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Always interested in offers/projects/new ideas. Eclectic experience in fields like: numerical computing; Python web; Java enterprise; functional languages; GPGPU; SQL databases; etc. Based in Santiago, Chile; telecommute worldwide. CV; email.

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Plotting Data from Postgres

From: "andrew cooke" <andrew@...>

Date: Sun, 31 Aug 2008 13:16:04 -0400 (CLT)

If PL/R looks too complicated -
http://www.varlena.com/GeneralBits/Tidbits/bernier/art_66/graphingWithR.html
- then from google hits it looks like gnuplot is the best (ie most
popular) option for plotting data in Postgres.

In postgres:
\t (do this only once - it toggles)
\o plot.txt
select count(*), distance from nearest_6_100 group by distance order by
distance;
\o

In gnuplot:
set term dumb 70 24
plot 'plot.txt'

  120 ++--------A---------+----------+---------+---------+--------++
      +         +         +          +         + 'plot.txt'   A    +
      |         AA                                                 |
  100 ++      AAAAA                                               ++
      |       AAA AA                                               |
      |        AAA A A                                             |
      |       A  AAA                                               |
   80 ++      AA AAAA                                             ++
      |       A A AAA                                              |
      |     AAA     AA                                             |
   60 ++    AAA     A                                             ++
      |    AAAA      A                                             |
      |    AAA      A A                                            |
   40 ++   AA        AAA                                          ++
      |    A          AA                                           |
      |   AA          AAA                                          |
      |   AA           AA                                          |
   20 ++ AAA           AAA                                        ++
      | AAA              AAA A                                     |
      +AAA      +        AAAAAA  AA  +     A   AAAAAAAAAA+A        +
    0 AAA-------+---------+-AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA-----++
      0        100       200        300       400       500       600


Andrew

With Separator

From: "andrew cooke" <andrew@...>

Date: Sun, 31 Aug 2008 13:28:17 -0400 (CLT)

Ooops.  That plotted only the first column.

What I wanted was...

In postgres:
\t
\o plot.txt
select distance, count(*) from nearest_6_100 group by distance order by
distance; (note swapped order)
\o

In gnuplot:
set datafile separator '|'
set log x
set xtics (1000,2000,3000,5000,10000)
plot [1000:10000] 'plot.txt'


  120 ++----------------A----------+-------------+----------------++
      +                 +          +             'plot.txt'   A    +
      |                 A                                          |
  100 ++                A                                         ++
      |                 A                                          |
      |                 A                                          |
      |                 AA                                         |
   80 ++                AA                                        ++
      |                 AA                                         |
      |                 AA                                         |
   60 ++               AAA                                        ++
      |                AAA                                         |
      |                AAA                                         |
   40 ++               AAA                                        ++
      |                A A                                         |
      |                A A                                         |
      |                A A                                         |
   20 ++               A A                                        ++
      |                A AA                                        |
      +                A+AA        + A          A+                 +
    0 ++--------------AA+-A--------+AAA---AA-AAAAA----------------++
     1000              2000       3000          5000             10000

(data have changed since last post).

Andrew

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