Re: Bug in script for plotting

[Ben Abbott]

On Feb 8, 2013, at 4:58 PM, c. wrote:

> On 8 Feb 2013, at 20:41, Ben Abbott <address@hidden> wrote:
> 
>> On Feb 8, 2013, at 7:41 AM, c. wrote:
>> 
>>> On 8 Feb 2013, at 01:59, Ben Abbott <address@hidden> wrote:
>>> 
>>>> On Feb 7, 2013, at 5:28 PM, stn wrote:
>>>> 
>>>>> Hi,
>>>>> 
>>>>> this is kind of irritating. It has also probably been discussed before.
>>>>> 
>>>>> 
>>>>> The plot-command works fine, the plot appears as expected, but on the 
>>>>> terminal there is a message
>>>>> 
>>>>> gnuplot> nset obj 1;
>>>>>      ^
>>>>>      line 0: invalid command
>>>>> 
>>>>> 
>>>>> After lots of googling and some grepping I found this line in 
>>>>> /usr/local/share/octave/3.6.3/m/plot/private/__go_draw_axes__.m
>>>>> 
>>>>> Only there it says "unset obj". More specifically it says "fputs 
>>>>> (plot_stream, "unset obj 1; \\\n");"
>>>>> 
>>>>> The problem can be solved by replacing every occurence of "unset obj" in 
>>>>> the script with " unset obj".
>>>>> 
>>>>> It would appear that the function fputs() does not work correctly and 
>>>>> truncates the first character of this string. The solution mentioned 
>>>>> above simply adds a space-character, that is then truncated.
>>>>> 
>>>>> I would like to suggest checking the matter.
>>>>> 
>>>>> Best regards, stn
>>>> 
>>>> I've seen this mentioned before, but I do not get this error.  For 
>>>> example, each of the following work for me.
>>>> 
>>>>    plot (rand (3))
>>>>    surf (peaks ())
>>>>    contour (peaks ())
>>>> 
>>>> I'm using gnuplot 4.6 patchlevel 1 
>>>> 
>>>> Can you tell us what version of gnuplot you are using (just in case that 
>>>> is involved in some way).  Also, can you provide a short script that 
>>>> produces the error for you so that we may try to duplicate it?
>>>> 
>>>> Ben
>>> 
>>> Ben,
>>> 
>>> I run the development Octave version, I have gnuplot 4.6 patch level 1 
>>> (installed via macports) and XQuartz 2.7.4 on OSX 10.8.2.
>>> I can consistently reproduce the same issue reported by stn as follows:
>>> 
>>> 1) stop XQuartz
>>> 2) plot (randn (3))
>>> 
>>> the issue can be simply worked around by adding a space in front of all 
>>> instances of "unset obj 1" as stn suggested, it seems the first character 
>>> in sent to the pipe is getting lost somehow …
>>> 
>>> c.
>> 
>> Carlo,
>> 
>> I produced a plot-stream by ...
>> 
>>      plot (rand (3))
>>      drawnow ("aqua", "/dev/null", false, "debug.gp")
>> 
>> The "unset obj 1" command comes at the end of binary data record, whose 
>> ending looks like below in vi.
>> 
>> @@@@@@@@@@@@ @ @"@"@address@hidden@unset obj 1;
>> 
>> I'm thinking the problem may be with the binary record (not with the unset 
>> command).
>> 
>> Perhaps some padding should be added after each binary record?  This may 
>> just break things (works for me), but does the diff below eliminate the 
>> problem for you?
> 
> Yes, it does.

Ok. I pushed a changeset

        http://hg.savannah.gnu.org/hgweb/octave/rev/1e35b64ac31a

Ben