.dat file to a readable file for an array in MATLAB

I want to read a .dat file that has columns and rows of information into a MATLAB function so I can make array indexing with the function variables, and call that function into another script. How would I be able to read the file into a function, when it is formated as .dat? Can I make my own file with the information it has inside into a readable format for MATLAB?

I want to use it for array indexing so I can define some variables withing the function

Example:

function [ A, B, C, D, E, F, G] = script#0 ( file_I_want_to_read)

^ ^

Variables This is where the file_I_want_to_read for the purpose of array indexing the contents in the file, for defining my variables

fileid = fopen( file_I_want_to_read, 'r');
format = ['%s', repmat('%{   .............ect.
K = textscan( fileid, format, 'Delimiter', '\t' );
fclose( fileid );

[Walter Roberson]

You might be able to use readtable() with FileType 'text' option

[Giovanni Ponce]

how would I use the format I already have for reading the file? I converted the .dat file to a .txt file and it still gives me an error.

>>script#0

Error using textscan

Invalid file identifier. Use fopen to generate a valid file identifier.

Error in uigfread (line 10)

U = textscan( uigffid, format, 'Delimiter', '\t' );

[Walter Roberson]

Note: # is not a valid character as part of .m file name.

[Walter Roberson]

The file that you fopen()'d was not available under the name you asked for. Perhaps it is not in the current directory but you did not include the directory information?

[filename, dirname] = uigetfile('*.dat');
if ~ischar(filename)
    return;   %user cancel
end
fullname = fullfile(dirname, filename);

[uigffid, msg] = fopen(fullname, 'r');
if uigffid < 0
    error("Could not open file '%s' because '%s'", fullname, msg);0
end

U = textscan(uigffid, format, 'Delimiter', '\t');

fclose(uigffid);

Answer 1

[Siraj]

Hi! It is my understanding that you want to read a .dat file with columns and rows of information into a MATLAB function for array indexing and variable definition.

One of the methods to read a ".dat" file is by utilizing the "textscan" function in MATLAB. This function is designed to read formatted data from a text file and store it in a cell array. You can use the "textscan" function to read ".dat" files, ensuring that you specify the appropriate formatting and only read the relevant data. The "textscan" function offers several name-value arguments that allow you to control which lines to read and which lines to skip. For more detailed information and examples, you can refer to the following link:

https://www.mathworks.com/help/matlab/ref/textscan.html

Consider the following example for better understanding

I have a ".dat" file named "example.dat" with the following contents:

#   (EXCLUDING parts overlapped by quadrics)
#
# Dose units are eV/g per primary history
# Number of voxels in x
#  3 1 3
# Voxels size dx
#   1.00000E+01  1.00000E+00  1.00000E+01
# The granularity used to compute the voxels mass was:
# 10
#
# For plotting purposes
#   the low end and the middle point of each voxel
#
# xLow(cm) : xMiddle(cm) : yLow(cm) : yMiddle(cm) : zLow(cm) : zMiddle(cm) : dose (eV/g) : +-2sigma : voxel mass (g) : Pure(+)/Overlapped(-)
# zVoxIndex=1 
# yVoxIndex=1 
1.2 3 4.0
1.2 3 4.0
1.2 3 4.0


# zVoxIndex=2 
# yVoxIndex=1 
1.5 6 7
1.5 6 7
1.5 6 7

# zVoxIndex=3 
# yVoxIndex=1 
1.9 8 90
1.9 8 90
1.9 8 90

The "textscan" function is used to read the contents of the file "example.dat". The data is extracted and stored in different variables.

% Open the file for reading 
file = 'example.dat'; 
fid = fopen(file, 'r'); 
 
% Read the data using textscan and skip lines starting with '#' 
datacell = textscan(fid, '%f %f %f', 'Delimiter', '\t', 'CommentStyle', '#'); 
 
% Close the file 
fclose(fid); 
 
%extracting the data read into variables. 
A = datacell{1}; 
B = datacell{2}; 
C = datacell{3}; 
 
t = table(A,B,C)

The provided example can be customized based on the specific file you have. However, I hope that the example provided has helped clarify the process of using the "textscan" function to read a ".dat" file and extracting the data into different variables.