Displaying 20 results from an estimated 4000 matches similar to: "help with nnet"
2010 Oct 12
1
need help with nnet
HI, Dear R community,
My data set has 2409 variables, the last one is response variable. I have
used the nnet after feature selection and works. But this time, I am using
nnet to fit a model without feature selection. I got the following error
information:
> dim(train)
[1] 1827 2409
nnet.fit<-nnet(as.factor(out) ~ ., data=train, size=3, rang=0.3,
decay=5e-4, maxit=500) # model
2010 Jun 24
1
help in SVM
HI, GUYS,
I used the following codes to run SVM and get prediction on new data set hh.
dim(all_h)
[1] 2034 24
dim(hh) # it contains all the variables besides the variables in all_h
data set.
[1] 640 415
require(e1071)
svm.tune<-tune(svm, as.factor(out) ~ ., data=all_h,
ranges=list(gamma=2^(-5:5), cost=2^(-5:5)))# find the best parameters.
bestg<-svm.tune$best.parameters[[1]]
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
2010 Sep 07
1
change the for loops with lapply
cv.fold<-function(i, size=3, rang=0.3){
cat('Fold ', i, '\n')
out.fold.c <-((i-1)*c.each.part +1):(i*c.each.part)
out.fold.n <-((i-1)*n.each.part +1):(i*n.each.part)
train.cv <- n.cc[-out.fold.c, c(2:2401, 2417)]
train.nv <- n.nn[-out.fold.n, c(2:2401, 2417)]
train.v<-rbind(train.cv, train.nv) #training data for feature
2003 Oct 15
1
nnet: Too many weights?
I am using library(nnet) to train up an ANN with what I believe is a
moderately sized dataset, but R is complaining about too many weights:
---
> nn.1 <- nnet(t(data), targets, size = 4, rang = 0.1, decay = 5e-4, maxit =
200)
Error in nnet.default(t(data), targets, size = 4, rang = 0.1, decay = 5e-04,
:
Too many (1614) weights
> dim(targets)
[1] 146 2
> dim(data) ## Note
2004 Mar 30
1
classification with nnet: handling unequal class sizes
I hope this question is adequate for this list
I use the nnet code from V&R p. 348: The very nice and general function
CVnn2() to choose the number of hidden units and the amount of weight
decay by an inner cross-validation- with a slight modification to use it
for classification (see below).
My data has 2 classes with unequal size: 45 observations for classI and
116 obs. for classII
With
2004 Jun 14
2
CVnn2 + nnet question
Hi,
I am trying to determine the number of units in the hidden layer
and the decay rate using the CVnn2 script found in MASS directory
(reference: pg 348,MASS-4).
The model that I am using is in the form of Y ~ X1 + X2 + X3...
+ X11 and the underlying data is time-series in nature.
I found the MASS and nnet package extremely useful (many thanks
to the contributors).
However I am getting
2007 Dec 14
2
train nnet
Hi R-helpers,
Can some one tell me how to train 'mynn' of this type?:
mynn <- nnet(y ~ x1 + ..+ x8, data = lgist, size = 2, rang = 0.1,
decay = 5e-4, maxit = 200)
I assume that this nn is untrained, and to train I have to split the
original data into train:test data set,
do leave-one-out refitting to refine the weights (please straighten
this up if I was wrong).
I just don't know
2009 Nov 02
1
modifying predict.nnet() to function with errorest()
Greetings,
I am having trouble calculating artificial neural network
misclassification errors using errorest() from the ipred package.
I have had no problems estimating the values with randomForest()
or svm(), but can't seem to get it to work with nnet(). I believe
this is due to the output of the predict.nnet() function within
cv.factor(). Below is a quick example of the problem I'm
2005 Jul 27
1
how to get actual value from predict in nnet?
Dear All,
After followed the help of nnet, I could get the networks trained and, excitedly, get the prediction for other samples. It is a two classes data set, I used "N" and "P" to label the two. My question is, how do I get the predicted numerical value for each sample? Not just give me the label(either "N" or "P")? Thanks!
FYI: The nnet example I
2009 May 29
1
final value of nnet with censored=TRUE for survival analysis
Hi there,
I´ve a question concerning the nnet package in the area of survival analysis: what is the final value, which is computed to fit the model with the following nnet-c
all:
net <- nnet(cat~x,
data=d,
size=2,
decay=0.1,
censored=TRUE,
maxit=20,
Wts=rep(0,22),
Hess=TRUE)
where cat is a matrix with a row for each record and
2011 Jun 01
1
nnet inappropriate fit for class error
Hi,
I am trying to run a nnet algorithm but when I try to use the predict function with type='class', it gives the following error:
fit <- nnet(y~., size = 1, data = train.set, rang = 0.5, maxit=200, decay = 0)
predict<-predict(fit,test.set,type='class')
Error in predict.nnet(fit, test.set, type = "class") :
inappropriate fit for class
I couldn't figure
2007 Jul 15
1
NNET re-building the model
Hello,
I've been working with "nnet" and now I'd like to use the weigths, from
the fitted model, to iterpret some of variables impornatce.
I used the following command:
mts <- nnet(y=Y,x=X,size =4, rang = 0.1,
decay = 5e-4, maxit = 5000,linout=TRUE)
X is (m x n) Y is (m x 1)
And then I get the coeficients by:
Wts<-coef(mts)
b->h1 i1->h1
2009 Feb 18
1
Training nnet in two ways, trying to understand the performance difference - with (i hope!) commented, minimal, self-contained, reproducible code
Dear all,
Objective: I am trying to learn about neural networks. I want to see
if i can train an artificial neural network model to discriminate
between spam and nonspam emails.
Problem: I created my own model (example 1 below) and got an error of
about 7.7%. I created the same model using the Rattle package (example
2 below, based on rattles log script) and got a much better error of
about
2003 Jul 16
1
Help on NNET
Hi, Dear all,
I am just starting using R in my work and got some trouble to figure out some of the errors. Can anybody help me?
The following is the script:
read.csv('pupil.txt',header=TRUE,sep='\t')->pupil
samp<-c(1:50, 112:162, 171:220, 228:278)
pupil.nn2 <- nnet(Type ~ ., data = pupil, subset = samp, size = 2, rang = 0.1, decay = 5e-4, maxit = 200)
2006 Mar 10
1
need help in tune.nnet
Dear R people,
I want to use the tune.nnet function of e1071 package to tune nnet .
I am unable to understand the parameters of tune.nnet from the e1071 pdf
document.
I have performed nnet on a traindata and want to test it for class
prediction with a testdata.
I want to know the values of size,decay,range etc. parameters for which
the prediction of testdata is best.
Can anyone please tell me
2009 Jun 07
1
Inf in nnet final value for validation data
Hi,
I use nnet for my classification problem and have a problem concerning the calculation of the final value for my validation data.(nnet only calculates the final value for the training data). I made my own final value formula (for the training data I get the same value as nnet):
# prob-matrix
pmatrix <- cat*fittedValues
tmp <- rowSums(pmatrix)
# -log likelihood
2009 Jul 24
1
nnet library and FANN package'm
Hello !
I'd like to know to which of the FANN package network corresponds the R nnet
network ?
In more details, what is the R nnet activation function, what is the
training algorithm (rprop, quickprop, ...) ? Also, it seems that the R nnet
"decay" parameter in nnet corresponds to the "learning_rate" parameter in
FANN. Correct ?
Many thanks in advance !
Luc Moulinier
2005 Oct 11
1
an error in my using of nnet
Hi, there:
I am trying nnet as followed:
> mg.nnet<-nnet(x=trn3[,r.v[1:100]], y=trn3[,209], size=5, decay = 5e-4,
maxit = 200)
# weights: 511
initial value 13822.108453
iter 10 value 7408.169201
iter 20 value 7362.201934
iter 30 value 7361.669408
iter 40 value 7361.294379
iter 50 value 7361.045190
final value 7361.038121
converged
Error in y - tmp : non-numeric argument to binary operator
2010 Jun 17
0
help with neural network nnet package
HI, Dear R community,
I am using the nnet to fit a neural network model to do classification on
binary target variable (0, 1). I am using the following codes:
nnet.fit<-nnet(as.factor(out) ~ ., data=train, size=5, rang=0.3,
decay=5e-4, maxit=500)
I want to know what is the activation function for the original inputs, is
it sigmoid activation function?
and what is the output activation