[LON-CAPA-admin] xtics and gnuplot

[Stuart Raeburn]

Hi Hon-Kie,

> A strange thing happen with gnuplot and xtics (running on 2.10.1). When
> using the line below, the graph is not generated or printed.

If you have updated your server to LONCAPA-prerequisites rev 1.23 (for  
LON-CAPA 2.11.0) that will have updated gnuplot from rev 4.2 to rev 4.4.

Unfortunately, a change between those two versions of gnuplot results  
in a gnuplot error when creating a plot in which either the xtics or  
ytics tags have been included, and location has been set to "axis",  
(for the case where you are running LON-CAPA 2.10.1 with gunplot 4.4).

You can display the version of gnuplot you have using:

gnuplot -V

A change was made to lonplot.pm (included in 2.11.0) to accommodate  
this gnuplot change.

If you are running LON-CAPA 2.10.1, and the version of gnuplot  
installed is 4.4 or later, and you do not plan to update to 2.11.0  
immediately, then you should replace the version of lonplot.pm (1.152)  
shipped with 2.10.1 with a modified version (1.152.6.1), which  
includes the patch for xtics/ytics location=axis support for gnuplot 4.4

 From the command line, use the command (all one one line):

wget -O /home/httpd/lib/perl/Apache/lonplot.pm  
'http://source.loncapa.org/cgi-bin/cvsweb.cgi/~checkout~/loncom/xml/lonplot.pm?rev=1.152.6.1;content-type=text/plain'

then, depending on Linux distro:

/etc/init.d/httpd reload      (CentOS, Scientific Linux, RedHat, Fedora)

or

/etc/init.d/apache2 reload  (Ubuntu, SLES, SuSE)


Stuart Raeburn
LON-CAPA Academic Consortium


Quoting "H. K. Ng" <hkng at fsu.edu>:

> Hi,
>
> A strange thing happen with gnuplot and xtics (running on 2.10.1). When
> using the line below, the graph is not generated or printed. On the web it
> says "dynamically generated ..." but no graphics and when printing, it
> complains about "Cannot determine the size of graphics ..." presumably
> because the eps was not generated.
>
> <xtics minorfreq="1" location="axis" mirror="off" end="16" increment="2"
> start="0" />
>
> However, if I use the following line (location of tics changed to border),
> it displays on the web and print just fine.
>
> <xtics minorfreq="1" location="border" mirror="off" end="16" increment="2"
> start="0" />
>
> I tried to look for error messages but could not locate any. Any clue what
> is causing this? The problems display properly - it happen in the last
> couple of days.
>
> Thanks,
> -hk