undefined function type double

Good evening friends,

i have a very simple problem with this code(but my brain is out of service and i need to solve it by tomorrow)

arr=1;
deltaTe=0.5;
deltaTemax=80;
imax=100;

for giorno=1:365
nname=['Tuttigiorni/Variazionegiorno_',num2str(giorno),'.txt'];
        nfid=fopen(nname,'r');
        while ~feof(nfid)
            hhead=fscanf(nfid,'%f',2);   
            if ~isempty(hhead)
               gggradi(arr)=hhead(2);
               ggradi(arr)=fix(gggradi(arr));
               i=fix(ggradi(arr)/deltaTe)+1;
               vettore(i)=vettore(i)+1;              
            end
            arr=arr+1;
        end
end
vettore

Error: Undefined function 'vettore' for input arguments of type 'double'. I want to save i value in the vettore array Thanks so much

Answer 1

[Sajid Khan]

it you don't have anything in vettore, then how can you perform the step vettore(i)=vettore(i)+1;

[Nicola]

Thanks man! Yesteray my brain was out of service ;)

Answer 2

[Walter Roberson]

The files are all empty, or the first line of each file begins with something that is not understandable as a number.

[Nicola]

No,i checked and it takes right the first value(ggradi=21), but it doesn't put i in array vettore(43). 43=fix(21/0,5)+1

I don't understand why i should initialize it with vettore=zeros(1,200) for example, why shouldn't it auto-create?

[Walter Roberson]

Ah you did not include the traceback of messages so I thought the message was referring to the vettore at the end of the program, which indeed would not exist in the circumstances I mention.

You are starting off with vettoree completely undefined. Then you are trying to calculate vettore(43)+1 and assign that value somewhere. But the vector does not exist, so it is going to complain. It does not create the location to be assigned to until after it has evaluated the right-hand side. So preallocate.

Note: you are not putting "i" into the location, you are adding 1 (the digit) to the location, so you are counting the occurrences.

[Nicola]

Thanks!

Answer 3

[Image Analyst]

I think it's never getting into the while loop to set vettore because it can't open the file. Here, put this code in right before you call fopen():

% Read in the file.
folder = ''Tuttigiorni';
baseFileName = sprintf('Variazionegiorno_%d.txt', giorno;
% Get the full filename, with path prepended.
fullFileName = fullfile(folder, baseFileName);
% Check if file exists.
if ~exist(fullFileName, 'file')
  % File doesn't exist -- didn't find it there.  Check the search path for it.
  fullFileName = baseFileName; % No path this time.
  if ~exist(fullFileName, 'file')
    % Still didn't find it.  Alert user.
    errorMessage = sprintf('Error: %s does not exist in the search path folders.', fullFileName);
    uiwait(warndlg(errorMessage));
    return;
  end
end

Then call fopen:

nfid = fopen(fullFileName ,'r');

[Walter Roberson]

If it had been unable to open the file then the feof() would have error'd out in an obvious manner before it tried to use the variable.

[Nicola]

Thanks! It opened the file, the problem was that i didn't initialize the array vettore!