plot dates and values in python

Question

I have a file containing data as below. you see the first column is dates. I need to plot all other columns against dates in the first column. I tried to use the code below but I receive an error message. the code an error are provided.

Data

2010-01-01,1.628,0.7063157895,0,0.9216842105
2010-01-03,1.602631579,0.6901052632,0,0.9125263158
2010-01-04,1.5818947369,0.6775789474,0,0.9043157895
2010-01-05,1.5755789473,0.6716842105,0,0.9038947368
2010-01-06,1.5605263158,0.6622105263,0,0.8983157895
2010-01-07,1.5611578948,0.6608421053,0,0.9003157895
2010-01-08,1.5598947369,0.6593684211,0,0.9005263158
2010-01-09,1.5576842105,0.6569473684,0,0.9007368421
2010-01-10,1.5462105263,0.6543157895,0,0.8918947368
2010-01-11,1.5656842105,0.6666315789,0,0.8990526316
2010-01-12,1.5517894736,0.6546315789,0,0.8971578947
2010-01-13,1.5558947368,0.6551578947,0,0.9007368421
2010-01-14,1.5638947369,0.6588421053,0,0.9050526316
2010-01-15,1.5375789474,0.6432631579,0,0.8943157895
2010-01-16,1.522631579,0.6352631579,0,0.8873684211
2010-01-17,1.5056842105,0.6254736842,0,0.8802105263
2010-01-18,1.4881052632,0.6157894737,0,0.8723157895
2010-01-19,1.4889842789,0.6251948052,0,0.8637894737
2010-01-20,1.4733383459,0.6182857143,0,0.8550526316
2010-01-21,1.4507368421,0.6009473684,0,0.8497894737

Code

import csv
import datetime as dt
import matplotlib.pyplot as plt

lis1=[]
lis2=[]
lis3=[]
lis4=[]
lis5=[]

with open('/home/omar/Desktop/finall.csv', 'rU') as f:
reader=csv.reader(f, delimiter=',')
for row in reader:

    lis1.append(dt.datetime.strptime(row[0],'%Y-%m-%d'))

    lis2.append(row[1])
    lis3.append(row[2])
    lis4.append(row[3])
    lis5.append(row[4])

fig = plt.figure()
ax = fig.add_subplot(111)
ax.plot(lis1,lis2,lis3,lis4,lis5,'o-')
fig.autofmt_xdate()

plt.show()

Error

Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/lib/python2.7/dist-packages/spyderlib/widge/externalshell/sitecustomize.py", line 540, in runfile execfile(filename, namespace)
File "/home/omar/python/plot_txt.py", line 37, in <module>
    fig.autofmt_xdate()
File "/usr/lib/pymodules/python2.7/matplotlib/figure.py", line 431, in autofmt_xdate
    for label in self.axes[0].get_xticklabels():
File "/usr/lib/pymodules/python2.7/matplotlib/axes.py", line 2614, in get_xticklabels
self.xaxis.get_ticklabels(minor=minor))
File "/usr/lib/pymodules/python2.7/matplotlib/axis.py", line 1161, in get_ticklabels
    return self.get_majorticklabels()
File "/usr/lib/pymodules/python2.7/matplotlib/axis.py", line 1145, in get_majorticklabels
ticks = self.get_major_ticks()
File "/usr/lib/pymodules/python2.7/matplotlib/axis.py", line 1244, in get_major_ticks
numticks = len(self.get_major_locator()())
File "/usr/lib/pymodules/python2.7/matplotlib/dates.py", line 802, in __call__
self.refresh()
File "/usr/lib/pymodules/python2.7/matplotlib/dates.py", line 819, in refresh
dmin, dmax = self.viewlim_to_dt()
File "/usr/lib/pymodules/python2.7/matplotlib/dates.py", line 564, in viewlim_to_dt
return num2date(vmin, self.tz), num2date(vmax, self.tz)
File "/usr/lib/pymodules/python2.7/matplotlib/dates.py", line 311, in num2date
return _from_ordinalf(x, tz)
File "/usr/lib/pymodules/python2.7/matplotlib/dates.py", line 214, in _from_ordinalf
dt = datetime.datetime.fromordinal(ix)
ValueError: ordinal must be >= 1
>>> Traceback (most recent call last):
File "/usr/lib/pymodules/python2.7/matplotlib/backends/backend_qt4.py", line 374, in idle_draw
self.draw()
File "/usr/lib/pymodules/python2.7/matplotlib/backends/backend_qt4agg.py", line 154, in draw
FigureCanvasAgg.draw(self)
File "/usr/lib/pymodules/python2.7/matplotlib/backends/backend_agg.py", line 451, in draw
self.figure.draw(self.renderer)
File "/usr/lib/pymodules/python2.7/matplotlib/artist.py", line 55, in draw_wrapper
draw(artist, renderer, *args, **kwargs)
File "/usr/lib/pymodules/python2.7/matplotlib/figure.py", line 1034, in draw
func(*args)
File "/usr/lib/pymodules/python2.7/matplotlib/artist.py", line 55, in draw_wrapper
draw(artist, renderer, *args, **kwargs)
File "/usr/lib/pymodules/python2.7/matplotlib/axes.py", line 2086, in draw
a.draw(renderer)
File "/usr/lib/pymodules/python2.7/matplotlib/artist.py", line 55, in draw_wrapper
draw(artist, renderer, *args, **kwargs)
File "/usr/lib/pymodules/python2.7/matplotlib/axis.py", line 1091, in draw    ticks_to_draw = self._update_ticks(renderer)
  File "/usr/lib/pymodules/python2.7/matplotlib/axis.py", line 945, in _update_ticks
    tick_tups = [t for t in self.iter_ticks()]
  File "/usr/lib/pymodules/python2.7/matplotlib/axis.py", line 889, in iter_ticks
    majorLocs = self.major.locator()
  File "/usr/lib/pymodules/python2.7/matplotlib/dates.py", line 802, in __call__
    self.refresh()
  File "/usr/lib/pymodules/python2.7/matplotlib/dates.py", line 819, in refresh
    dmin, dmax = self.viewlim_to_dt()
  File "/usr/lib/pymodules/python2.7/matplotlib/dates.py", line 564, in viewlim_to_dt
    return num2date(vmin, self.tz), num2date(vmax, self.tz)
  File "/usr/lib/pymodules/python2.7/matplotlib/dates.py", line 311, in num2date
    return _from_ordinalf(x, tz)
  File "/usr/lib/pymodules/python2.7/matplotlib/dates.py", line 214, in _from_ordinalf
    dt = datetime.datetime.fromordinal(ix)
ValueError: ordinal must be >= 1

The traceback is formatted very bad so it is hard to read. There are multiple issues in your code at ax.plot(lis1,lis2,lis3,lis4,lis5,'o-'). 1) plot() may only plot a graph with x- and y- values. You can only plot on graph at a time. 2) plot does not accept date objects as x values. You have to put in scalars. — jochen
– jochen, Commented Jan 29, 2016 at 10:39

tmdavison · Accepted Answer · 2016-01-29 10:39:12Z

2

The error is in your plot command.

You need to repeat what is on the x axis for each field you plot on the y axis.

So change this:

ax.plot(lis1,lis2,lis3,lis4,lis5,'o-')

to this:

ax.plot(lis1,lis2,lis1,lis3,lis1,lis4,lis1,lis5,'o-')

answered Jan 29, 2016 at 10:39

tmdavison

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2 Comments

Omar Ali Over a year ago

@ tom: I had to repeat lis1. However, I need more info on giving legend and make the graph as a scatter plot

tmdavison Over a year ago

you should probably ask a new question, showing how your plot look now, and describe how you would like to change it.

Serbitar · Accepted Answer · 2016-01-29 10:43:56Z

1

try:

import csv
import datetime as dt
import matplotlib.pyplot as plt

lis1=[]
lis2=[]
lis3=[]
lis4=[]
lis5=[]

with open('/home/omar/Desktop/finall.csv', 'rU') as f:
reader=csv.reader(f, delimiter=',')
for row in reader:

    lis1.append(dt.datetime.strptime(row[0],'%Y-%m-%d'))

    lis2.append(row[1])
    lis3.append(row[2])
    lis4.append(row[3])
    lis5.append(row[4])

fig = plt.figure()
ax = fig.add_subplot(111)
ax.plot_date(lis1,lis2,'o-',
             lis1,lis3,'o-',
             lis1,lis4,'o-',
             lis1,lis5,'o-')

plt.show()

see documentation here: http://matplotlib.org/api/pyplot_api.html#matplotlib.pyplot.plot

answered Jan 29, 2016 at 10:43

Serbitar

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