python - 使用另一个数据帧中的系数将方程应用于数据帧

Question

我必须有 2 个数据框:

input_df

Apples    Pears   Peaches   Grapes
12        23       0         4
10        0        0         4
12        16       12        5
6         0        0         11

coefficients_df

Fruit       n    w1      w2
Apples      2    0.4     40
Pears       1    0.1     43
Peaches     1    0.6     51
Grapes      2    0.5     11

我正在尝试将方程 y = w2*(1-exp(-w1*input_df^n)) 应用于 input_df。该方程从 coefficients_df

中获取系数

这是我尝试过的:

# First map coefficients_df to input_df
merged_df = input_df.merge(coefficients_df.pivot('Fruit'), on=['Apples','Pears','Peaches','Grapes'])

# Apply function to each row
output_df = merged_df.apply(lambda x: w2*(1-exp(-w1*x^n))

Answer 1

使用简单的索引对齐:

coeff = coefficients_df.set_index('Fruit')

y = coeff['w2']*(1-np.exp(-coeff['w1']*input_df**coeff['n']))

输出:

      Apples     Pears    Peaches     Grapes
0  40.000000  38.68887   0.000000  10.996310
1  40.000000   0.00000   0.000000  10.996310
2  40.000000  34.31845  50.961924  10.999959
3  39.999978   0.00000   0.000000  11.000000