Emplty plot normalised values - python

Want to plot normalised values in array but getting empty plot
import numpy as np
x_array = np.array([2,3,5,6,7,4,8,7,6])
normalized_arr = preprocessing.normalize([x_array])
print(normalized_arr)
plt.plot(normalized_arr)
plt.show()
Empty plot - https://i.stack.imgur.com/NnSbI.png
Is there function that can fill the empty plot with values?

You probably need to change your code into:
import numpy as np
import matplotlib.pyplot as plt
from sklearn import preprocessing
x_array = np.array([2,3,5,6,7,4,8,7,6])
normalized_arr = preprocessing.normalize([x_array])
print(normalized_arr)
plt.plot(x_array.reshape(-1,1),normalized_arr.reshape(-1,1))
plt.show()
Output

Related

size of correlation matrix using matshow

I am trying to format the matrix better. My current code gives me o/p in the format as seen in the image:
import numpy as np
import matplotlib.pyplot as plt
plt.figure(figsize=(10,10))
plt.matshow(final.corr(), fignum = 1)
plt.xticks(range(len(final.columns)), final.columns)
plt.yticks(range(len(final.columns)), final.columns)

Simple Graph Does Not Represent Data

This is a very straightforward question. I have and x axis of years and a y axis of numbers increasing linearly by 100. When plotting this with pandas and matplotlib I am given a graph that does not represent the data whatsoever. I need some help to figure this out because it is such a small amount of code:
The CSV is as follows:
A,B
2012,100
2013,200
2014,300
2015,400
2016,500
2017,600
2018,700
2012,800
2013,900
2014,1000
2015,1100
2016,1200
2017,1300
2018,1400
The Code:
import matplotlib.pyplot as plt
import numpy as np
import pandas as pd
data = pd.read_csv("CSV/DSNY.csv")
data.set_index("A", inplace=True)
data.plot()
plt.show()
The graph this yields is:
It is clearly very inconsistent with the data - any suggestions?
The default behaviour of matplotlib/pandas is to draw a line between successive data points, and not to mark each data point with a symbol.
Fix: change data.plot() to data.plot(style='o'), or df.plot(marker='o', linewidth=0).
Result:
All you need is sort A before plotting.
import matplotlib.pyplot as plt
import numpy as np
import pandas as pd
data = pd.read_csv("CSV/DSNY.csv").reset_index()
data = data.sort_values('A')
data.set_index("A", inplace=True)
data.plot()
plt.show()

Using a colormap for a pandas Series

I have pandas series of complex numbers, which I would like to plot. Currently, I am looping through each point and assigning it a color. I would prefer to generate the plot without the need to loop over each point... Using Series.plot() would be preferable. Converting series to numpy is ok though.
Here is an example of what I currently have:
import pandas as pd
import numpy as np
from matplotlib import pyplot
s = pd.Series((1+np.random.randn(500)*0.05)*np.exp(1j*np.linspace(-np.pi, np.pi, 500)))
cmap = pyplot.cm.viridis
for i, val in enumerate(s):
pyplot.plot(np.real(val), np.imag(val), 'o', ms=10, color=cmap(i/(len(s)-1)))
pyplot.show()
You can use pyplot.scatter, which allows coloring of points based on a value.
pyplot.scatter(np.real(s), np.imag(s), s=50, c=np.arange(len(s)), cmap='viridis')
Here, we set c to an increasing sequence to get the same result as in the question.
You can simply plot the real and imaginary part of the series without a loop.
import pandas as pd
import numpy as np
import matplotlib.pyplot as plt
s = pd.Series((1+np.random.randn(500)*0.05)*np.exp(1j*np.linspace(-np.pi, np.pi, 500)))
plt.plot(s.values.real,s.values.imag, marker="o", ls="")
plt.show()
However, you need to use a scatter plot if you want to have different colors:
import pandas as pd
import numpy as np
import matplotlib.pyplot as plt
s = pd.Series((1+np.random.randn(500)*0.05)*np.exp(1j*np.linspace(-np.pi, np.pi, 500)))
plt.scatter(s.values.real,s.values.imag, c = range(len(s)), cmap=plt.cm.viridis)
plt.show()

plot sensor boolean data matplotlib

I have data from two sensors that I want to visualize. Both sensors take only 0/1 values. How can I change the xaxis labels to show the time series and y axis should have 2 labels 0 and 1 representing the value of sensors along the time series.
import pandas as pd
import matplotlib.pyplot as plt
def drawgraph(inputFile):
df=pd.read_csv(inputFile)
fig=plt.figure()
ax=fig.add_subplot(111)
y = df[['sensor1']]
x=df.index
plt.plot(x,y)
plt.show()
You should have explained what you tried before asking a question for this to be meaningful. Anyway, below is the example.
%matplotlib inline
import pandas as pd
import numpy as np
import matplotlib.pyplot as plt
trange = pd.date_range("11:00", "21:30", freq="30min")
df = pd.DataFrame({'time':trange,'sensor1':np.round(np.random.rand(len(trange))),\
'sensor2':np.round(np.random.rand(len(trange)))})
df = df.set_index('time')
df.plot(yticks=[0,1],ylim=[-0.1,1.1],style={'sensor1':'ro','sensor2':'bx'})

forming histogram plots in python

suppose I want to plot 2 histogram subplots on the same window in python, one below the next. The data from these histograms will be read from a file containing a table with attributes A and B.
In the same window, I need a plot of A vs the number of each A and a plot of B vs the number of each B - directly below the plot of A. so suppose the attributes were height and weight, then we'd have a graph of height and number of people with said height and below it a separate graph of weight and number of people with said weight.
import numpy as np; import pandas as pd
import matplotlib
import matplotlib.pyplot as plt
frame = pd.read_csv('data.data', header=None)
subplot.hist(frame['A'], frame['A.count()'])
subplot.hist(frame['B'], frame['B.count()'])
Thanks for any help!
Using pandas you can make histograms like this:
import numpy as np; import pandas as pd
import matplotlib.pyplot as plt
frame = pd.read_csv('data.csv')
frame.hist(layout = (2,1))
plt.show()
I'm confused by the second part of the question. Do you want four separate subplots?
You can do this:
import numpy as np
import numpy.random
import pandas as pd
import matplotlib.pyplot as plt
#df = pd.read_csv('data.data', header=None)
df = pd.DataFrame({'A': numpy.random.random_integers(0,10,30),
'B': numpy.random.random_integers(0,10,30)})
print df['A']
ax1 = plt.subplot(211)
ax1.set_title('A')
ax1.set_ylabel('number of people')
ax1.set_xlabel('height')
ax2 = plt.subplot(212)
ax2.set_title('B')
ax2.set_ylabel('number of people')
ax2.set_xlabel('weight')
ax1.hist(df['A'])
ax2.hist(df['B'])
plt.tight_layout()
plt.show()

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