Displaying 20 results from an estimated 10000 matches similar to: "SVM e1071"
2005 Jun 14
1
How to fix false positve rates?
Dear R-users,
I have a set of 12000 image samples. I can divide this set into two
categories: training and testing. I need to classify the test set into
a two qualitative outputs: true or false for some characteristic.
To do the classification I'm using the packages SVM in e1071 library
and LDA in the MASS library. However, I'm with a great number of FALSE
POSITIVE CASES in both
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
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
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
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 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 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,
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,
2011 Jan 13
1
question about svm(e1071)
Dear all,
I executed svm calculation using e1071 library with a microarray data (http://www.iu.a.u-tokyo.ac.jp/~kadota/R/data_Singh_RMA_3274.txt).
Then, I shuffled the data samples and executed svm calculation again.
The results of 2 calculation were different (in SV, coefs and weights).
I attached the script below. Could please tell me why this happens?
If possible please tell me how to make
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
2010 May 14
4
Categorical Predictors for SVM (e1071)
Dear all,
I have a question about using categorical predictors for SVM, using "svm"
from library(e1071). If I have multiple categorical predictors, should they
just be included as factors? Take a simple artificial data example:
x1<-rnorm(500)
x2<-rnorm(500)
#Categorical Predictor 1, with 5 levels
x3<-as.factor(rep(c(1,2,3,4,5),c(50,150,130,70,100)))
#Catgegorical Predictor
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
2011 Sep 24
0
Assessing prediction performance of SVM using e1071 package
Dear R-Users!
I am using the svm function (e1071 package) to classify two groups using a
set of 180 indicator variables. Now I am confused about the cross-validation
procedure.
(A) On one hand I use the setting cross=10 in the svm function to run 10
cross-validation iterations and to get an estimate of the svm's performance
in prediction.
(B) On the other hand most tutorials I found
2010 Jul 14
1
question about SVM in e1071
Hi,
I have a question about the parameter C (cost) in svm function in e1071. I
thought larger C is prone to overfitting than smaller C, and hence leads to
more support vectors. However, using the Wisconsin breast cancer example on
the link:
http://planatscher.net/svmtut/svmtut.html
I found that the largest cost have fewest support vectors, which is contrary
to what I think. please see the scripts
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
2010 Nov 23
5
cross validation using e1071:SVM
Hi everyone
I am trying to do cross validation (10 fold CV) by using e1071:svm method. I
know that there is an option (?cross?) for cross validation but still I
wanted to make a function to Generate cross-validation indices using pls:
cvsegments method.
#####################################################################
Code (at the end) Is working fine but sometime caret:confusionMatrix