MATLAB: Sscanf is truncating the floating point number

MATLABsscanf

I am trying to use sscanf to extract data from a string, but it is truncating my floating point number. The code I am using is:

sscanf(tempstr, '%f V,%d counts,%d ms')

The data is like this: 0.2981427192 V,34 counts,500 ms

I get: ans =

    0.2981
   34.0000
  500.0000

I want all the floating point digits. I have tried to specify a length (%12f), and numerous other things, none of which have worked. Any help would be appreciated.

Thanks Rebecca

Best Answer

Type:

format long g

in your script or Command Window before your sscanf call. All the digits should be visible.

Related Solutions

MATLAB: Creating an array from a txt file

The reason your textscan does not work is simply because the first column (the probe name) is not made of numbers so the '%f' format fails on that. This would work (and is much better than the whole file parsing suggested by Andreas):

fid= fopen('ifng.txt','r');
A = textscan(fid, ['%s', repmat('%f', 1 , 25)], 'HeaderLines', 1);
Anumbers = [A{2:end}];

Note that in the header, your file uses a combination of tabs and spaces as the delimiter. If you actually fixed that, then reading the file would be as simple as:

t = readtable('ifng.txt', 'Delimiter', 'tab');  %or 'space' if you replace the tabs by spaces

As a bonus you get the header read properly as variable names, so you don't even need to skip it.

MATLAB: How to read a specified, comma seperated text (txt) file line-byline

Now, you say that you'd like the 3 numerical values which can be obtained by:

fileID=fopen('data.txt','r');  % I've removed the 't'  
  while feof(fileID)~=1
  line=fgetl(fileID);            % as per OP
  a = cell2mat((textscan(line,'%f V,%f counts,%f ms'))); % a is a 3x1 matrix
  display(a)
  % do something with 'a'
  end
  fclose(fileID);

However, if you wanted to read the file in one go... you could use:

fileID=fopen('data.txt','r');  % I've removed the 't'
  a = cell2mat(textscan(fileID,'%f V,%f counts,%f ms'));
  fclose(fileID);
  display(a)

There are further improvements that can be made to this code (checking that the file opens correctly, using more appropriate data types etc etc) but this should achieve what you intend.

Best Answer

Related Solutions

MATLAB: Creating an array from a txt file

MATLAB: How to read a specified, comma seperated text (txt) file line-byline

Related Question