Re: Bug in script for plotting

[c.]

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.