how can I open any file with a .TXT file, read and print the data correctly?

function graphData = graphData()
%This fucntion will make graphs comparing relevant parameters from my
%output.TXT files

%open the output.txt file

fileID = fopen('*.TXT', 'r');

%initialize variables
startRow = 6;

%format the data 
formatSpec = '%3s%21s%4s%6s%6s%6s%10s%4s%6s%7s%4s%6s%12s%6s%s%[^\n\r]';

  %turn the data from the file into a table 
% textscan(fileID, formatSpec);

% dataArray = textscan(fileID, formatSpec, 'Delimiter', '', 'WhiteSpace', '', 'TextType', 'string', 'ReturnOnError', false);
  
textscan(fileID, '%[^\n\r]', startRow-1, 'WhiteSpace', '', 'ReturnOnError', false, 'EndOfLine', '\r\n');
dataArray = textscan(fileID, formatSpec, 'Delimiter', '', 'WhiteSpace', '', 'TextType', 'string', 'ReturnOnError', false);

%remove white space around columns 
dataArray{1} = strtrim(dataArray{1});
dataArray{2} = strtrim(dataArray{2});
dataArray{3} = strtrim(dataArray{3});
dataArray{4} = strtrim(dataArray{4});
dataArray{5} = strtrim(dataArray{5});
dataArray{6} = strtrim(dataArray{6});
dataArray{7} = strtrim(dataArray{7});
dataArray{8} = strtrim(dataArray{8});
dataArray{9} = strtrim(dataArray{9});
dataArray{10} = strtrim(dataArray{10});
dataArray{11} = strtrim(dataArray{11});
dataArray{12} = strtrim(dataArray{12});
dataArray{13} = strtrim(dataArray{13});
dataArray{14} = strtrim(dataArray{14});
dataArray{15} = strtrim(dataArray{15});
dataArray{16} = strtrim(dataArray{15});
%close the text file
fclose(fileID);

%create a variable to store all output values
output = [dataArray{1:end}];

%convert string output to character output and then to a numeric output
dataChar =  convertStringsToChars(output);
dataNum = str2double(dataChar);

%% Clear temporary variables
clearvars filename startRow formatSpec fileID dataArray ans;

%%plot the three graphs at once


  clf 
%lwd=2;
fsz=30;
figure(1);

%Sum the duration from output files
sumDur = dataNum(:,7);

graphData = plot(dataNum(:,2), dataNum(:,9));
grid minor
xlabel('Time (seconds)', 'FontSize', fsz)
ylabel('Frequency (KHz)', 'FontSize', fsz)

figure(2);

 

plot(dataNum(:,2), dataNum(:,8))
grid minor
xlabel('Time (seconds)', 'FontSize', fsz)
ylabel('Amplitude (db)', 'FontSize', fsz)

figure(3);

 

plot(dataNum(:,2), 17383/sumDur)
grid minor
xlabel('Time (seconds)', 'FontSize', fsz)
ylabel('Events', 'FontSize', fsz)

end

Answer 1

[dpb]

fileID = fopen('*.TXT', 'r');

is invalid syntax-- fopen() can't use wild cards; tha'ts a dir functionality--

d=dir('*.TXT');
for i=1:numel(d)
  fid=fopen(d(i).name, 'r');
  ...

But, looks like a very difficult and inefficient way to read a text file -- instead define the format of the file and read the numeric data directly.

Showing a small sample data file would help immeasurably.

There probably are also higher-level functions like readtable or even importdata to ease the task greatly as compared to lower-level routines. If it is as appears may be a fixed-width text file, using the detectImportOptions function for a fixedWidth import object is probably a help in abstraction level.