Import Multiple Text Files into multiple arrays

I have 62 flies - each file has 4 columns containing variable number of rows (between 226-300 rows). The number of rows corresponds to the number of raindrops. The first column is the X coordinate of the start of the raindrop, the second column is theh Y coordinate of the start of the raindrop. The last two columns are the X and Y coordinates of the end of the raindrop. The data is decimals

The files all have the same start to the name 'XYpoints_timeFromDeparture_Z.txt' where Z is 0,30,60 etc all the way to 1830

I need to find a way, using a for loop, to import all the data - then each file needs to put the data from cells into arrays.

This is how I did it for one file:

fileName = 'XYpoints_timeFromDeparture_0.txt'; 
fileID = fopen(fileName);
XXYY = textscan(fileID,'%f %f %f %f'); % puts the data into cells
fclose(fileID);
A = cell2mat(XXYY) % cell to array

we have XXYY which is a 1x4 array. Each cell is a vector (Xa, Ya, Xb, Yb)

What I need to do is make a an array as a 62x1. Each cell needs to have the XXYY which then has the vector per cell.

I tried using this code.

for i = 0:30:1830
    fileName ='XYpoints_timeFromDeparture_%d.txt', i; 
    fileID = fopen(fileName);
    XXYY = textscan(fileID,'%f %f %f %f'); % puts the data into cells
    fclose(fileID);
    A = cell2mat(XXYY) % cell to array
    
end

Doing this, gets me the error using textscan

[per isakson]

replace

fileName ='XYpoints_timeFromDeparture_%d.txt', i; 

by

fileName =sprintf( 'XYpoints_timeFromDeparture_%d.txt', i ); 

And notice that you overwritr A in each iteration

[Shrisha Panda]

how do i prevent that?

[Stephen23]

"how do i prevent that?"

See the examples in the MATLAB documentation:

https://www.mathworks.com/help/matlab/import_export/process-a-sequence-of-files.html

Answer 1

[Stephen23]

D = 'path to the directory where the files are saved';
V = 0:30:1830;
N = numel(V);
C = cell(1,N);
for k = 1:N
    F = sprintf('XYpoints_timeFromDeparture_%d.txt',V(k));
    [fid,msg] = fopen(fullfile(D,F),'rt');
    assert(fid>=3,msg)
    C(k) = textscan(fid,'%f%f%f%f', 'CollectOutput',true);
    fclose(fid);
end

All of the imported data will be in the cell array C:

https://www.mathworks.com/help/matlab/matlab_prog/access-data-in-a-cell-array.html

[Shrisha Panda]

When I use this code, cell array C is a 1x62 (which is great!) but each cell is empty. I need each cell to have an array of a 4x1 and each row to have a vector (which is the column of data from the text file)

[Shrisha Panda]

Now there's this error

Error using fopen

Invalid permission.

Error in q2 (line 8)

[fid,msg] = fopen(fullfile(D,F),' rt');

[Stephen23]

For some reason you added a space character:

fopen(fullfile(D,F),'rt')   % My answer shows this
fopen(fullfile(D,F),' rt')  % You tried this
%                    ^ You added this

[Shrisha Panda]

Ah yes - it works perfectly now thank you!