matplotlib-users

[Matplotlib-users] Labeling X-axis with time data

[pgb205 <pau...@op...>]

et say i have two arrays
time_array=[00:00:00,00:00:10...17:59:50,18:00:00]
and
data_array=[1,12..34,2]
both of them with the same number of elements.
I want to graph data_array on y axis vs time_array on x_axis.
However, I'm unable to do this using matplotlib because it complains
time_array is not in numeric form.
I guess I should do plot=(data_array) and somehow mark the x axis with
time_array data at periodic intervals. Any suggestion on how to mark x-axis
with times?

thanks
-- 
View this message in context: http://www.nabble.com/Labeling-X-axis-with-time-data-tp23819363p23819363.html
Sent from the matplotlib - users mailing list archive at Nabble.com.

Re: [Matplotlib-users] Labeling X-axis with time data

[Sandro T. <mo...@de...>]

hi,

On Mon, Jun 1, 2009 at 20:08, pgb205 <pau...@op...> wrote:
>
> et say i have two arrays
> time_array=[00:00:00,00:00:10...17:59:50,18:00:00]
> and
> data_array=[1,12..34,2]
> both of them with the same number of elements.
> I want to graph data_array on y axis vs time_array on x_axis.
> However, I'm unable to do this using matplotlib because it complains
> time_array is not in numeric form.
> I guess I should do plot=(data_array) and somehow mark the x axis with
> time_array data at periodic intervals. Any suggestion on how to mark x-axis
> with times?

Plotting data against time needs this:

- x data values has to be datetime objects (so you have to convert to that)
- you have to use plot_data() instead of plot()
- adjust X axes formatter and locato with date formatter and locator

hope this reference will guide you trhu mpl documentation to have a
working program; in the gallery in the website you can also find an
example for date plotting.

Cheers,
-- 
Sandro Tosi (aka morph, morpheus, matrixhasu)
My website: http://matrixhasu.altervista.org/
Me at Debian: http://wiki.debian.org/SandroTosi

Re: [Matplotlib-users] Labeling X-axis with time data

[Sandro T. <mo...@de...>]

Better keep the list in the loop ;)

On Tue, Jun 2, 2009 at 21:20, C M <cmp...@gm...> wrote:
> On Tue, Jun 2, 2009 at 1:56 PM, Sandro Tosi <mo...@de...> wrote:
>> - x data values has to be datetime objects (so you have to convert to that)
>> - you have to use plot_data() instead of plot()
>
> OP, note that is a typo for plot_date(), not plot_data().
>
> For converting dates to numbers, also there is in matplotlib.dates
> the date2num function.

-- 
Sandro Tosi (aka morph, morpheus, matrixhasu)
My website: http://matrixhasu.altervista.org/
Me at Debian: http://wiki.debian.org/SandroTosi