"Error using fscanf"

i got error which saying "Invalid file identifier. Use fopen to generate a valid file identifier"

This is the code:

function [z] = Stereo( directory, imagename, numImages)

% ***********************************************************************

% Read the lights and directions:

% ***********************************************************************

lightfile = strcat( directory, '/', 'lights2.txt')

fid = fopen(lightfile, 'r');

numLights = 1;

numLights = fscanf(fid, '%d \n', [1]);

LightMatrix = [];

for i = 1:numLights

lightDir = fscanf(fid, '%f %f %f \n', [3]);

lightDir = lightDir/norm(lightDir);

lightMatrix(i,:) = lightDir;

end

this is the lights2.txt file

Can someone help me i m so curious about this. Bigh thanks for your help

[Stephen23]

Replace this command

strcat( directory, '/', 'lights2.txt')

with

fullfile( directory, 'lights2.txt')

And forget about using FOPEN & FSCANF: just use READMATRIX to import that file data:

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

If you use FOPEN then always always always remember to FCLOSE afterwards!

Answer 1

[Askic V]

You're getting this error because the path to your file is not correct.

this is where the problem is:

 lightfile = strcat( directory, '/', 'lights2.txt')

Print/Display this variable to see the path to the file.

BTW, if your file is structured like in the posted image, I suggest to use readmatrix function instead of fopen and fscanf.

[pizzaa]

When i run the code "lightfile" can be read.

[pizzaa]

can u help me with the code in using readmatrix

[pizzaa]

Nice ty so much