Re: Slowness in function 'open'

[Robert A. Macy]

I have WinXP with a clock speed of 600MHz and 500MB of RAM 
[going from 250 to 500 made a speed increase of over 10 to
one on big files, which makes sense] 
running the binary 2.1.50a and now 2.9.12

Using 2.1.50a 
>> load "DataSet.bin";
which is 9MB, consisting of six variables
>> save -ascii "mybigfile.txt";
found the resulting .txt file was only 18.3MB so...
>>tic;load -force "mybigfile.txt";toc*30/18.3
answer
  34.795
...not bad for a 600MHz machine, eh?  

ok so now read and compare to my new whiz bang 2.9.12...
octave-2.9.12.exe:1> tic;load "mybigfile.txt";toc*30/18.3
error: load: failed to load matrix constant
error: load: trouble reading ascii file 'mybigfile.txt'
error: load: reading file mybigfile.txt
...and nothng got loaded.  

ok so, let's retrace...
octave-2.9.12.exe:1> load "DataSet.bin";
octave-2.9.12.exe:1> save -ascii "mybigfile2.txt";
warning: save: omitting imaginary part for ASCII file
warning: save: omitting imaginary part for ASCII file
warning: save: omitting imaginary part for ASCII file
warning: save: omitting imaginary part for ASCII file
...ouch!
oh well it still generated an ascii file that was 12.4MB
            [watch the wrap arounds here]
octave-2.9.12.exe:1> tic;load -force
"mybigfile2.txt";toc*30/12.4
error: load: mybigfile2.txt: inconsistent number of columns
near line 2
error: load: unable to extract matrix size from file
'mybigfile2.txt'

NOTE: I used the up arrow key to step backwards through
history and the history suddenly turned into only two
lines, not the several I had done?!  However, ctrl-c did
reset the history and it worked properly after that.

ok, so let me convert ALL the data to real values, called
them x1, x2, x3, etc and try again.  mybigfile3.txt was
12.4MB same as the 'stripped' one, called mybigfile2.txt
       [again, watch for wraparounds]
octave-2.9.12.exe:1> save -ascii "mybigfile3.txt" x*;
octave-2.9.12.exe:1> tic;load -force
"mybigfile3.txt";toc*30/12.4
error: load: mybigfile3.txt: inconsistent number of columns
near line 935
error: load: unable to extract matrix size from file
'mybigfile3.txt'

ok, let's try a single variable...
octave-2.9.12.exe:1> x=randn(1000,2000);
octave-2.9.12.exe:1> save -ascii "mybigfile4.txt" x;
this made a file that was 32.2MB, about the right size
             [again watch for wrap arounds]
octave-2.9.12.exe:1> tic;load -force
"mybigfile4.txt";toc*30/32.2
octave-2.9.12.exe:1> 
answer
    124.22

after quitting 2.9.12, went back to 2.1.50 and tried
reading in the single variable 32.2MB file
>>tic;load -force "mybigfile.txt";toc*30/18.3
answer
  81.480
and again,
>>tic;load -force "mybigfile.txt";toc*30/18.3
answer
  81.366

So there you have it.  2.9.12 couldn't read the old text
file generated by 2.1.50a and WORSE couldn't even read its
own text file with multiple variables, AND WAS SLOWER.  

Plus, the 2.9.12 history screwed up several times more and
had to be cleared with ctrl-c

Robert