Re: Postgres and GnuPlot

[Mila Boldareva <me@xxxxxxxxxxxxx>]

> Has anybody tried using gnuplot to plot results from queries; there
> are some suggestions given in PostgreSQL Developer's Handbook but i
> have not any luck so far!
> Any pointers as how to send results from queries straight to a simple
> plotting utility (ex:gnuplot)!
>
>  
I use a text file as an intermediary.
You only need to slightly modify (postgres output) and/or (gnuplot 
input) options:

for postgres, put something like this before the query:

\pset null '?9'
--  or other impossible beginning char to indicate missing values correctly

\t
--  will show only data rows

\f '\t'  
-- make sure columns are tab-separated

-- don't align the output:
\a

Instead of the last two, you may change in the gnuplot script:

set datafile separator '|'

Additionally, let gnuplot know your missing columns:
set datafile missing '?'

Hope this helps.

---------------------------(end of broadcast)---------------------------
TIP 6: Have you searched our list archives?

              http://archives.postgresql.org