is commented). If you want a better understanding of the code, then contact the author.

[Mohammad Wajih]

Thank you Mr. Hayes for your answer. Actually, I don't know who the author of this code is. This code used to work for me but now I don't know why its not working. So, I am trying to understand each and every line. Thanks for your response. I really appreciate it.

[Image Analyst]

I agree with Geoff: calling them dim is a horrible name for the variables since it's really the range of the data, not the dimensions. For example if the data range from 1000 to 1005, that does not mean that the dimension of an array to hold all that data should be 6 - there could be hundreds of pixels in that range. But you really have to define what "its not working" means to you for us to fix it.