Textscan and file paths work on my MacBook, but not on Windows 7

I wrote a script on my MacBook (running MATLAB 2011a) that works just fine (in a loop, it reads a few files of test data, plots relevant parts, then repeats). I need to hand it off to my boss who runs MATLAB 2007 on a PC, but it won't run.

Inside the loop, I've been using textscan to read the data from .csv files, like this:

FID = fopen(['PEMS_event/',files{N,3}]);
event = textscan(FID,'%f %d %s',inf,'delimiter',',');
event_t = event{1};
event_ID = event{2};
fclose(FID);

where files{N,3} refers to a matrix of .csv filenames defined earlier.

The fopen command seems to work (FID is a positive integer), but 'event' is an array of empty arrays/cells.

I suspect the problem has to do with the file path, but the same problem occurred when I moved the files directly into the current directory and removed the folder 'PEMS_event/' from the path specification.

I also tried using xlsread (I understand it works well with windows, not with macs) with the file in the current directory like this:

[data text] = xlsread('bb_event_2013-08-19_15-16-09.csv');

but this just gave me an error:

??? XLSREAD unable to open file bb_event_2013-08-19_15-16-09.csv.
Undefined function or variable 'name'.

Help? I'm confused. Thanks in advance.

Answer 1

[Cedric]

For building the full path, use FULLFILE. In FOPEN, specify the permission explicitly, so you don't have to count on compatibility of default args between versions. Could you copy/paste a chunk of this file that you are trying to read, so we can check the formatSpec? For CSV files, use CSVREAD or DLMREAD instead of XLSREAD.

[Sean Hammett]

Sure, here's what the files look like:

12.290, 26, Data start
1641.048, 28, Sub-test started
2092.079, 29, Sub-test stopped
2947.900, 28, Sub-test started
3268.531, 29, Sub-test stopped
4035.932, 28, Sub-test started
4215.202, 9, Fuel reposition
4382.522, 29, Sub-test stopped
5195.953, 28, Sub-test started
5625.284, 29, Sub-test stopped
6297.775, 28, Sub-test started
6824.856, 29, Sub-test stopped
8029.087, 28, Sub-test started
8867.668, 29, Sub-test stopped

Another of the files the script opens later on is of this format:

# Description: H4_Jet_Wand_1_6-18-2013
# type cal (in 5 seconds)
# 'log' command starts logging 
log
#logging
##,## 
# ,.087,.263,13.6, ,.00381,.1,.1,.1,1,.0106
seconds,CO,CO2,PM,Flow,FlueTemp,TCpot,TC1,TC2,TC3,Voc
1.00,300,3514,436,9230,7108,65536,65536,147,65536,0
3.00,306,3340,434,9235,7103,65536,65536,147,65536,0
5.00,307,3192,434,9215,7112,65536,65536,148,65536,0

I wasn't using csvread because it can't accept non-numeric data, that is it gives an error on encountering header lines or columns of strings. With textscan I could just go through those columns or rows specifying a string format, and then look at the actual data after line 8 by issuing the command again (I'll put that chunk of code below too). If there is a workaround using dlmread or csvread, I see no reason that couldn't fix the script but I haven't gotten those functions to work either.

FIDp = fopen(['PEMs_data/',files{N,2}]);
PEMShead = textscan(FIDp,'%s %s %s %s %s %s %s %s %s %s %s',8,'delimiter',',');
PEMSdata = textscan(FIDp,'%f %f %f %f %f %f %f %f %f %f %f','delimiter',',');
fclose(FIDp);

[Sean Hammett]

My friend Julie figured it out! On my Mac, 'inf' tells textscan to go to the end of the file, but on this PC it's -1. Changing that, the script runs fine.

FID = fopen(['PEMS_event/',files{N,3}]);
event = textscan(FID,'%f %d %s',-1,'delimiter',',');
event_t = event{1};
event_ID = event{2};
fclose(FID);

Thanks for your time!

[Cedric]

Great that she found out, because I had no memory that Inf was not supported in the 2007 version!