r - How to calculate accuracy from table matrix -
i'm using table
show results kmeans
cluster vs. actual class values.
how can calculate % accuracy based on table. know how manually.
iris-setosa had 50 in cluster 2 while iris-versicolor had 2 in other cluster.
is there way calculate % incorrectly classified instances: 52%
i print confusion matrix classes , clusters. lke this:
0 1 <-- assigned cluster 380 120 | 1 135 133 | 0 cluster 0 <-- 1 cluster 1 <-- 0 incorrectly clustered instances : 255.0 33.2031 %
you can use diag()
select cases on diagonal , use calculate (in)accuracy shown below:
sum(diag(d))/sum(d) #overall accuracy 1-sum(diag(d))/sum(d) #incorrect classification
you can use calculate number of cases (in)correctly classified:
sum(diag(d)) #n cases correctly classified sum(d)-sum(diag(d)) #n cases incorrectly classified
where d
confusion matrix
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