如何从列中选取值并将它们添加到数学函数中 (Pandas)

Question

I'm ttrying to pick all the values from a dataframe column I have and apply them to a mathematical function. Heres how the data looks:

   Year  %  PM
1  2002  3
2  2002  2.3

I am trying to apply this function :

M = 100000
t = (THE PERCENTAGE FROM THE DATAFRAME)/12
n = 15*12


PM = M*((t*(1+t)**n)/(((1+t)**n)-1))
print(PM)

And my goal is to do it to all the rows and append the value of each result to PM in the dF

Answer 1

You can just add the formula as a column directly to the DF, creating t_div_12 as a vector from the column as below:

M = 100000
n = 15*12
t_div_12 = df["%"]/12
df["PM"] = M*((t_div_12 *(1+t_div_12 )**n)/(((1+t_div_12)**n)-1))

Answer 2

df['PM'] = df['%'].map(lambda t: M*(((t/12)*(1+(t/12))**n)/(((1+(t/12))**n)-1)))

Answer 3

First, I would avoid using constants, which are not repeated in the code. You can apply this function to your dataframe by using this code snippet:

dF = pd.DataFrame([[2002, 3], [2002, 2.3]], columns=["Year", "%"])

dF['PM'] = 100000*((dF["%"]/12*(1+dF["%"]/12)**(15*12))/(((1+dF["%"]/12)**(15*12))-1))

It will give you:

   Year    %            PM
0  2002  3.0  25000.000000
1  2002  2.3  19166.666667