unable to open a text file from different loacations

i am using the following code to get the .txt file from any location

a1 = uigetfile('../Data/*.txt');
fid = fopen(a1,'r+');

i am able to select .txt files which are present only in matlab working folder. if i place the same file on desktop and try to select it i get an error as shown below

 Error using textscan
Invalid file identifier.  Use fopen to generate a valid file identifier.
Error in text_fin1 (line 7)

c = textscan(fid,'%d64%f64%s%s%d64%d64%d64%d64%d64','delimiter',
';','HeaderLines',256);

please let me know why i have this error, how to remove it

Answer 1

[Jan]

uigetfile replies the path and the file name. You have to use both to address your file:

[filename, pathname] = uigetfile('*.txt');
fid = fopen(fullfile(pathname, filename), 'r+');

Otherwise Matlab searches the file in the current folder. For fopen(name, 'r') Matlab would even search in the complete Matlab path, which might lead to very unexpected effects. But fortunately the write-permissions triggered by 'r+' let fopen be less smart.

[shanmukh]

i used the following code

a1 = uigetfile('*.txt');

fid = fopen(fullfile(a1), 'r+');

no use it gives me the same error