I have the following Dataset and I wanna create a plot, which to columns compares with each other.
import pandas as pd
import matplotlib.pyplot as plt
import numpy as np
ds=pd.read_csv('h-t-t-p-:bit.ly/uforeports') #My DataSet
ds.head(5) # Only the fist 5 rows to show
ds1= ds.head(4).drop(['Colors Reported','State'],axis=1) # Droping of unnecesssary rows
print(ds1)
Now I wanna compare "City" and "Shape Reported" with help of plotting. I found something with Pandas but this is not so elegant!
x=ds.loc[0:100,['State']]
y=ds.loc[0:100,['Shape Reported']]
x.apply(pd.value_counts).plot(kind='bar', subplots=True)
y.apply(pd.value_counts).plot(kind='bar', subplots=True)
Do you know a better solution with Matplotlib to this problem?
This is what I want
It's not exactly clear how you want to compare them.
The simplest way of drawing a bar chart is:
df['State'].value_counts().plot.bar()
df['Shape Reported'].value_counts().plot.bar()
If you just want to do it for the first 100 rows as in your example, just add head(100):
df['State'].head(100).value_counts().plot.bar()
df['Shape Reported'].head(100).value_counts().plot.bar()
EDIT:
To compare the two values you can plot a bivariate distribution plot. This is easily done with seaborn:
import seaborn
sns.displot(df,x='State', y='Shape Reported', height=6, aspect=1.33)
Result:
Related
I am new to programming, and I'm having difficulty plotting multiple graphs. What I am trying to get is a graph containing values of K along the Y-axis plotted against values of Dk. I need this graph to contain all the K=f(Dk) for each temperature Tcwin in range (10,40,1)
While the code seems to be working well and I have obtained the data I was trying to calculate, I can't seem to plot them. Any help would be appreciated.
import numpy as np
import pandas as pd
A=3000
d_in=20
CF=0.85
w=2.26
Tcwin=12
Dk=np.arange(27.418,301.598,27.418)
dk=(Dk*1000/(A*3.600))
cp=4.19
Gw=13000
e=2.718281828
f_velocity=w*1.1/(20**0.25)
for Tcwin in range(10,40,1):
while Tcwin<35:
print(Tcwin)
f_w=0.12*CF*(1+0.15*Tcwin)
Ф_в=f_velocity**f_w
K=CF*4070*((1.1*w/(d_in**0.25))**(0.12*CF*(1+0.15*Tcwin)))*(1-(((35-Tcwin)**2)*(0.52-0.0072*dk)*(CF**0.5))/1000)
n=(K*A)/(cp*Gw*1000)
Tcwout_theor=Tcwin+(Dk*2225/(cp*Gw))
Subcooling_theor=(Tcwout_theor-Tcwin)/(e**(K*A/(cp*(Gw*1000/3600)*1000)))
TR_theor=Tcwout_theor-Tcwin
Tsat_theor=Tcwout_theor+Subcooling_theor
print(K)
print(Tcwout_theor)
print(Subcooling_theor)
print(Tsat_theor)
Tcwin+=1
else:
print('Loop done')
Is this what you are looking for? plotting after each run:
import numpy as np
import pandas as pd
A=3000
d_in=20
CF=0.85
w=2.26
Tcwin=12
Dk=np.arange(27.418,301.598,27.418)
dk=(Dk*1000/(A*3.600))
cp=4.19
Gw=13000
e=2.718281828
f_velocity=w*1.1/(20**0.25)
for Tcwin in range(10,40,1):
while Tcwin<35:
print(Tcwin)
f_w=0.12*CF*(1+0.15*Tcwin)
Ф_в=f_velocity**f_w
K=CF*4070*((1.1*w/(d_in**0.25))**(0.12*CF*(1+0.15*Tcwin)))*(1-(((35-Tcwin)**2)*(0.52-0.0072*dk)*(CF**0.5))/1000)
n=(K*A)/(cp*Gw*1000)
Tcwout_theor=Tcwin+(Dk*2225/(cp*Gw))
Subcooling_theor=(Tcwout_theor-Tcwin)/(e**(K*A/(cp*(Gw*1000/3600)*1000)))
TR_theor=Tcwout_theor-Tcwin
Tsat_theor=Tcwout_theor+Subcooling_theor
print(K)
print(Tcwout_theor)
print(Subcooling_theor)
print(Tsat_theor)
Tcwin+=1
plt.plot(K,dk) #---------------> this is the code for plotting
else:
print('Loop done')
The plot below shows the correlation for one column. The problem is that the numbers are not readable, because there are many columns in it.
How is it possible to show only 5 or 6 most important columns and not all of them with very low importance?
plt.figure(figsize=(20,3))
sns.heatmap(df.corr()[['price']].sort_values('price', ascending=False).iloc[1:].T, annot=True,
cmap='Spectral_r', vmax=0.9, vmin=-0.31)
You can limit the cells shown via .iloc[1:7]. If you also want to show the highest negative values, you could create a second plot with .iloc[-6:]. To have both together, you could use numpy's slicing function and write .iloc[np.r_[1:4, -3:0]].
import numpy as np
import pandas as pd
import matplotlib.pyplot as plt
import seaborn as sns
df = pd.DataFrame(np.random.rand(7, 27), columns=['price'] + [*'abcdefghijklmnopqrstuvwxyz'])
plt.figure(figsize=(20, 3))
sns.heatmap(df.corr()[['price']].sort_values('price', ascending=False).iloc[1:7].T,
annot=True, annot_kws={'rotation':90, 'size': 20},
cmap='Spectral_r', vmax=0.9, vmin=-0.31)
plt.show()
annot can also be a list of labels. Using this, you can define a string matrix that you use to display the desired numbers and set the others to an empty string.
import matplotlib.pyplot as plt
import numpy as np; np.random.seed(0)
import seaborn as sns; sns.set_theme()
import pandas as pd
from string import ascii_letters
# generate random data
rs = np.random.RandomState(33)
df = pd.DataFrame(data=rs.normal(size=(100, 26)),
columns=list(ascii_letters[26:]))
importance_index = 5 # until which idx to hide values
data = df.corr()[['A']].sort_values('A', ascending=False).iloc[1:].T
labels = data.astype(str) # make a str-copy
labels.iloc[0,:importance_index] = ' ' # mask columns that you want to hide
sns.heatmap(data, annot=labels, cmap='Spectral_r', vmax=0.9, vmin=-0.31, fmt='', annot_kws={'rotation':90})
plt.show()
The output on some random data:
This works but it has its limits, particulary with setting fmt='' (can't use it to conveniently format decimals anymore, need to do it manually now). I would also question whether your approach is even the best one to take here. I think consistency in plots is quite important. I would rather evaluate if we can't rotate the heatmap labels (I've included it above) or leave them out completely since it is technically redundant due to the color-coding. Alternatively, you could only plot the cells with the "important" values.
The following code when graphed looks really messy at the moment. The reason is I have too many values for 'fare'. 'Fare' ranges from [0-500] with most of the values within the first 100.
import pandas as pd
import numpy as np
import seaborn as sns
import matplotlib.pyplot as plt
titanic = sns.load_dataset("titanic")
y =titanic.groupby([titanic.fare//1,'sex']).survived.mean().reset_index()
sns.set(style="whitegrid")
g = sns.factorplot(x='fare', y= 'survived', col = 'sex', kind ='bar' ,data= y,
size=4, aspect =2.5 , palette="muted")
g.despine(left=True)
g.set_ylabels("Survival Probability")
g.set_xlabels('Fare')
plt.show()
I would like to try slicing up the 'fare' of the plots into subsets but would like to see all the graphs at the same time on one screen. I was wondering it this is possible without having to resort to groupby.
I will have to play around with the values of 'fare' to see what I would want each graph to represent, but for a sample let's use break up the graph into these 'fare' values.
[0-18]
[18-35]
[35-70]
[70-300]
[300-500]
So the total would be 10 graphs on one page, because of the juxtaposition with the opposite sex.
Is it possible with Seaborn? Do I need to do a lot of configuring with matplotlib? Thanks.
Actually I wrote a little blog post about this a while ago. If you are plotting histograms you can use the by keyword:
import matplotlib.pyplot as plt
import seaborn.apionly as sns
sns.set() #rescue matplotlib's styles from the early '90s
data = sns.load_dataset('titanic')
data.hist(by='class', column = 'fare')
plt.show()
Otherwise if you're just plotting value-counts, you have to roll your own grid:
def categorical_hist(self,column,by,layout=None,legend=None,**params):
from math import sqrt, ceil
if layout==None:
s = ceil(sqrt(self[column].unique().size))
layout = (s,s)
return self.groupby(by)[column]\
.value_counts()\
.sort_index()\
.unstack()\
.plot.bar(subplots=True,layout=layout,legend=None,**params)
categorical_hist(data, by='class', column='embark_town')
Edit If you want survival rate by fare range, you could do something like this
data.groupby(pd.cut(data.fare,10)).apply(lambda x.survived.sum(): x./len(x))
I have a dataset that I want to plot with FacetGrids using the seaborn library. The problem is my data is "sparse"; some of the individual subplots don't exist (ie. there are zero data points). I would like those cells to either not show up, or just show up and be blank, but still see the subplots that have data. Here's a simple example:
import pandas as pd
import seaborn as sns
import matplotlib.pyplot as plt
df = pd.DataFrame(columns=['a','b','c','d'],
data=[[1,1,1,4],[1,2,2,8],[2,1,2,12],[2,1,3,14]])
print df
g = sns.FacetGrid(df, col='a', row='b', hue='c')
g.map(plt.scatter, 'c', 'd', marker='o')
Unfortunately, when I plot this, I just get four empty plots instead of 3 filled plots and one empty one. If I change the last row of data to [2,2,3,14] instead, then all four plots appear as expected. Is this a bug in seaborn? Can I work around it somehow?
I wish to plot a pandas time-series object data with matplotlib. For a simple line chart data.plot(), I was able to successfully change the x-axis date format with ax.xaxis.set_major_formatter(md.DateFormatter('%Y-%m-%d %H:%M:%S')).
However, I am not able to do the same for a bar chart data.plot(kind='bar'). And the chart wouldn't appear. Is there a way to change data format for pandas bar chart? I know I can create a chart with plt.bar method, but I need to use pandas stacked bar chart for more complicated data.
import matplotlib.pyplot as plt
import matplotlib.dates as md
import numpy as np
import pandas as pd
import datetime as dt
import time
n=20
duration=1000
now=time.mktime(time.localtime())
timestamps=np.linspace(now,now+duration,n)
dates=[dt.datetime.fromtimestamp(ts) for ts in timestamps]
values=np.sin((timestamps-now)/duration*2*np.pi)
data=pd.Series(values, index=dates)
fig=figure(figsize(5,5))
ax=fig.add_subplot(111)
data.plot(kind='bar')
ax.xaxis.set_major_formatter(md.DateFormatter('%Y-%m-%d %H:%M:%S'))
Since Pandas simply uses matplotlib you can of course create an identical (stacked) barchart with matplotlib. There is not reason why you can only use Pandas for that.
Its not going to help in this case though. Matplotlib's bar() changes the xvalues from dates to floats, therefore a DateFormatter doesnt work anymore. You can check the xticks with ax.get_xticks().
I dont see how you can make the xticks dates, but you can override the xticklabels yourself:
ax.set_xticklabels([dt.strftime('%Y-%m-%d %H:%M:%S') for dt in data.index.to_pydatetime()])
If you have grouped your data using groupby then you can do the same thing as the answer above using:
new_ticks = []
for dt in data.index:
new_ticks.append(datetime.datetime(dt[0],dt[1],1))
ax.set_xticklabels([dt.strftime('%Y-%m') for dt in new_ticks])
Mine was summed and grouped by month so the index tuple was only (2009,4) for example. Obviously, if you have more aspects to your tuple (i.e. day, hour) then you would add those to the datetime function