while loop with if-statements to set criteria for data.

Hello! I have a funktion that gets a data file as input. The function should then run through each line of the data file to check whether each line passes some criterias. If the line does not pass the criterias the fucntion should just skip that line and go to the next line without saving anything to the output variables. My problem is that even though a line is corrupted it is still saved in the output variable eventhough the function prints the "skipping line"-message. Can anybody please help me with this problem? Here is my function

function [W,D,t,C,filename] = load_data(filename)
fid = fopen(filename,'r'); 
i=0; 
while feof(fid) == 0 
  i=i+1; 
strLine = fgetl(fid); 
numLine = str2num(strLine);
if numel(numLine)>1 && min(numLine(1))>=20 && max(numLine(1))<=200 && min(numLine(2))>=50 && max(numLine(2))<=500 
  if issorted(numLine(3:2:end)) && issorted(flip(numLine(4:2:end))) && length((numLine(4:2:end)))==length((numLine(3:2:end))) 
      if min(numLine(3:2:end))>=0 && max(numLine(3:2:end))<=360 && min(numLine(4:2:end))>=0 && max(numLine(4:2:end))<=50 && length(numLine(4:2:end))>=2 
 W(:,i) = numLine(1); 
 D(:,i) = numLine(2); 
 t{:,i} = numLine(3:2:end); 
 C{:,i} = numLine(4:2:end);
      else
 fprintf('Line nr %1.f is skipped\n',i) 
      end
  else
      fprintf('Line nr %1.f is skipped\n',i) 
  end
else 
      fprintf('Line nr %1.f is skipped\n',i) 
   end
end
end

Answer 1

[dpb]

i=0; 
while ~feof(fid)
  strLine = fgetl(fid); 
  numLine = str2num(strLine);
  if numel(numLine)>1 && min(numLine(1))>=20 && max(numLine(1))<=200 ...
                      && min(numLine(2))>=50 && max(numLine(2))<=500 
    if issorted(numLine(3:2:end)) && issorted(flip(numLine(4:2:end))) ...
                 && length((numLine(4:2:end)))==length((numLine(3:2:end))) 
      if min(numLine(3:2:end))>=0 && max(numLine(3:2:end))<=360 && ...
         min(numLine(4:2:end))>=0 && max(numLine(4:2:end))<=50 && ...
        length(numLine(4:2:end))>=2 \
        i=i+1; 
        W(:,i) = numLine(1); 
        D(:,i) = numLine(2); 
        t{:,i} = numLine(3:2:end); 
        C{:,i} = numLine(4:2:end);
      else
        fprintf('Line nr %1.f is skipped\n',i) 
      end
    else
      fprintf('Line nr %1.f is skipped\n',i) 
    end
  else 
    fprintf('Line nr %1.f is skipped\n',i) 
  end
end

Answer 2

[Lars]

Hey guys I found the problem. The i variable should be inside the if statement and i needed to make a new variable q for it to work. Thanks anyways. Like this

function [W,D,t,C,filename] = load_data(filename)
fid = fopen(filename,'r'); 
i=0; 
q=0;
while feof(fid) == 0 % 
    q=q+1;
strLine = fgetl(fid); % 
numLine = str2num(strLine);% 
if numel(numLine)>1 && min(numLine(1))>=20 && max(numLine(1))<=200 && min(numLine(2))>=50 && max(numLine(2))<=500 
    if issorted(numLine(3:2:end)) && issorted(flip(numLine(4:2:end))) && length((numLine(4:2:end)))==length((numLine(3:2:end))) 
        if min(numLine(3:2:end))>=0 && max(numLine(3:2:end))<=360 && min(numLine(4:2:end))>=0 && max(numLine(4:2:end))<=50 && length(numLine(4:2:end))>=2 
   i=i+1; 
            W(:,i) = numLine(1); 
   D(:,i) = numLine(2); % (:,i) 
   t{:,i} = numLine(3:2:end); 
   C{:,i} = numLine(4:2:end);
        else
   fprintf('Line nr %1.f is skipped\n',q) 
        end
    else
        fprintf('Line nr %1.f is skipped\n',q) 
    end
else 
        fprintf('Line nr %1.f is skipped\n',q) 
     end
end

[dpb]

...The i variable should be inside the if statement and i needed to make a new variable q for it to work.

The Answer I had previously posted.

[Lars]

Thanks a lot. Now i see you had already solved the problem. :-)

[dpb]

Altho I'd presumed you didn't really care that much about the skipped line numbers...

Answer 3

[Image Analyst]

If you want to make it easy for people to help him, then he should attach the file you're using. I just don't see how it's possible for it to assign column "i" of W, D, t, and c if it prints the "skipped" line. Those columns of the cell arrays t and c should all be null. Other columns may get assigned, but the ones you skipped will be null for t and c.

What is the size of the regular numerical arrays W and D? How can you say W(:,i) for the first time when you have not allocated any rows or columns for W yet?

[Lars]

I have now tried to upload the file. Thanks

[dpb]

The issue is that the original increments i every time whether the if conditions are met or not--I moved it to be inside the selection section.