Fitting a cumulative gaussian to data - python

I am trying to fit a cumulative Gaussian distribution to my data, but I get a strange result with negative mu... :
libraries:
import pandas as pd
import matplotlib.pyplot as plt
from scipy.optimize import curve_fit
from scipy.stats import norm
import numpy as np
First I am importing the data from an Excel
data = pd.read_excel ('....xlsx',sheet_name='test', na_filter=True)
the data look like:
then creating a data frame:
data_sort = pd.DataFrame(data, columns=['x','y'])
and fit the pdf:
mu,sigma = curve_fit(norm.cdf, data_sort['x'], data_sort['y'], p0=[0,1])[0]
and I get back mu= -0.512, sigma=0.106, which is just totally wrong...

Related

KMeans Clustering of CSV Data Set

I am trying to create a KMeans clustering model based on a csv data set that I have compiled. The data set is organized as such:
population longitude latitude
Atlanta, GA
Austin, TX
...
I tried just plotting the data, which isn't working, if produces a scatter plot where you can't see the axis or the data points, and I can't really tell of the Kmeans algorithim is working.
import numpy as np
import matplotlib.pyplot as plt
from sklearn.cluster import KMeans
from sklearn import datasets
import pandas as pd
import csv
data = pd.read_csv("data.csv")
print (data.head())
plt.scatter(x=data['Population'].astype(bytes), y=data['Longitude'].astype(bytes), z=data["Latitude"].astype(bytes))
plt.xlim(0,1000000)
plt.ylim(0,5000)
plt.zlim(0,5000)
plt.xlabel('Population')
plt.ylabel('Longitude')
plt.zlabel('Latitude')
plt.title('KMeans Clustering for Population vs. Latitude and Longitude', fontsize = 10)
plt.show()
x = data.iloc[:,1:3] #selecting features
#Clustering
kmeans = KMeans(3)
kmeans.fit(x)
#Clustering Results
indentified_clusters = kmeans.fit_predict(x)
indentified_clusters
array([1,1,0.0,2])
data_with_clusters = data.copy()
data_with_clusters['Clusters'] = identified_clusters
plt.scatter(data_with_clusters['Population'],data_with_clusters['Longitude'],data_with_clusters['Latitude']c=data_with_clusters['Clusters'],cmap='rainbow')
Try the following :
import numpy as np
import pandas as pd
import statsmodels.api as sm
import matplotlib.pyplot as plt
import seaborn as sns
sns.set()
from sklearn.cluster import KMeans
#2 Importing the mall dataset
data= pd.read_csv("xxx")
print(data.head())
plt.scatter(data['Longitude'],data['Latitude'])
plt.xlim(-180,180)
plt.ylim(-90,90)
plt.show()
x = data.iloc[:,1:3] # 1t for rows and second for columns
x
kmeans = KMeans(3)
kmeans.fit(x)
data_with_clusters = data.copy()
data_with_clusters['Clusters'] = indentified_clusters
plt.scatter(data_with_clusters['Longitude'],data_with_clusters['Latitude'],c=data_with_clusters['Clusters'],cmap='rainbow')
plt.show()

Creating scatter plot

Can someone help me with how to create a scatterplot. I have written the following code, however, it is not the scatter plot link that I expected as all data only concentrate 3 values of x-variable
import numpy as np
import pandas as pd
import matplotlib.pyplot as plt
import seaborn as sns
from sklearn.linear_model import LinearRegression
from scipy.stats import skew
from warnings import filterwarnings
filterwarnings('ignore')
df_transactions = pd.read_csv('transactions.csv')
daily_revenue= df_transactions.groupby("days_after_open").sum()['revenue']
df_transactions["daily_revenue"] = daily_revenue
x = df_transactions["days_after_open"]
y = df_transactions["daily_revenue"]
plt.scatter(x,y,alpha=0.2)
plt.xlabel("Days After Open (days)")
plt.ylabel("Daily Reveue ($)")
plt.savefig("plot")
dataframe image
Please define the 'daily_revenue' following before moving to the scatter plot.
y = df_transactions["daily_revenue"]

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()

Unable to get Regression line and the variance bounds in Seaborn pairplot

I am unable to get regression line and the variance bounds around it while plotting seaborn.pairplot with kind=reg as shown in the examples at http://seaborn.pydata.org/generated/seaborn.pairplot.html
import pandas pd
import seaborn as sns
import numpy as np
import matplotlib as plt
# Preparing random dataFrame with two colums, viz., random x and lag-1 values
lst1 = list(np.random.rand(10000))
df = pd.DataFrame({'x1':lst1})
df['x2'] = df['x1'].shift(1)
df = df[df['x2'] > 0]
# Plotting now
pplot = sns.pairplot(df, kind="reg")
pplot.set(ylim=(min(df['x1']), max(df['x1'])))
pplot.set(xlim=(min(df['x1']), max(df['x1'])))
plt.show()
The regression line is there, you just don't see it, because it's hidden by the unnaturally high number of points in the plot.
So let's reduce the number of points and you'll see the regression as expected.
import pandas as pd
import seaborn as sns
import numpy as np
import matplotlib.pyplot as plt
# Preparing random dataFrame with two colums, viz., random x and lag-1 values
lst1 = list(np.random.rand(100))
df = pd.DataFrame({'x1':lst1})
df['x2'] = df['x1'].shift(1)
df = df[df['x2'] > 0]
# Plotting now
pplot = sns.pairplot(df, kind="reg")
plt.show()

Smoothing curve for matplotlib.pyplot using pandas or numpy/scipy

I have a series of data which consists of values from several experiments (1-40, in the MWE it is 1-5). The overall amount of entries in my original data is ~4.000.000, which I try to smooth in order to display it:
import pandas as pd
import numpy as np
import matplotlib.pyplot as plt
from scipy.interpolate import spline
from statsmodels.nonparametric.smoothers_lowess import lowess
df = pd.DataFrame()
df["values"] = np.random.randint(100000, 200000, 1000)
df["id"] = [1,2,3,4,5] * 200
plt.figure(1, figsize=(11.69,8.27))
# Both fail for my amount of data:
plt.plot(spline(df["values"], df["id"], range(100)), "r-")
plt.plot(lowess(df["values"], df["id"]), "r-")
Both, scipy.interplate and statsmodels.nonparametric.smoothers_lowess.lowess, throw out of memory exceptions for my data. Is there any efficient way to solve this like in, e.g., GNU R using ggplot2 and geom_smooth()?
I can't quite tell what you're getting at with all the dimensions to your data, but one very simple thing you can try is to just use the 'markevery' kwarg like so:
import numpy as np
import matplotlib.pyplot as plt
x=np.linspace(1,100,1E7)
y=x**2
plt.figure(1, figsize=(11.69,8.27))
plt.plot(x,y,markevery=100)
plt.show()
This will only plot every nth point (n=100 here).
If that doesn't help then you may want to try just a simple numpy interpolation with fewer samples like so:
x_large=np.linspace(1,100,1E7)
y_large=x**2
x_small=np.linspace(1,100,1E3)
y_small=np.interp(x_small,x_large,y_large)
plt.plot(x_small,y_small)

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