Menu
▾
▴
Re: [Gnuplot-info] plotting 2d specifying range on 3rd dimension
|
From: Thomas S. <t.s...@fz...> - 2007-10-08 17:28:59
|
i searched through my old emails and found an old posting to
inf...@Da...
the question was:
>> How do I specify time range to generate a plot of data
>> for say time range "01/01/2000 00:00 to 01/02/2000 00:00 "
this was the answer:
> not so easy... it's a little bit tricky but it works:
> when using time data for plotting a 'set timefmt "..."' is used to tell
> gnuplot how to interpret the data. the 'set timefmt' is only useful in
> combination with 'set xdata time', that's what the manual says. it's not
> completely true, because without 'set xdata time' one can still interpret
> time
> data with 'timecolumn(.)' (not really documented, is similar to
> 'column(.)' within the
> 'using' modifier). internally gnuplot calculates time data into 'number of
> seconds since the beginning of the century', so we are lucky, the century
> has
> just started, and thus the numbers are low. so add the line:
> set timefmt "%d/%m/%Y %H:%M"
> to your script and replace the plot command by:
> plot [0:360][-5:5] [-5:5] 1,3,5, 'pol.txt' using \
> 4:(timecolumn(1)>=0?$3:1/0) t '' with lines
> (use lines to see what's happening). the trick is, allow values to be
> plotted
> only when a specific condition is fulfilled, using the ternary operator:
> if the condition is fulfilled everything between the '?' and the ':' is
> used,
> here: column 3 ($3), if it's not fulfilled what's following the ':' is
> used,
> here: 1/0 (= division by zero means 'not defined' to gnuplot, i.e. nothing
> is
> plotted).
> examples:
> 4:(timecolumn(1)>=0?$3:1/0) plots all data starting from 01/01/2000
> 00:00:00
> ('01/01/2000 00:00:00' is the second '0' of the new century)
> 4:(timecolumn(1)>0?$3:1/0) plots all data starting from 01/01/2000
> 00:00:01
> (your first datapoint will disappear)
> 4:(timecolumn(1)>(3600*6)?$3:1/0) plots all data starting from 01/01/2000
> 06:00:01
> (and the second datapoint will disappear)
> 4:(timecolumn(1)>=0?(timecolumn(1)<=(24*3600)?$3:1/0):1/0)
> (plots the data between 01/01/2000 00:00:00 and 01/02/2000 00:00:00)
>
> it's not as easy as a 'set xrange [.:.]' but there is a work-around. you
> can
> use two variables e.g. 'a' and 'b' in your plot command:
> ... using 4:(timecolumn(1)>=a?(timecolumn(1)<=b?$3:1/0):1/0) ...
> and these variables you can set in a script or at the gnuplot command
> line. for
> the last of the above examples you would write
> a = 0
> b = 24*3600
the answer was for gnuplot 3.7, so maybe some things are outdated, but the
principle is the same for gnuplot 4.x.
one more remark:
to get the 'number of seconds' for a specific date use the 'test time'
command:
gnuplot> test time "%d.%m.%Y %H:%M:%S" "08.10.2007 19:45:55"
internal = 245187955.000000 - 8/10/7::19:45:55 , wday=-1, yday=-1
convert back "08.10.2007 19:45:55" - 8/10/7::19:45:55 , wday=1, yday=280
'internal' is the number of seconds since 1.1.2000 00:00:00
Alexander_P wrote:
>
> Hello,
> i have a data file looking like this:
>
> 02:25:40 183.69 92.61 91.56 90.01 540.00 97.53
> 02:25:45 204.50 93.38 89.99 89.61 600.00 100.31
> 02:25:50 224.28 94.07 88.49 89.25 600.00 100.31
> 02:25:55 243.06 95.09 87.06 88.92 600.00 104.26
> 02:26:00 257.91 96.21 85.71 88.63 540.00 106.29
> 02:26:05 269.01 97.09 84.42 88.37 480.00 104.99
> 02:26:10 276.56 98.11 83.20 88.13 420.00 107.34
> 02:26:15 280.74 99.39 82.04 87.92 360.00 110.90
> 02:26:20 281.70 101.08 80.94 87.73 300.00 116.31
>
>
> the time is in the first collumn and i want to plot 3:4 for example
> specifying a range on the time collumn ( for example
> ["02:00:00":"03:00:00"] )
>
> i experimented with timefmt and set it to "%H:%M:%S" to match my
> timeformat but i was not able to do the 2d plot with specifying a range on
> the time... :/
>
> any help appreciated ;)
> thanks in advance
>
> Alex
>
--
View this message in context: http://www.nabble.com/plotting-2d-specifying-range-on-3rd-dimension-tf4588246.html#a13101234
Sent from the Gnuplot - User mailing list archive at Nabble.com.
|
