fopen function how to use a variable name to select a file present in a folder?

i have some csv files in a folder which i am trying to edit using matlab.

my code is below

yourfolder='D:\practice\Matlab\APM3 magnet measurements\Sensormagnet1';
d=dir([yourfolder '\*.csv']);
files={d.name};
file=files(1);
fid = fopen(file,'w');

files is a variable which has list of csv files present in folder. i created a variable to get one file name out of the list and trying to open the file with the name present in the file variable.

its giving error as given below:

Error using fopen
First input must be a file name of type char, or a file identifier of type double.

Error in CSV (line 5)
fid = fopen(file,'w');

please help me on this

Answer 1

[Stephen23]

The mistake is on this line:

file=files(1);

You need to use cell array indexing, then the code will work:

file = files{1};