Assignment 2

Create two models for the relationship between height and weight based on gender
Modify the code in Assignment 1 to ask for a person's gender as well as their height to produce an estimate of a person's weight using the models you created
Find the weights and use those in your function (i.e. don't generate a model each time)



In [4]:

    
import pandas as pd
import matplotlib.pyplot as plt
plt.style.use('fivethirtyeight')
%matplotlib inline
import statsmodels.formula.api as smf

df = pd.read_csv('heights_weights_genders.csv')



In [5]:

    
df.head(3)



In [12]:

    
female_df = df[df['Gender'] == 'Female']
male_df = df[df['Gender'] == 'Male']

For Female:



In [17]:

    
female_df.describe()









    Out[17]:






  
    
      
      Height
      Weight
    
  
  
    
      count
      5000.000000
      5000.000000
    
    
      mean
      63.708774
      135.860093
    
    
      std
      2.696284
      19.022468
    
    
      min
      54.263133
      64.700127
    
    
      25%
      61.894441
      122.934096
    
    
      50%
      63.730924
      136.117583
    
    
      75%
      65.563565
      148.810926
    
    
      max
      73.389586
      202.237214



In [25]:

    
lm = smf.ols(formula="Weight~Height",data=female_df).fit()
lm.params









    Out[25]:





Intercept   -246.013266
Height         5.994047
dtype: float64



In [26]:

    
female_intercept, female_slope = lm.params



In [36]:

    
female_df.plot(kind="scatter",x="Height",y="Weight")
plt.plot(female_df["Height"],female_slope*female_df["Height"]+female_intercept,"-",color="darkgrey") 

plt.title('Correlation between height and weight for females')
plt.xlabel('Height (inches)')
plt.ylabel('Weight (lbs)')









    Out[36]:





<matplotlib.text.Text at 0x112662048>

For Male:



In [19]:

    
male_df.describe()









    Out[19]:






  
    
      
      Height
      Weight
    
  
  
    
      count
      5000.000000
      5000.000000
    
    
      mean
      69.026346
      187.020621
    
    
      std
      2.863362
      19.781155
    
    
      min
      58.406905
      112.902939
    
    
      25%
      67.174679
      173.887767
    
    
      50%
      69.027709
      187.033546
    
    
      75%
      70.988744
      200.357802
    
    
      max
      78.998742
      269.989699



In [20]:

    
lm = smf.ols(formula="Weight~Height",data=male_df).fit()
lm.params









    Out[20]:





Intercept   -224.498841
Height         5.961774
dtype: float64



In [23]:

    
male_intercept, male_slope = lm.params



In [35]:

    
male_df.plot(kind="scatter",x="Height",y="Weight")
plt.plot(male_df["Height"],male_slope*male_df["Height"]+male_intercept,"-",color="darkgrey") 

plt.title('Correlation between height and weight for males')
plt.xlabel('Height (inches)')
plt.ylabel('Weight (lbs)')









    Out[35]:





<matplotlib.text.Text at 0x1124e1ef0>

Function:



In [89]:

    
gender = input('Male or female? ')

if gender == 'female' or gender == 'Female':
    height = int(input('Height (in inches): '))
    weight = female_slope * height + female_intercept
    print('If a person is female and ' + str(height) + ' inches tall, they probably weigh ' + str(round(weight,2)) + ' pounds.')

elif gender == 'male' or gender == 'Male':
    height = int(input('Height (in inches): '))
    weight = male_slope * height + male_intercept 
    print('If a person is male and ' + str(height) + ' inches tall, they probably weigh ' + str(round(weight,2)) + ' pounds.')
        
else:
    print("Input error.")









    



Male or female? Male
Height (in inches): 57
If a person is male and 57 inches tall, they probably weigh 115.32 pounds.



In [90]:

    
gender = input('Male or female? ')

if gender == 'female' or gender == 'Female':
    height = int(input('Height (in inches): '))
    weight = 5.994047 * height - 246.013266
    print('If a person is female and ' + str(height) + ' inches tall, they probably weigh ' + str(round(weight,2)) + ' pounds.')

elif gender == 'male' or gender == 'Male':
    height = int(input('Height (in inches): '))
    weight = 5.961774 * height - 224.498841
    print('If a person is male and ' + str(height) + ' inches tall, they probably weigh ' + str(round(weight,2)) + ' pounds.')
        
else:
    print("Input error.")









    



Male or female? Male
Height (in inches): 57
If a person is male and 57 inches tall, they probably weigh 115.32 pounds.

	Gender	Height	Weight
0	Male	73.847017	241.893563
1	Male	68.781904	162.310473
2	Male	74.110105	212.740856

	Height	Weight
count	5000.000000	5000.000000
mean	63.708774	135.860093
std	2.696284	19.022468
min	54.263133	64.700127
25%	61.894441	122.934096
50%	63.730924	136.117583
75%	65.563565	148.810926
max	73.389586	202.237214