Re: [Gnuplot-info] abort/continue plotting on error

[walter h. <wh...@bf...>]

Am 27.04.2013 16:26, schrieb seb_kramm:
> On 04/27/2013 05:54 AM, Ethan A Merritt wrote:
>> On Friday, 26 April 2013, seb_kramm wrote:
>>> Currently, when chaining different plot commands in a script, it seems that gnuplot
>>> aborts when encountering a error (unreadable data file, in my case).
>>> Is there any way to tell gnuplot not to abort and to move on to the next 'plot'
>>> command ? I searched the manual but found nothing about error handling.
>>
>> There is no general mechanism for continuing to execute a script after an error.
> 
> Thanks, indeed this would be a non trivial thing to adress.
> 
>>> The situation is as follows: I have many plots to draw from many computer-generated
>>> data files. The script file is itself generated. Now, some data files are ill formed
>>> or non-existent, due to some experimental error (say, the program that generates the
>>> data crashes).
>>> But I would like to have the plots for all the other datafiles.
>>
>> How about
>>
>>    expected_file = "filename"
>>    stat = system("wc ".expected_file)
>>    if (stat ne "") {
>>       plot expected_file
>>    }
>>
>> If you want to test for a file that exists but is too short to
>> contain the expected data:
>>
>>    stat = system("wc ".expected_file)
>>    if (stat ne ""  &&  int(word(stat,1)) > min_size) {
>>      plot expected_file
>>    }
> 
> Woaw, really clever trick, I didn't realize you could call shell commands from within 
> gnuplot. I will implement this, but the second version will not apply, as my data 
> files don't always have the same number of data points.
> Thank you Ethan.
> 
> Sebastien Kramm
> 
> 
hi,
just in case you simply want to check that you have a filesize > 0
test -s FILE would do the trick.
An other funny trick is to use stat.
stat -c "%s" FILE
It read the file system information instead of scanning the whole file.

just my 2 cents.
re,
 wh