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question about adaboost.
4 messages · Cecilia Lezama, Uwe Ligges
Cecilia Lezama wrote:
Hello, I would like to know how to obtain the misclassification error when performing a boosting analisis with ADABAG package? With:
prop.table(Tesis.boostcv$confusion)
I obtain the confusion matrix, but not the overall missclassification error.
Well, the misclassification error is 1 - diag(table) / sum(table) Uwe Ligges
Thanks in advance, BSc. Cecilia Lezama Facultad de Ciencias - UDELAR Montevideo - Uruguay. [[alternative HTML version deleted]]
______________________________________________ R-help at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Thanks for your quickly answer. I feel embarrassed but I didn't understand
it.
1 - diag(table) / sum(table) Which diagonal? Both of them?
Could you explain it to me with a practical example?
CONFUSION MATRIX
Observed Class
Predicted Class A P
A 138 9
P 1 2
PROBABILITY CONFUSION MATRIX
Observed Class
Predicted Class A P
A 0.920000000 0.060000000
P 0.006666667 0.013333333
Many, many thanks!
----- Original Message -----
From: "Uwe Ligges" <ligges at statistik.tu-dortmund.de>
To: "Cecilia Lezama" <checha at netgate.com.uy>
Cc: <r-help at r-project.org>
Sent: Tuesday, April 28, 2009 9:42 AM
Subject: Re: [R] question about adaboost.
Cecilia Lezama wrote:
Hello, I would like to know how to obtain the misclassification error when performing a boosting analisis with ADABAG package? With:
prop.table(Tesis.boostcv$confusion)
I obtain the confusion matrix, but not the overall missclassification error.
Well, the misclassification error is 1 - diag(table) / sum(table) Uwe Ligges
Thanks in advance, BSc. Cecilia Lezama Facultad de Ciencias - UDELAR Montevideo - Uruguay. [[alternative HTML version deleted]]
______________________________________________ R-help at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Cecilia Lezama wrote:
Thanks for your quickly answer. I feel embarrassed but I didn't understand it. 1 - diag(table) / sum(table) Which diagonal? Both of them? Could you explain it to me with a practical example?
Whoops, this meant to be 1 - sum(diag(table)) / sum(table) i.e. 1 - (138+2)/(138+2+9+1) Uwe Ligges
CONFUSION MATRIX
Observed Class
Predicted Class A P
A 138 9
P 1 2
PROBABILITY CONFUSION MATRIX
Observed Class
Predicted Class A P
A 0.920000000 0.060000000
P 0.006666667 0.013333333
Many, many thanks!
----- Original Message ----- From: "Uwe Ligges"
<ligges at statistik.tu-dortmund.de>
To: "Cecilia Lezama" <checha at netgate.com.uy>
Cc: <r-help at r-project.org>
Sent: Tuesday, April 28, 2009 9:42 AM
Subject: Re: [R] question about adaboost.
Cecilia Lezama wrote:
Hello, I would like to know how to obtain the misclassification error when performing a boosting analisis with ADABAG package? With:
prop.table(Tesis.boostcv$confusion)
I obtain the confusion matrix, but not the overall missclassification error.
Well, the misclassification error is 1 - diag(table) / sum(table) Uwe Ligges
Thanks in advance, BSc. Cecilia Lezama Facultad de Ciencias - UDELAR Montevideo - Uruguay. [[alternative HTML version deleted]]
______________________________________________ R-help at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.