I am trying to plot information against dates. I have a list of dates in the format "01/02/1991".
I converted them by doing the following:
x = parser.parse(date).strftime('%Y%m%d'))
which gives 19910102
Then I tried to use num2date
import matplotlib.dates as dates
new_x = dates.num2date(x)
Plotting:
plt.plot_date(new_x, other_data, fmt="bo", tz=None, xdate=True)
But I get an error. It says "ValueError: year is out of range". Any solutions?
You can do this more simply using plot() instead of plot_date().
First, convert your strings to instances of Python datetime.date:
import datetime as dt
dates = ['01/02/1991','01/03/1991','01/04/1991']
x = [dt.datetime.strptime(d,'%m/%d/%Y').date() for d in dates]
y = range(len(x)) # many thanks to Kyss Tao for setting me straight here
Then plot:
import matplotlib.pyplot as plt
import matplotlib.dates as mdates
plt.gca().xaxis.set_major_formatter(mdates.DateFormatter('%m/%d/%Y'))
plt.gca().xaxis.set_major_locator(mdates.DayLocator())
plt.plot(x,y)
plt.gcf().autofmt_xdate()
Result:
I have too low reputation to add comment to #bernie response, with response to #user1506145. I have run in to same issue.
The answer to it is an interval parameter which fixes things up
import matplotlib.pyplot as plt
import matplotlib.dates as mdates
import numpy as np
import datetime as dt
np.random.seed(1)
N = 100
y = np.random.rand(N)
now = dt.datetime.now()
then = now + dt.timedelta(days=100)
days = mdates.drange(now,then,dt.timedelta(days=1))
plt.gca().xaxis.set_major_formatter(mdates.DateFormatter('%Y-%m-%d'))
plt.gca().xaxis.set_major_locator(mdates.DayLocator(interval=5))
plt.plot(days,y)
plt.gcf().autofmt_xdate()
plt.show()
As #KyssTao has been saying, help(dates.num2date) says that the x has to be a float giving the number of days since 0001-01-01 plus one. Hence, 19910102 is not 2/Jan/1991, because if you counted 19910101 days from 0001-01-01 you'd get something in the year 54513 or similar (divide by 365.25, number of days in a year).
Use datestr2num instead (see help(dates.datestr2num)):
new_x = dates.datestr2num(date) # where date is '01/02/1991'
Adapting #Jacek Szałęga's answer for the use of a figure fig and corresponding axes object ax:
import matplotlib.pyplot as plt
import matplotlib.dates as mdates
import numpy as np
import datetime as dt
np.random.seed(1)
N = 100
y = np.random.rand(N)
now = dt.datetime.now()
then = now + dt.timedelta(days=100)
days = mdates.drange(now,then,dt.timedelta(days=1))
fig = plt.figure()
ax = fig.add_subplot(111)
ax.plot(days,y)
ax.xaxis.set_major_formatter(mdates.DateFormatter('%Y-%m-%d'))
ax.xaxis.set_major_locator(mdates.DayLocator(interval=5))
ax.tick_params(axis='x', labelrotation=45)
plt.show()
Related
I have an x-axis labels of timedelta64[ns] coming out as:
0 days 12:01:13.165040
How can I achieve the following format if there's only 1 day?:
12:01:13
If there's more than one day, I need the following format:
2018.11.27
I've been successful in modifyng the labels by making a function and then calling it with:
ax.xaxis.set_major_formatter(plt.FuncFormatter(xaxisFormat))
But I don't know how to exactly go about formatting them.
You could set the respective formatter in dependence of the limits of the plot. This could look as follows.
import numpy as np
import datetime as dt
import matplotlib.pyplot as plt
from matplotlib.dates import DateFormatter, HourLocator, DayLocator
def plot_something(h, ax=None):
td = np.arange(0,h, np.timedelta64(1, "h"))
y = np.sin(np.linspace(0,h,len(td)))
t = np.datetime64("2018-11-27") + td
(ax or plt.gca()).plot(t, y)
fig, axes = plt.subplots(nrows=4)
plot_something(16, ax=axes[0])
plot_something(24, ax=axes[1])
plot_something(40, ax=axes[2])
plot_something(72, ax=axes[3])
def ticking(ax):
d = np.diff(ax.get_xlim())
if d <= 1:
ax.xaxis.set_major_formatter(DateFormatter("%H:%M:%S"))
elif d <= 2:
ax.xaxis.set_major_locator(HourLocator(byhour=(0,6,12,18)))
ax.xaxis.set_major_formatter(DateFormatter("%H:%M:%S"))
else:
ax.xaxis.set_major_locator(DayLocator())
ax.xaxis.set_major_formatter(DateFormatter("%Y.%m.%d"))
for ax in axes.flat:
ticking(ax)
fig.tight_layout()
plt.show()
I want to draw a graphic with using datas in datetime format as xaxis, but the process lasts very, very, extremly long, over 30 mins there is still no graphic. But once I apply datas in another column, the graphic will occur very soon. All the datas' formats are 'list'.
I'm confused about that, since they are all in the same format, why I can't draw the graphic out using the datetime formate as xaxis??
here is my code, I cherish all your time and help!
from matplotlib import pyplot as plt
import csv
names = []
x = []
y = []
names=[]
with open('all.csv','r') as csvfile: #this csv file contains over 16000 datas
plots= csv.reader(csvfile,delimiter=',')
for row in plots:
x.append(row[1]) #row1 is the datetime format data
y.append(row[2])
print(x,y)
plt.plot(x,y)
plt.show()
Lines of my csv file look something like:
2016/05/02 10:47:45,14.1,20.1,N.C.,170.7,518.3,-1259,-12.61,375.8,44.92,13.76,92.74,132.6,38.86,165.3,170.9,311.5,252.3,501.2,447.2,378.4,35.48,7.868,181.2,
I want the first column as xaxis and the following colums as yaxis...
and the y axis doesn't change, no matter how I change the y axis limit.
import matplotlib.pyplot as plt
import numpy as np
import pandas as pd
df = pd.read_csv('all.csv')
x = df.iloc[:,1]
y = df.iloc[:,3]
x = pd.to_datetime(x)
plt.figure(num=3, figsize=(15, 5))
plt.plot(x,y)
my_y_ticks = np.arange(0, 40, 10)
plt.xticks(rotation = 90)
plt.show()
I havent understood exactly what you mean with all the datas' format are list, but I think you could use something like this:
import matplotlib.pyplot as plt
import pandas as pd
df = pd.read_csv('all.csv')
x = df.iloc[:,0]
y = df.iloc[:,1]
x = pd.to_datetime(x)
plt.plot(x,y)
plt.show()
Maybe showing some rows can be useful
EDIT:
import matplotlib.pyplot as plt
import matplotlib.dates as mdates
df = pd.read_csv('all.csv')
x = df.iloc[:,0]
y = df.iloc[:,1]
x = pd.to_datetime(x, format="%Y/%m/%d %H/%M/%S") #if the format is different, change here
fig, ax = plt.subplots()
ax.plot(x, y)
xfmt = mdates.DateFormatter("%Y/%m/%d %H:%M:%S")
ax.xaxis.set_major_formatter(xfmt)
plt.xticks(rotation=70)
plt.show()
I have the following sample codes:
import pandas as pd
import matplotlib.pyplot as plt
dates = ['01/02/2007 00:02:00','01/02/2007 00:04:00','02/02/2007
00:02:00','02/02/2007 00:04:00']
x = pd.to_datetime(dates, format='%d/%m/%Y %H:%M:%S')
y = [0.32,0.33,0.32,0.34]
plt.plot(x,y)
I would like to have the xtick to be just 'Thu' for 01/02/2007 and 'Fri' for 02/02/2007. What is the best possible way to do that?
One possible solution is to change the X-axis format:
import pandas as pd
import matplotlib.pyplot as plt
import matplotlib.dates as mdates
dates = ['01/02/2007 00:02:00','01/02/2007 00:04:00','02/02/2007 00:02:00','02/02/2007 00:04:00']
x = pd.to_datetime(dates, format='%d/%m/%Y %H:%M:%S')
y = [0.32,0.33,0.32,0.34]
fig, ax = plt.subplots()
ax.plot(x,y)
yearsFmt = mdates.DateFormatter('%a')
ax.xaxis.set_major_formatter(yearsFmt)
plt.show()
The key idea is to get the dayofweek from the DateTime object, like: x.dayofweek. This returns the numeric dayofweek. We can easily get the corresponding name np.array(['Mon','Tue','Wed','Thu','Fri','Sat', 'Sun'])[x.dayofweek]
import pandas as pd
import matplotlib.pyplot as plt
import numpy as np
dates = ['01/02/2007 00:02:00','01/02/2007 00:04:00','02/02/2007 00:02:00','02/02/2007 00:04:00']
x = pd.to_datetime(dates, format='%d/%m/%Y %H:%M:%S')
x_d = np.array(['Mon','Tue','Wed','Thu','Fri','Sat', 'Sun'])[x.dayofweek]
y = [0.32,0.33,0.32,0.34]
ser = pd.Series(y, index=x_d)
ser.plot()
I am plotting two pandas series. The index is a date (1-1 to 12-31)
s1.plot()
s2.plot()
pd.plot() interprets the dates and assigns them to axis values as such:
I would like to modify the major ticks to be the 1st of every month and minor ticks to be the days in between
This works:
%matplotlib notebook
import matplotlib as mpl
import matplotlib.dates as mdates
import matplotlib.pyplot as plt
import pandas as pd
df = pd.read_csv('data.csv')
df['Date'] = pd.to_datetime(df['Date']).dt.strftime('%m-%d')
s2014max = df2014.groupby(['Date'], sort=True)['Data_Value'].max()/10
s2014min = df2014.groupby(['Date'], sort=True)['Data_Value'].min()/10
#remove the leap day and convert to datetime for plotting
s2014min = s2014min[s2014min.index != '02-29']
s2014max = s2014max[s2014max.index != '02-29']
dateslist = s2014min.index.tolist()
dates = [pd.datetime.strptime(date, '%m-%d').date() for date in dateslist]
plt.figure()
ax = plt.gca()
ax.xaxis.set_major_locator(mdates.MonthLocator())
ax.xaxis.set_minor_locator(mdates.DayLocator())
monthFmt = mdates.DateFormatter('%b')
dayFmt = mdates.DateFormatter('%d')
ax.xaxis.set_major_formatter(monthFmt)
ax.xaxis.set_minor_formatter(dayFmt)
ax.tick_params(direction='out', pad=15)
s2014min.plot()
s2014max.plot()
This results in no ticks:
A possible way is to use matplotlib for plotting the dates instead of pandas.
import pandas as pd
import matplotlib.pyplot as plt
import matplotlib.dates as mdates
import numpy as np
dates = pd.date_range("2016-01-01", "2016-12-31" )
y = np.cumsum(np.random.normal(size=len(dates)))
df = pd.DataFrame({"Dates" : dates, "y": y})
fig, ax = plt.subplots()
ax.plot_date(df["Dates"], df.y, '-')
ax.xaxis.set_major_locator(mdates.MonthLocator())
ax.xaxis.set_minor_locator(mdates.DayLocator())
monthFmt = mdates.DateFormatter('%b')
ax.xaxis.set_major_formatter(monthFmt)
plt.show()
You were so close! All you needed to do was add the formatters similar to how the other answer did it. Here is a working sample similar to your code (note I did mine in ipython notebook hence the %matplotlib inline).
%matplotlib inline
import pandas as pd
import matplotlib.pyplot as plt
import matplotlib.dates as mdates
from datetime import datetime, timedelta
from random import random
y = [random() for i in range(25)]
x = [(datetime.now() - timedelta(days=i)) for i in range(25)]
x.reverse()
s = pd.Series(y, index=x) # NOTE: S, not df, since you said you were using series
# format the ticks
ax = plt.gca()
ax.xaxis.set_major_locator(mdates.MonthLocator())
ax.xaxis.set_minor_locator(mdates.DayLocator())
monthFmt = mdates.DateFormatter('%b')
dayFmt = mdates.DateFormatter('%d')
ax.xaxis.set_major_formatter(monthFmt) # This is what you needed
ax.xaxis.set_minor_formatter(dayFmt) # This is what you needed
ax.tick_params(direction='out', pad=15)
# format the coords message box
s.plot(figsize=(10,3))
which will look like this:
I am plotting date time on the xaxis (which is actual dates) and then timedelta on the yaxis, which is actually time spans, or amount of time. Originally I was using date time for the yaxis, but I came across the usecase where the time values went over 24 hours, and then it broke the code. So instead I had to use timedelta in order to accommodate these values. But when I try to plot it using plot_date, the yaxis with the timedelta values comes out funny.
I have my information stored in a dataframe originally, and then change the values to a timedelta. This is the code I have to output this graph
import datetime as dt
import matplotlib.dates as mdates
import matplotlib
import numpy as np
import matplotlib.pyplot as plt
import pandas as pd
import matplotlib as mpl
from matplotlib.backends.backend_pdf import PdfPages
plt.close('all')
#put data into dataframe
location='D:\CAT'
csvpath=location+('\metrics_summaryTEST.csv')
print csvpath
df=pd.read_csv(csvpath)
#setup plot/figure
media = set(df.mediaNumber.values)
num_plots = len(media)
ax = plt.gca()
pdfpath=location+('\metrics_graphs.pdf')
pp = PdfPages(pdfpath)
#declaring some variables
publishTimevals=np.zeros(len(df.publishTime.values),dtype="S20")
xdates=np.zeros(len(df.publishTime.values),dtype="S20")
ytimes=np.zeros(len(df.totalProcessTime.values),dtype="S8")
for f in sorted(media):
name = f
plt.figure(f)
plt.clf()
color = next(ax._get_lines.color_cycle)
#PROCESS PUBLISHTIME
publishTimevals= df.loc[df['mediaNumber']==f,['publishTime']]
xdates = map(lambda x: mpl.dates.date2num(dt.datetime.strptime(x, '%Y-%m-%d %H:%M')),publishTimevals.publishTime)
#PROCESS TOTALPROCESSTIME
totalProcessTimevals= df.loc[df['mediaNumber']==f,['totalProcessTime']]
ytimes = pd.to_timedelta(totalProcessTimevals.totalProcessTime)
plt.plot_date(xdates,ytimes,'o-',label='totalProcessTime',color=color)
print ytimes
plt.show()
#format the plot
plt.gcf().autofmt_xdate()
plt.xlabel('publishTime')
plt.ylabel('ProcessTime HH:MM:SS')
plt.legend(loc=8, bbox_to_anchor=(0.5,-0.3),ncol=3,prop={'size':9})
ax.grid('on')
plt.title('%s Processing Time' % (f))
plt.margins(0.05)
#plt.grid('on')
plt.minorticks_on()
plt.grid(which = 'minor', alpha = 0.3)
plt.grid(which = 'major', alpha = 0.7)
plt.show()
Could anyone point out what's going on here?