HELP? Looping and saving

Hi, I would appreciate some code to assist me with the following:

I have 90 of these .cvs files:

They look like this inside (I only need the numbers from ColumnB to ColumnE and from row6 down):

I need them brought into Matlab one by one so that they can be used in these formulas:

So Trial01 needs to go through these equations, then the graph(s) outputted and saved, before the next set of data is brought in and the same done again. Each set of data also needs to saved as a variable.

Please can anyone give me some code that can do this please. If there any any questions please don't hesitate to ask.

Thanks again

P.s Please don't point me to any other pages as I have looked round and tried and can't manage to do it

[dpb]

And just what have you managed to do?

[BOB]

not make it loop through correctly. It loops through but doesn't give me the data and overwrites itself each time

[dpb]

Show your work...paste code, not screen shots and format correctly so it's legible.

It seems like I've done this work for two others over and over just in the last week or so...what's different here than there? I KNOW I showed you how to read the files in another thread where you added comments inline of the original poster. Doesn't seem like we get anywhere but rehash same ol' stuff...

[BOB]

yes, you told me to use this but I just get errors.

    d=dir('*.csv');   % return the list of csv files
for i=1:length(d)
  m{i}=textread(d(i).name,'','headerlines',5);   % put into cell array
end

[Image Analyst]

dpb, you mean like here http://www.mathworks.com/matlabcentral/answers/?search_submit=answers&query=trial01&term=trial01.

BOB, please read over those. The file is not the flavor of CSV that MATLAB likes so you have to take special actions that are spelled out in those prior posts (which includes posts from you by the way).

[dpb]

Actually, I didn't see the one I was thinking of, IA; maybe it was at cs-sm instead? I forget.

Answer 1

[dpb]

Anyway, BOB, how did you manage to create the .csv files that the first column is empty? The easiest solution would be to fix that problem.

To get textread to read the file you have to add the explicit delimiter keyword to let it know what to do with the leading ',' --

m{i}=textread(d(i).name,'','headerlines',5,'delimiter',',');

Alternatively, you could try importdata--on a quick test here it seemed to be able to handle the missing values returning a column of NaN in its place.

Or, use xlsread, I wasn't aware prior to now it would handle a .csv file but it was happy; skipping the first column. See doc for each of the above functions for details.

My initial response was for ease of use with a well-formed data file; as noted ADDENDUM

BTW, as IA noted, you're asking question very similar to two other posters in the file naming convention is the same and the code you show is similar in ascertaining a height from some recorded time history velocity and acceleration data it appears.

BUT, the content of the file you're showing above is totally incompatible with that assignment/processing. Looks to me like you're reading the files for a different assignment or have glommed on to the wrong piece of sample code for the data you do have.

[BOB]

Hi, thanks for the response.

I didn't create the .csv viles, I just got given them.

I forgot to mention, I am a novice at matlab and don't really have much idea what I am doing.

How should I go about using textread to skip this first comma character and read the rest into an array?

[dpb]

Use either of the format strings I gave above. But, why must you use textread when I point out two other alternatives that could handle the problem files.

I'd tell whoever gave you the files to fix 'em...

ERRATUM:

Using the 'delimiter' option in textread to indicate the comma-delimited file is adequate.

Answer 2

[dpb]

Oh, just dawned on me...

>> type bob.csv   % a very short sample file I made up...
,0,7.7,11.1,-812.2
,1,8.2,11.1,-812.5

>> textread('bob.csv','','delimiter',',')
ans =
       0         0    7.7000   11.1000 -812.2000
       0    1.0000    8.2000   11.1000 -812.5000

Telling it the specific delimiter is the help textread needs to handle the missing column...of course, your actual file will need the proper 'headerlines' count, too.