Re: How to display dates in plots
- To: mathgroup at smc.vnet.net
- Subject: [mg58727] Re: How to display dates in plots
- From: Peter Pein <petsie at dordos.net>
- Date: Fri, 15 Jul 2005 14:14:09 -0400 (EDT)
- References: <db7nt2$mss$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
ggroup at sarj.ca schrieb:
> I'm evaluating Mathematica v5.1 to automate some data analysis for me.
> I have one question that I have yet to find an answer (or even a clue).
> I was hoping someone here may have a good idea.
>
> I collect data sets that I want to plot in various ways versus time.
> Each record in the data sets includes a date/time string and various
> (numeric) sensor readings. I've got an ugly but effective loop to
> convert the date strings in my data files to serial time. I've been
> this serial time to plot my data. Now the question is: is there a way
> to format the plot axes to display a human readable date rather than
> the serial date?
>
> One note: Not all the data records are taken at regular intervals.
> When an event is happening on one of the sensors, we often increase the
> sampling frequency to get better resolution.
>
> Thanks very much.
>
{start, stop} = FromDate /@
{{2005, 6, 15, 13, 0, 0}, {2005, 7, 24, 17, 4, 0}};
As example: a 'weekly' sine wave
Plot[Sin[t*(2*Pi/(24*3600*7))], {t, start, stop},
Ticks -> {Table[{i, StringForm["`1`/`2`", ##1]& @@
Take[ToDate[i], {2, 3}]}, {i, start, stop, 2*24*3600}],
Automatic},
AspectRatio -> 1/8, ImageSize -> 800];
This will place tickmarks every two days and print them as month/day.
--
Peter Pein
Berlin
http://people.freenet.de/Peter_Berlin/