Matplotlib bar chart on datetime index values - python

I'm having trouble getting the following code to display a bar chart properly. The plot has very thin lines which are not visible until you zoom in, but even then it's not clear. I've tried to control with the width option to plt.bar() but it's not doing anything (e.g. tried 0.1, 1, 365).
Any pointers on what I'm doing wrong would be appreciated.
Many thanks
import pandas as pd
import numpy as np
import matplotlib.pylab as plt
import matplotlib.dates as mdates
plt.close('all')
mydateparser2 = lambda x: pd.datetime.strptime(x, "%m/%d/%Y")
colnames2=['Date','Net sales', 'Cost of sales']
df2 = pd.read_csv(r'account-test.csv', parse_dates = ['Date'] , date_parser = mydateparser2, index_col='Date')
df2= df2.filter(items=colnames2)
df2 = df2.sort_values('Date')
print (df2.info())
print (df2)
fig = plt.figure()
plt.bar(df2.index.values, df2['Net sales'], color='red', label='Net sales' )
plt.ylim(500000,2800000)
plt.show()
plt.legend(loc=4)
Resulting output (to show data types)
<class 'pandas.core.frame.DataFrame'>
DatetimeIndex: 15 entries, 2005-12-31 to 2019-12-31
Data columns (total 2 columns):
Net sales 15 non-null int64
Cost of sales 15 non-null int64
dtypes: int64(2)
memory usage: 360.0 bytes
None
Net sales Cost of sales
Date
2005-12-31 1161400 907200
2006-12-31 1193100 928300
2007-12-31 1171100 888100
2008-12-31 1324900 1035700
2009-12-31 1108300 859800
2010-12-31 1173600 891000
2011-12-31 1392400 1050300
2012-12-31 1578200 1171500
2013-12-31 1678200 1224200
2014-12-31 1855500 1346700
2015-12-31 1861200 1328400
2016-12-31 2004300 1439700
2017-12-31 1973300 1421500
2018-12-31 2189100 1608300
2019-12-31 2355700 1715300

Maybe you are trying to plot too many bars on a small plot. Try fig = plt.figure(figsize=(12,6) to have a bigger plot. You can also pass width=0.9 to your bar command:
fig, ax = plt.subplots(figsize=(12,6))
df.plot.bar(y='Net sales', width=0.9, ax=ax) # modify width to your liking
Output:

Related

How to plot a variable dataframe

I have a dataframe with a variable number of stock prices. In other words, I have to be able to plot the entire Dataframe, because I may encounter 1 to 10 stocks prices.
The x axis are dates, the Y axis are Stock prices. Here is a sample of my Df:
df = pd.DataFrame(all_Assets)
df2 = df.transpose()
print(df2)
Close Close Close
Date
2018-12-12 00:00:00-05:00 40.802803 24.440001 104.500526
2018-12-13 00:00:00-05:00 41.249191 25.119333 104.854965
2018-12-14 00:00:00-05:00 39.929325 24.380667 101.578560
2018-12-17 00:00:00-05:00 39.557732 23.228001 98.570381
2018-12-18 00:00:00-05:00 40.071678 22.468666 99.605057
This is not working
fig = go.Figure(data=go.Scatter(df2, mode='lines'),)
I need to plot this entire dataframe on a single chart, with 3 different lines. But the code has to adapt automatically if there is a fourth stock, fifth stock e.g. By the way , I want it to be a Logarithmic plot.
There is a sample in the reference, so let's try to graph it in wide and long format with express and in wide and long format with the graph object. You can choose from these four types to do what you need.
express wide format
df.head()
date GOOG AAPL AMZN FB NFLX MSFT
0 2018-01-01 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000
1 2018-01-08 1.018172 1.011943 1.061881 0.959968 1.053526 1.015988
2 2018-01-15 1.032008 1.019771 1.053240 0.970243 1.049860 1.020524
3 2018-01-22 1.066783 0.980057 1.140676 1.016858 1.307681 1.066561
4 2018-01-29 1.008773 0.917143 1.163374 1.018357 1.273537 1.040708
import plotly.express as px
df = px.data.stocks()
fig = px.line(df, x='date', y=df.columns[1:])
fig.show()
express long format
df_long = df.melt(id_vars='date', value_vars=df.columns[1:],var_name='ticker')
px.line(df_long, x='date', y='value', color='ticker')
graph_objects wide format
import plotly.graph_objects as go
fig = go.Figure()
for ticker in df.columns[1:]:
fig.add_trace(go.Scatter(x=df['date'], y=df[ticker], name=ticker))
fig.show()
graph_objects long format
fig = go.Figure()
for ticker in df_long.ticker.unique():
dff = df_long.query('ticker == #ticker')
fig.add_trace(go.Scatter(x=dff['date'], y=dff['value'], name=ticker))
fig.show()
I recommend you to use pandas.DataFrame.plot. A minimal working example for your case should be just
df2.plot()
. Then just play around with the plot() method and your df2 dataframe to get exactly the output you need.

Pandas/NumPy -- Plotting Dates as X axis

My Goal is just to plot this simple data, as a graph, with x data being dates ( date showing in x-axis) and price as the y-axis. Understanding that the dtype of the NumPy record array for the field date is datetime64[D] which means it is a 64-bit np.datetime64 in 'day' units. While this format is more portable, Matplotlib cannot plot this format natively yet. We can plot this data by changing the dates to DateTime.date instances instead, which can be achieved by converting to an object array: which I did below view the astype('0'). But I am still getting
this error :
view limit minimum -36838.00750000001 is less than 1 and is an invalid Matplotlib date value. This often happens if you pass a non-DateTime value to an axis that has DateTime units
code:
import pandas as pd
import matplotlib.pyplot as plt
df = pd.read_csv(r'avocado.csv')
df2 = df[['Date','AveragePrice','region']]
df2 = (df2.loc[df2['region'] == 'Albany'])
df2['Date'] = pd.to_datetime(df2['Date'])
df2['Date'] = df2.Date.astype('O')
plt.style.use('ggplot')
ax = df2[['Date','AveragePrice']].plot(kind='line', title ="Price Change",figsize=(15,10),legend=True, fontsize=12)
ax.set_xlabel("Period",fontsize=12)
ax.set_ylabel("Price",fontsize=12)
plt.show()
df.head(3)
Unnamed: 0 Date AveragePrice Total Volume 4046 4225 4770 Total Bags Small Bags Large Bags XLarge Bags type year region
0 0 2015-12-27 1.33 64236.62 1036.74 54454.85 48.16 8696.87 8603.62 93.25 0.0 conventional 2015 Albany
1 1 2015-12-20 1.35 54876.98 674.28 44638.81 58.33 9505.56 9408.07 97.49 0.0 conventional 2015 Albany
2 2 2015-12-13 0.93 118220.22 794.70 109149.67 130.50 8145.35 8042.21 103.14 0.0 conventional 2015 Albany
df2 = df[['Date', 'AveragePrice', 'region']]
df2 = (df2.loc[df2['region'] == 'Albany'])
df2['Date'] = pd.to_datetime(df2['Date'])
df2 = df2[['Date', 'AveragePrice']]
df2 = df2.sort_values(['Date'])
df2 = df2.set_index('Date')
print(df2)
ax = df2.plot(kind='line', title="Price Change")
ax.set_xlabel("Period", fontsize=12)
ax.set_ylabel("Price", fontsize=12)
plt.show()
output:

Arrange pandas DataFrame for color Plotting

I have a dataframe which looks like this (left column is the index):
YYYY-MO-DD HH-MI-SS_SSS ATMOSPHERIC PRESSURE (hPa) mean
2016-11-07 14:00:00 1014.028782
2016-11-07 15:00:00 1014.034111
.... ....
2016-11-30 09:00:00 1006.516436
2016-11-30 10:00:00 1006.216156
Now I want to plot a colormap with this data - so I want to create an X (horizontal axis) to be just the dates:
2016-11-07, 2016-11-08,...,2016-11-30
and the Y (Vertical axis) to be the time:
00:00:00, 01:00:00, 02:00:00, ..., 23:00:00
And finally the Z (color map) to be the pressure data for each date and time [f(x,y)].
How can I arrange the data for this kind of plotting ?
Thank you !
With test data prepared like so:
import numpy as np
import pandas as pd
import matplotlib.pyplot as plt
samples = 24 * 365
index = pd.date_range('2017-01-01', freq='1H', periods=samples)
data = pd.DataFrame(np.random.rand(samples), index=index, columns=['data'])
I would do something like this:
data = data.reset_index()
data['date'] = data['index'].apply(lambda x: x.date())
data['time'] = data['index'].apply(lambda x: x.time())
pivoted = data.pivot(index='time', columns='date', values='data')
fig, ax = plt.subplots(1, 1)
ax.imshow(pivoted, origin='lower', cmap='viridis')
plt.show()
Which produces:
To improve the axis labeling, this is a start:
ax.set_yticklabels(['{:%H:%M:%S}'.format(t) for t in data['time'].unique()])
ax.set_xticklabels(['{:%Y-%m-%d}'.format(t) for t in data['date'].unique()])
but you'll need to figure out how to choose how often a label appears with set_xticks() and set_yticks()

Pandas dataframe groupby plot

I have a dataframe which is structured as:
Date ticker adj_close
0 2016-11-21 AAPL 111.730
1 2016-11-22 AAPL 111.800
2 2016-11-23 AAPL 111.230
3 2016-11-25 AAPL 111.790
4 2016-11-28 AAPL 111.570
...
8 2016-11-21 ACN 119.680
9 2016-11-22 ACN 119.480
10 2016-11-23 ACN 119.820
11 2016-11-25 ACN 120.740
...
How can I plot based on the ticker the adj_close versus Date?
Simple plot,
you can use:
df.plot(x='Date',y='adj_close')
Or you can set the index to be Date beforehand, then it's easy to plot the column you want:
df.set_index('Date', inplace=True)
df['adj_close'].plot()
If you want a chart with one series by ticker on it
You need to groupby before:
df.set_index('Date', inplace=True)
df.groupby('ticker')['adj_close'].plot(legend=True)
If you want a chart with individual subplots:
grouped = df.groupby('ticker')
ncols=2
nrows = int(np.ceil(grouped.ngroups/ncols))
fig, axes = plt.subplots(nrows=nrows, ncols=ncols, figsize=(12,4), sharey=True)
for (key, ax) in zip(grouped.groups.keys(), axes.flatten()):
grouped.get_group(key).plot(ax=ax)
ax.legend()
plt.show()
Similar to Julien's answer above, I had success with the following:
fig, ax = plt.subplots(figsize=(10,4))
for key, grp in df.groupby(['ticker']):
ax.plot(grp['Date'], grp['adj_close'], label=key)
ax.legend()
plt.show()
This solution might be more relevant if you want more control in matlab.
Solution inspired by: https://stackoverflow.com/a/52526454/10521959
The question is How can I plot based on the ticker the adj_close versus Date?
This can be accomplished by reshaping the dataframe to a wide format with .pivot or .groupby, or by plotting the existing long form dataframe directly with seaborn.
In the following sample data, the 'Date' column has a datetime64[ns] Dtype.
Convert the Dtype with pandas.to_datetime if needed.
Tested in python 3.10, pandas 1.4.2, matplotlib 3.5.1, seaborn 0.11.2
Imports and Sample Data
import pandas as pd
import pandas_datareader as web # for sample data; this can be installed with conda if using Anaconda, otherwise pip
import seaborn as sns
import matplotlib.pyplot as plt
# sample stock data, where .iloc[:, [5, 6]] selects only the 'Adj Close' and 'tkr' column
tickers = ['aapl', 'acn']
df = pd.concat((web.DataReader(ticker, data_source='yahoo', start='2020-01-01', end='2022-06-21')
.assign(ticker=ticker) for ticker in tickers)).iloc[:, [5, 6]]
# display(df.head())
Date Adj Close ticker
0 2020-01-02 73.785904 aapl
1 2020-01-03 73.068573 aapl
2 2020-01-06 73.650795 aapl
3 2020-01-07 73.304420 aapl
4 2020-01-08 74.483604 aapl
# display(df.tail())
Date Adj Close ticker
1239 2022-06-14 275.119995 acn
1240 2022-06-15 281.190002 acn
1241 2022-06-16 270.899994 acn
1242 2022-06-17 275.380005 acn
1243 2022-06-21 282.730011 acn
pandas.DataFrame.pivot & pandas.DataFrame.plot
pandas plots with matplotlib as the default backend.
Reshaping the dataframe with pandas.DataFrame.pivot converts from long to wide form, and puts the dataframe into the correct format to plot.
.pivot does not aggregate data, so if there is more than 1 observation per index, per ticker, then use .pivot_table
Adding subplots=True will produce a figure with two subplots.
# reshape the long form data into a wide form
dfp = df.pivot(index='Date', columns='ticker', values='Adj Close')
# display(dfp.head())
ticker aapl acn
Date
2020-01-02 73.785904 203.171112
2020-01-03 73.068573 202.832764
2020-01-06 73.650795 201.508224
2020-01-07 73.304420 197.157654
2020-01-08 74.483604 197.544434
# plot
ax = dfp.plot(figsize=(11, 6))
Use seaborn, which accepts long form data, so reshaping the dataframe to a wide form isn't necessary.
seaborn is a high-level api for matplotlib
sns.lineplot: axes-level plot
fig, ax = plt.subplots(figsize=(11, 6))
sns.lineplot(data=df, x='Date', y='Adj Close', hue='ticker', ax=ax)
sns.relplot: figure-level plot
Adding row='ticker', or col='ticker', will generate a figure with two subplots.
g = sns.relplot(kind='line', data=df, x='Date', y='Adj Close', hue='ticker', aspect=1.75)

Is there a way to plot a pandas series in ggplot?

I'm experimenting with pandas and non-matplotlib plotting. Good suggestions are here. This question regards yhat's ggplot and I am running into two issues.
Plotting a series in pandas is easy.
frequ.plot()
I don't see how to do this in the ggplot docs. Instead I end up creating a dataframe:
cheese = DataFrame({'time': frequ.index, 'count' : frequ.values})
ggplot(cheese, aes(x='time', y='count')) + geom_line()
I would expect ggplot -- a project that has "tight integration with pandas" -- to have a way to plot a simple series.
Second issue is I can't get stat_smooth() to display when the x axis is time of day. Seems like it could be related to this post, but I don't have the rep to post there. My code is:
frequ = values.sampler.resample("1Min", how="count")
cheese = DataFrame({'time': frequ.index, 'count' : frequ.values})
ggplot(cheese, aes(x='time', y='count')) + geom_line() + stat_smooth()
Any help regarding non-matplotlib plotting would be appreciated. Thanks!
(I'm using ggplot 0.5.8)
I run into this problem frequently in Python's ggplot when working with multiple stock prices and economic timeseries. The key to remember with ggplot is that data is best organized in long format to avoid any issues. I use a quick two step process as a workaround. First let's grab some stock data:
import pandas.io.data as web
import pandas as pd
import time
from ggplot import *
stocks = [ 'GOOG', 'MSFT', 'LNKD', 'YHOO', 'FB', 'GOOGL','HPQ','AMZN'] # stock list
# get stock price function #
def get_px(stock, start, end):
return web.get_data_yahoo(stock, start, end)['Adj Close']
# dataframe of equity prices
px = pd.DataFrame({n: get_px(n, '1/1/2014', date_today) for n in stocks})
px.head()
AMZN FB GOOG GOOGL HPQ LNKD MSFT YHOO
Date
2014-01-02 397.97 54.71 NaN 557.12 27.40 207.64 36.63 39.59
2014-01-03 396.44 54.56 NaN 553.05 28.07 207.42 36.38 40.12
2014-01-06 393.63 57.20 NaN 559.22 28.02 203.92 35.61 39.93
2014-01-07 398.03 57.92 NaN 570.00 27.91 209.64 35.89 40.92
2014-01-08 401.92 58.23 NaN 571.19 27.19 209.06 35.25 41.02
First understand that ggplot needs the datetime index to be a column in the pandas dataframe in order to plot correctly when switching from wide to long format. I wrote a function to address this particular point. It simply creates a 'Date' column of type=datetime from the pandas series index.
def dateConvert(df):
df['Date'] = df.index
df.reset_index(drop=True)
return df
From there run the function on the df. Use the result as the object in pandas pd.melt using the 'Date' as the id_vars. The returned df is now ready to be plotted using the standard ggplot() format.
px_returns = px.pct_change() # common stock transformation
cumRet = (1+px_returns).cumprod() - 1 # transform daily returns to cumulative
cumRet_dateConverted = dateConvert(cumRet) # run the function here see the result below#
cumRet_dateConverted.info()
<class 'pandas.core.frame.DataFrame'>
DatetimeIndex: 118 entries, 2014-01-02 00:00:00 to 2014-06-20 00:00:00
Data columns (total 9 columns):
AMZN 117 non-null float64
FB 117 non-null float64
GOOG 59 non-null float64
GOOGL 117 non-null float64
HPQ 117 non-null float64
LNKD 117 non-null float64
MSFT 117 non-null float64
YHOO 117 non-null float64
Date 118 non-null datetime64[ns]
dtypes: datetime64[ns](1), float64(8)
data = pd.melt(cumRet_dateConverted, id_vars='Date').dropna() # Here is the method I use to format the data in the long format. Please note the use of 'Date' as the id_vars.
data = data.rename(columns = {'Date':'Date','variable':'Stocks','value':'Returns'}) # common to rename these columns
From here you can now plot your data however you want. A common plot I use is the following:
retPlot_YTD = ggplot(data, aes('Date','Returns',color='Stocks')) \
+ geom_line(size=2.) \
+ geom_hline(yintercept=0, color='black', size=1.7, linetype='-.') \
+ scale_y_continuous(labels='percent') \
+ scale_x_date(labels='%b %d %y',breaks=date_breaks('week') ) \
+ theme_seaborn(style='whitegrid') \
+ ggtitle(('%s Cumulative Daily Return vs Peers_YTD') % key_Stock)
fig = retPlot_YTD.draw()
ax = fig.axes[0]
offbox = ax.artists[0]
offbox.set_bbox_to_anchor((1, 0.5), ax.transAxes)
fig.show()
This is more of a workaround but you can use qplot for quick, shorthand plots using series.
from ggplot import *
qplot(meat.beef)

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