[R] Regarding SVM using R
Abbas R. Ali
abbas4s at yahoo.com
Tue Sep 8 15:09:25 CEST 2009
Hi Steve
I am facing a little problem in predict function which is I think mismatch of dimension. Infacted area is covered by ***.
svm = function()
{
library(RODBC) # load RODBC library for database access
channel = odbcConnect("demo_dsn", "sa", "1234") # connecting to the database with the dabtabase
data = sqlQuery(channel, "SELECT top 100 * FROM [Demographics].[dbo].[CHA_Training]")
odbcClose(channel) # close the database connection
index = 1:nrow(data) # getting a vector of same size as data
sample_index <- sample(index, length(index) / 3) # samples of the above vector
training <- data[-sample_index, ] # 2/3 training data
validation <- data[sample_index, ] # 1/3 test data
x = training[, length(training)]
# seperating class labels
model.ksvm = ksvm(x, data = training, kernel = "rbfdot", kpar= list(sigma = 0.05), C = 5, cross = 3) # train data through SVM
*******************************************************************
Problamisitc area:
prSV = predict(model.ksvm, validation[, -length(validation)], type = "decision") # validate data
Error: Error in .local(object, ...) : test vector does not match model !
Notes: If I modified the predict function as "prSV = predict(model.ksvm, validation[, length(validation)], type = "decision")"
then it works but its not correct.
*****************************************************************
table(prSV, validation[, length(validation)]) # draw table
}
Thanks
Abbas
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