Re: matplotlib: Plotting a graph against time

2008-07-20 Thread arsyed
On Jul 19, 3:09 pm, Durand [EMAIL PROTECTED] wrote:
 Hi,

 I'm trying to plot a simple graph against date or time using matplotlib. I've 
 read about date_plot but I'm not really sure how to use it. At the moment, I 
 have some data arranged into lists, where list1 contains x values (time) and 
 list2 contains y values just like is needed for the normal plot function. The 
 time values are simply the output of datetime.date.today(), etc which I don't 
 mind changing the format of.

 My question is, how do I plot the graph with list1 on the x axis and list2 on 
 the y axis. Using plot and unixtime I get a very ugly scale as is to be 
 expected so I want to know how to use the date_plot function efficiently. At 
 the moment, I'm only concerned about the actual plotting but help with 
 Locater Ticks (Months and Years) is also very appreciated.

 Thanks a lot!


I'm not sure if this is what you're looking for, but here's a quick
sample that uses plot_date to plot some random values.

import pylab, random
from datetime import datetime, timedelta

today = datetime.now()

dates = [today + timedelta(days=i) for i in range(10)]
values = [random.randint(1, 20) for i in range(10)]
pylab.plot_date(pylab.date2num(dates), values, linestyle='-')


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Re: matplotlib: Plotting a graph against time

2008-07-20 Thread Durand
On Jul 20, 8:55 am, arsyed [EMAIL PROTECTED] wrote:
 On Jul 19, 3:09 pm, Durand [EMAIL PROTECTED] wrote:

  Hi,

  I'm trying to plot a simple graph against date or time using matplotlib. 
  I've read about date_plot but I'm not really sure how to use it. At the 
  moment, I have some data arranged into lists, where list1 contains x values 
  (time) and list2 contains y values just like is needed for the normal plot 
  function. The time values are simply the output of datetime.date.today(), 
  etc which I don't mind changing the format of.

  My question is, how do I plot the graph with list1 on the x axis and list2 
  on the y axis. Using plot and unixtime I get a very ugly scale as is to be 
  expected so I want to know how to use the date_plot function efficiently. 
  At the moment, I'm only concerned about the actual plotting but help with 
  Locater Ticks (Months and Years) is also very appreciated.

  Thanks a lot!

 I'm not sure if this is what you're looking for, but here's a quick
 sample that uses plot_date to plot some random values.

 import pylab, random
 from datetime import datetime, timedelta

 today = datetime.now()

 dates = [today + timedelta(days=i) for i in range(10)]
 values = [random.randint(1, 20) for i in range(10)]
 pylab.plot_date(pylab.date2num(dates), values, linestyle='-')

Oooh, this is almost what I want but I'm not really sure how I'd
incorporate this into real dates...
If I have a list of dates like ['2008-07-18 14:36:53.494013',
'2008-07-20 14:37:01.508990', '2008-07-28 14:49:26.183256'], how would
I convert it to a format that pylab can understand? When I tried
type(datetime.now()) it gave me datetime.datetime whereas the objects
in this list are strings...Am I doing something wrong here?
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matplotlib: Plotting a graph against time

2008-07-19 Thread Durand
Hi,

I'm trying to plot a simple graph against date or time using matplotlib. I've 
read about date_plot but I'm not really sure how to use it. At the moment, I 
have some data arranged into lists, where list1 contains x values (time) and 
list2 contains y values just like is needed for the normal plot function. The 
time values are simply the output of datetime.date.today(), etc which I don't 
mind changing the format of.

My question is, how do I plot the graph with list1 on the x axis and list2 on 
the y axis. Using plot and unixtime I get a very ugly scale as is to be 
expected so I want to know how to use the date_plot function efficiently. At 
the moment, I'm only concerned about the actual plotting but help with Locater 
Ticks (Months and Years) is also very appreciated.

Thanks a lot!
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