Analysis of Top1 accuracy and top5 accuracy examples

top1-Accuracy,top5-Accuracy Example analysis

Symbol definition ：

• TP(True Positive): The number of positive samples labeled and classified

• FN(False Negative): The number of samples with positive labels and negative labels

• FP(False Positive): The number of samples with negative labels and positive labels

• TN(True Negative): The number of negative samples labeled and classified

• $Accuracy=\frac{TP+FN}{TP+FN+FP+TN}$

• $Top-1Accuracy=\frac{{\sum }_{i=0}^{N-1}(f(x_i)==y_i)}{N}$, among $x_i$ The categories of are $y_i$, The category is N,$f$ For the prediction category function .
  Practical significance ： For a picture , After the network prediction category , If the maximum probability value contains the correct answer , That is to say, it is believed that .

• $Top-5Accuracy$
  Supplementary examples ：
  Let a dataset have 10 Categories ： Dog 、 cat 、 chicken 、 cattle 、 fish 、 rabbit 、 rat 、 Horse 、 bird 、 Dragonfly .
  Use the trained model to predict what kind of animals in a picture belong to , There is a picture of a dog , If predicted ： Dog (98%)、 cat (90%)、 chicken (80%)、 cattle (60%)、 fish (40%)、 rabbit (30%)、 rat (25%)、 Horse (20%)、 bird (10%)、 Dragonfly (5%).
  For this picture $top1-Accuracy$ by 100%, The category with the highest probability is correct if it is the same as the actual category , The most likely one is the dog , by 98%.
  For this picture $top5-Accuracy$ by 100%, Before the highest probability 5 If one of the categories is the same as the actual category . Include dogs in the top five probability (98%)、 cat (90%)、 chicken (80%)、 cattle (60%)、 fish (40%), Among them are dogs .
  conversely , If predicted ： cat (98%)、 cattle (90%)、 Dog (80%)、 chicken (60%)、 fish (40%)、 rabbit (30%)、 rat (25%)、 Horse (20%)、 bird (10%)、 Dragonfly (5%).
  For this picture $top1-Accuracy$ by 0%, The most likely one is the cat , Not a dog .
  For this picture $top5-Accuracy$ by 100%, Before the highest probability 5 If one of the categories is the same as the actual category . Include cats in the top five probability (98%)、 cattle (90%)、 Dog (80%)、 chicken (60%)、 fish (40%), There are dogs .