Displaying 20 results from an estimated 10000 matches similar to: "Assessing prediction performance of SVM using e1071 package"
2011 Sep 27
0
Workflow for binary classification problem using svm via e1071 package
Dear R-list!
I am using the e1071 package in R to solve a binary classification problem
in a dataset of round 180 predictor variables (blood metabolites) of two
groups of subjects (patients and healthy controls). I am confused regarding
the correct way to assess the classification accuracy of the trained svm.
(A) The svm command allows to specificy via the 'cross=k' parameter to
specify a
2006 Feb 02
0
crossvalidation in svm regression in e1071 gives incorre ct results (PR#8554)
1. This is _not_ a bug in R itself. Please don't use R's bug reporting
system for contributed packages.
2. This is _not_ a bug in svm() in `e1071'. I believe you forgot to take
sqrt.
3. You really should use the `tot.MSE' component rather than the mean of
the `MSE' component, but this is only a very small difference.
So, instead of spread[i] <- mean(mysvm$MSE), you
2007 Oct 27
1
problems in cross validation of SVM in pakage "e1071"
Hi:
I am a newer in using R for data mining, and find the "e1071" pakage an excellent tool in doing data mining work!
what frustrated me recently is that when I using the function "svm" and using the "cross=10" parameters, I got all the "accuracies" of the model greater than 1. Isn't that the accuracy should be smaller than 1? so I wander how, the
2006 Feb 02
0
crossvalidation in svm regression in e1071 gives incorrect results (PR#8554)
Full_Name: Noel O'Boyle
Version: 2.1.0
OS: Debian GNU/Linux Sarge
Submission from: (NULL) (131.111.8.96)
(1) Description of error
The 10-fold CV option for the svm function in e1071 appears to give incorrect
results for the rmse.
The example code in (3) uses the example regression data in the svm
documentation. The rmse for internal prediction is 0.24. It is expected the
10-fold CV rmse
2009 May 11
1
Problems to run SVM regression with e1071
Hi R users,
I'm trying to run a SVM - regression using e1071 package but the function svm() all the time apply a classification method rather than a regression.
svm.m1 <- svm(st ~ ., data = train, cost = 1000, gamma = 1e-03)
Parameters:
SVM-Type: C-classification
SVM-Kernel: radial
cost: 1000
gamma: 0.001
Number of Support Vectors: 209
2006 Jan 18
2
Help with plot.svm from e1071
Hi.
I'm trying to plot a pair of intertwined spirals and an svm that
separates them. I'm having some trouble. Here's what I tried.
> library(mlbench)
> library(e1071)
Loading required package: class
> raw <- mlbench.spirals(200,2)
> spiral <- data.frame(class=as.factor(raw$classes), x=raw$x[,1], y=raw$x[,2])
> m <- svm(class~., data=spiral)
> plot(m,
2010 May 05
2
probabilities in svm output in e1071 package
svm.fit<-svm(as.factor(out) ~ ., data=all_h, method="C-classification",
kernel="radial", cost=bestc, gamma=bestg, cross=10) # model fitting
svm.pred<-predict(svm.fit, hh, decision.values = TRUE, probability = TRUE) #
find the probability, but can not find.
attr(svm.pred, "probabilities")
> attr(svm.pred, "probabilities")
1 0
1 0 0
2 0
2001 Nov 20
2
segfault using svm from e1071 (PR#1178)
This could be a bug in the e1071 svm code, but maybe not -- I guess I'll
send it here anyway. It's reproducible.
> x <- seq (0.1,5,by=0.05)
> y <- log(x) + rnorm (x, sd=0.2)
> library(e1071)
> m <- svm (x,y)
Process R segmentation fault at Tue Nov 20 23:34:19 2001
> version
_
platform i686-pc-linux-gnu
arch i686
os
2004 Dec 16
2
reading svm function in e1071
Hi,
If I try to read the codes of functions in e1071 package, it gives me following error message.
>library(e1071)
> svm
function (x, ...)
UseMethod("svm")
<environment: namespace:e1071>
> predict.svm
Error: Object "predict.svm" not found
>
Can someone help me on this how to read the codes of the functions in the e1071 package?
Thanks.
Raj
2017 Sep 02
0
problem in testing data with e1071 package (SVM Multiclass)
Hello all,
this is the first time I'm using R and e1071 package and SVM multiclass
(and I'm not a statistician)! I'm very confused, then. The goal is: I
have a sentence with sunny; it will be classified as "yes" sentence; I
have a sentence with cloud, it will be classified as "maybe"; I have a
sentence with rainy il will be classified as "no".
The
2010 Jul 09
1
interpretation of svm models with the e1071 package
Dear all,
after having calibrated a svm model through the svm() command of the
e1071 package, is there a way to
i) represent the modeled relationships between the y and X variables
(response variable vs. predictors)?
ii) rank the influence of the predictors used in the model?
Right now I am more interested in regression models, but I guess this
would be useful for classification too.
Thank
2004 Dec 18
1
erro in SVM (packsge "e1071")
Hello,
I am using SVM under e1071 package for nu-regression with 18 parameters. The
variables are ordered factors, factors, date or numeric datatypes. I use the
linear kernel.
It gives the following error that I cannot solve. I tryed debug, browser and
all that stuff, but no way.
The error is:
Error in get(ctr, mode = "function", envir = parent.frame())(levels(x), :
2011 Feb 23
0
svm(e1071) and scaling of weights
I expected, that I will get the same prediction, if I multiply the
weights for all classes with a constant factor, but I got different
results. Please look for the following code.
> library(e1071)
> data(Glass, package = "mlbench")
> index <- 1:nrow(Glass)
> testindex <- sample(index, trunc(length(index)/5))
> testset <- Glass[testindex, ]
> trainset <-
2009 Mar 12
0
e1071 SVM one-classification tune problem
Hello all,
I am using the e1071 SVM with the tune options for classification, which work pretty well, given the examples of using tune.svm function for classification. But I have not found any example to tune the SVM novelty detection (one-classification) parameters (gamma, cost, nu), for example this are some of the options I have tried with no success:
obj<-tune(svm, x,y, type
2012 Dec 02
1
e1071 SVM: Cross-validation error confusion matrix
Hi,
I ran two svm models in R e1071 package: the first without cross-validation
and the second with 10-fold cross-validation.
I used the following syntax:
#Model 1: Without cross-validation:
> svm.model <- svm(Response ~ ., data=data.df, type="C-classification",
> kernel="linear", cost=1)
> predict <- fitted(svm.model)
> cm <- table(predict,
2012 Mar 02
1
e1071 SVM: Cross-validation error confusion matrix
Hi,
I ran two svm models in R e1071 package: the first without cross-validation
and the second with 10-fold cross-validation.
I used the following syntax:
#Model 1: Without cross-validation:
> svm.model <- svm(Response ~ ., data=data.df, type="C-classification",
> kernel="linear", cost=1)
> predict <- fitted(svm.model)
> cm <- table(predict,
2013 Jan 15
0
e1071 SVM, cross-validation and overfitting
I am accustomed to the LIBSVM package, which provides cross-validation
on training with the -v option
% svm-train -v 5 ...
This does 5 fold cross validation while building the model and avoids
over-fitting.
But I don't see how to accomplish that in the e1071 package. (I
learned that svm(... cross=5 ...) only _tests_ using cross-validation
-- it doesn't affect the training.) Can
2009 Feb 20
0
e1071 package for SVM
Dear all,
I got a code for e1071 package in R for SVM regression. I
have used *m$coefs* for extracting the coefficients but I am getting only
72 . How can I extract coefficients of the predictors set? Does it mean
that I will get only 72 as *Number of Support Vectors: 72. *
**
Thanks in advance
Code:
--------------
library(e1071)
> # create data
> x <- seq(0.1, 5,
2007 Mar 15
0
[e1071] predict.svm bug ?
Hi all,
I'm using SVM to classify data (2 classes) and I get strange results :
> model = svm(x, y, probability = TRUE)
> pred = predict(model, x, decision.values = TRUE, probability = FALSE)
> table(pred,y)
y
pred ctl nuc
ctl 82 3
nuc 5 84
> pred
1 2 3 4 5 6 7 8 ....
nuc nuc nuc nuc nuc nuc nuc ctl ....
And now, with probabities computation :
2009 Aug 04
1
Save model and predictions from svm
Hello,
I'm using the e1071 package for training an SVM. It seems to be working
well.
This question has two parts:
1) Once I've trained an SVM model, I want to USE it within R at a later
date to predict various new data. I see the write.svm command, but
don't know how to LOAD the model back in so that I can use it tomorrow.
How can I do this?
2) I would like to add the