Re: why DateListPlot is so slow?
- To: mathgroup at smc.vnet.net
- Subject: [mg79964] Re: why DateListPlot is so slow?
- From: "Arkadiusz Majka" <arkadiusz.majka at gmail.com>
- Date: Thu, 9 Aug 2007 05:33:04 -0400 (EDT)
- References: <f9c0ae$5o4$1@smc.vnet.net> <46B99E1E.7060605@gmail.com>
Hmmm,
Here you are
DateListPlot[{{"00:00:08",153629},{"00:00:19",37200},{"00:00:30",48591},{"00:00:40",43455},{"00:00:50",38701},{"00:01:01",32449},{"00:01:11",48995},{"00:01:22",42385},{"00:01:33",38165},{"00:01:43",36008}}]
(* and beautiful plot appears...*)
Arek
On 8/8/07, Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com> wrote:
>
> Arkadiusz.Majka at gmail.com wrote:
> > Hi,
> >
> > I have a list (a time series):
> >
> > data={{00:00:30,x1},{00:01:00,x2},{00:01:30,x3},....}
> >
> > at equally spaced time intervals (30 seconds). The length od data is
> > 8100 (24 h)
> >
> > DateListPlot[data] works fine but takes 28 sec, since
> > ListPlot[data[[All,2]]] does it in less than 0.1 sec....
> >
> > Can you explain me why DateListPlot is so time consuming? Can we
> > improve it?
>
> As written, data is an invalid Mathematica expression:
>
> In[3]:= data = {{00 : 00 : 30, x1}, {00 : 01 : 00, x2}, {00 : 01 : 30,
> x3}}
>
> During evaluation of In[3]:= Syntax::sntxf: "{" cannot be followed by \
> "00:00:30,x1}".
>
> During evaluation of In[3]:= Syntax::tsntxi: "00:00:30" is \
> incomplete; more input is needed.
>
> During evaluation of In[3]:= Syntax::sntxi: Incomplete expression; \
> more input is needed.
>
> Using strings does not solve the issue either
>
> In[1]:= data = {{"00:00:30", x1}, {"00:01:00", x2}, {"00:01:30", x3}}
>
> Out[1]= {{"00:00:30", x1}, {"00:01:00", x2}, {"00:01:30", x3}}
>
> In[2]:= DateListPlot[data]
>
> During evaluation of In[2]:= DateListPlot::ntdt: The first argument \
> to DateListPlot is not a list of pairs of dates and real values or a \
> list of lists of pairs of dates and real values. >>
>
> Out[2]= DateListPlot[{{"00:00:30", x1}, {"00:01:00", x2}, {"00:01:30",
> x3}}]
>
> So the question is, "Could you please post an example of the _real_
> structure of the dataset you feed to *DateListPlot*?"
>
> --
> Jean-Marc
>