multiclass_auc

hana_ml.algorithms.pal.metrics.multiclass_auc(data_original, data_predict)

Computes area under curve (AUC) to evaluate the performance of multi-class classification algorithms.

Parameters:
data_originalDataFrame

True class data, structured as follows:

  • Data point ID column.

  • True class of the data point.

data_predictDataFrame

Predicted class data, structured as follows:

  • Data point ID column.

  • Possible class.

  • Classifier-computed probability that the data point belongs to that particular class.

For each data point ID, there should be one row for each possible class.

Returns:
float

The area under the receiver operating characteristic curve.

DataFrame

False positive rate and true positive rate (ROC), structured as follows:

  • ID column, type INTEGER.

  • FPR, type DOUBLE, representing false positive rate.

  • TPR, type DOUBLE, representing true positive rate.

Examples

Input DataFrame df:

>>> df_original.collect()
   ID  ORIGINAL
0   1         1
1   2         1
2   3         1
3   4         2
4   5         2
5   6         2
6   7         3
7   8         3
8   9         3
9  10         3

>>> df_predict.collect()
    ID  PREDICT  PROB
0    1        1  0.90
1    1        2  0.05
2    1        3  0.05
3    2        1  0.80
4    2        2  0.05
5    2        3  0.15
6    3        1  0.80
7    3        2  0.10
8    3        3  0.10
9    4        1  0.10
10   4        2  0.80
11   4        3  0.10
12   5        1  0.20
13   5        2  0.70
14   5        3  0.10
15   6        1  0.05
16   6        2  0.90
17   6        3  0.05
18   7        1  0.10
19   7        2  0.10
20   7        3  0.80
21   8        1  0.00
22   8        2  0.00
23   8        3  1.00
24   9        1  0.20
25   9        2  0.10
26   9        3  0.70
27  10        1  0.20
28  10        2  0.20
29  10        3  0.60

Compute Area Under Curve:

>>> auc, roc = multiclass_auc(data_original=df_original, data_predict=df_predict)

Output:

>>> print(auc)
1.0

>>> roc.collect()
    ID   FPR  TPR
0    0  1.00  1.0
1    1  0.90  1.0
2    2  0.65  1.0
3    3  0.25  1.0
4    4  0.20  1.0
5    5  0.00  1.0
6    6  0.00  0.9
7    7  0.00  0.7
8    8  0.00  0.3
9    9  0.00  0.1
10  10  0.00  0.0