Problem with load function for ASCII files

Hi,

I'm unable to load some ASCII files in R2012a. I can open the file in the editor and confirm it's formatted properly (rectangular array of floating point numbers, comments at top of file begun with '%'), so it's not a problem with permissions. When I try to load() the files it returns empty values.

the files look like this, roughly:

%  temp.txt            
81  0.3  2.364483884  0.075  0.045  0  0  2
81  0.3  2.389637968  0.075  0.045  0  0  2
81  0.3  2.739698969  0.075  0.045  0  0  2
81  0.3  2.662140543  0.075  0.045  0  0  2

...

This is a transcript of me trying to load the file and confirm it's loaded.

>> load temp.txt
>> whos
  Name      Size            Bytes  Class     Attributes

    temp      0x0                 0  double              

>>

There are no error messages, as you can see, just returning an empty matrix. No idea how to proceed from here.

[Walter Roberson]

I copied that exact data; it worked for me in R2008b.

[per isakson]

Is "% temp.txt" the first line of the file?

[Norm Nelson]

yes, the first line is a comment

[Norm Nelson]

Also, these files opened just fine in R2008 ... !

[Norm Nelson]

Unfortunately, this will require me to revise a large number of scripts that currently use load() to load ascii files. Why doesn't load() work for these files any more, I guess is my real question. Thanks!

Answer 1

[Norm Nelson]

importdata() works best: reads the files correctly without me having to edit the files. Thanks, per.

I'm baffled as to why MATLAB's behavior has changed with regards to something as fundamental as load(). This will mean a huge amount of work to correct. Oh well.

[per isakson]

Is it really the comment line, which causes the failed read?

Answer 2

[per isakson]

Did you try

dlmread
Read ASCII-delimited file of numeric data into matrix

.

--- Cont. ---

I cannot make dlmread handle comment lines - regardless of how I set the range.

.

--- Revisit the OP's question ---

I find it difficult to remember all the details of all the functions, which read ascii-data. When faced with a failed read it is too easy to jump into the wrong conclusions. I need a "selection guide". Nevermind, I copy&pasted the five lines of OP into cssm.txt and cssm.mat. The two files are thus identical but for the extension. Then I run (R2012a, 64bit, Windows7)

    load cssm.txt           % ok
    load cssm.mat           % error
    load cssm.mat -ascii    % ok
    importdata cssm.txt     % ok
    importdata cssm.mat     % error

.

load cssm.mat caused the error message

    Error using load
    Unable to read MAT-file h:\m\cssm\cssm.mat: not a binary MAT-file.
    Try LOAD -ASCII to read as text.

and importdata cssm.mat caused the warning

    Warning: File contains uninterpretable data. 
    > In importdata at 144

and returned an empty result

    ans = 
            data: []
        textdata: {}

Yes, I have checked twice that the correct data is assign in the "ok-cases".

Thus, I believe there is some other problem with the file of OP.

[Norm Nelson]

yes, this works, if I strip the comments from the file

[Walter Roberson]

dlmread() has an option to specify range.

You could put your own load() routine earlier in the path. Or you could do a batch edit to change load to your own routine name (a safer approach.)