Displaying 20 results from an estimated 10000 matches similar to: "Neural Net Validation Sub Set"
2008 Apr 26
1
Variables selection in Neural Networks
Hi folks,
I want to apply a neural network to a data set to classify the observations
in the different classes from a concrete response variable. The idea is to
prove different models from network modifying the number of neurons of the
hidden layer to control overfitting. But, to select the best model how I can
choose the relevant variables? How I can eliminate those that are not
significant for
2009 May 29
1
Backpropagation to adjust weights in a neural net when receiving new training examples
I want to create a neural network, and then everytime it receives new data,
instead of creating a new nnet, i want to use a backpropagation algorithm
to adjust the weights in the already created nn.
I'm using nnet package, I know that nn$wts gives the weights, but I cant
find out which weights belong to which conections so I could implement the
backpropagation algorithm myself.
But if anyone
2009 May 27
3
Neural Network resource
Hi All,
I am trying to learn Neural Networks. I found that R has packages which can help build Neural Nets - the popular one being AMORE package. Is there any book / resource available which guides us in this subject using the AMORE package?
Any help will be much appreciated.
Thanks,
Indrajit
2013 May 20
0
Neural network: Amore adaptative vs batch why the results are so different?
I am using the iris example came with nnet package to test AMORE. I can see
the outcomes are similar to nnet with adaptative gradient descent. However,
when I changed the method in the newff to the batch gradient descent, even
by setting the epoch numbers very large, I still found all the iris
expected class=2 being classified as class=3. In addition, all those
records in the outcomes (y) are the
2012 Jan 24
0
Problem training a neural network with "neuralnet" library
Hi,
I am having difficulty in training a neural network using the package "neuralnet". My neural network has 2 input neurons (covariates), 1 hidden layer with 2 hidden neurons and 2 output neurons (responses). I am training my neural network with a dataset that has been transformed so that each column is of type "numeric". The difficulty I am facing is that the responses of
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 23
1
Activation Functions in Package Neural
Hi,
I am trying to build a VERY basic neural network as a practice before
hopefully increasing my scope. To do so, I have been using package "neural"
and the MLP related functions (mlp and mlptrain) within that package.
So far, I have created a basic network, but I have been unable to change the
default activation function. If someone has a suggestion, please advise.
The goal of the
2009 May 24
2
accuracy of a neural net
Hi. I started with a file which was a sparse 982x923 matrix and where the
last column was a variable to be predicted. I did principle component
analysis on it and arrived at a new 982x923 matrix.
Then I ran the code below to get a neural network using nnet and then wanted
to get a confusion matrix or at least know how accurate the neural net was.
I used the first 22 principle components only for
2005 Feb 08
1
Toying with neural networks
Hello all,
Ive been playing with nnet (package 'nnet') and Ive come across this
problem. nnet doesnt seems to like to have more than 1000 weights. If I
do:
> data(iris)
> names(iris)[5] <- "species"
> net <- nnet(species ~ ., data=iris, size=124, maxit=10)
# weights: 995
initial value 309.342009
iter 10 value 21.668435
final value 21.668435
stopped after 10
2010 Dec 10
2
Help..Neural Network
Hi all,
I am trying to develop a neural network with single target variable and 5
input variables to predict the importance of input variables using R. I used
the packages nnet and RSNNS. But unfortunately I could not interpret the out
put properly and the documentation of that packages also not giving proper
direction. Please help me to find a good package with a proper documentation
for neural
2003 Jul 11
2
Nonliner Rgression using Neural Nnetworks
Hi,
I am an old hand at chemistry but a complete beginner at statistics
including R computations.
My question is whether you can carry out nonlinear
multivariate regression analysis in R using neural networks, where the
output variable can range from -Inf to + Inf., unlike discriminant
analysis where the output is confined to one or zero. The library nnet
seems to work only in the latter
2014 Jan 13
1
Ayuda con Neuralnet
Hola a todos, en primer lugar quería agradecer la ayuda recibida desde el foro con respecto a la creación de una red neuronal. Estoy utilizando el paquete Neuralnet, que me parece que es bastante bueno, pero tengo el problema que soy incapaz de hacer las predicciones del modelo. Sé que se hace con el comando "compute", pero no encuentro ningún ejemplo de cómo hacerlo. ¿Alguien me puede
2007 Feb 23
2
Neural Net forecasting
Are there any packages in R that are suitable for doing time series
forecasting using neural networks? I have looked in the nnet package and
neural package and they both seem geared towards classification.
thanks,
Spencer
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2010 Dec 10
2
Need help on nnet
Hi,
Am working on neural network.
Below is the coding and the output
> library (nnet)
> uplift.nn<-nnet (PVU~ConsumerValue+Duration+PromoVolShare,y,size=3)
# weights: 16
initial value 4068.052704
final value 3434.194253
converged
> summary (uplift.nn)
a 3-3-1 network with 16 weights
options were -
b->h1 i1->h1 i2->h1 i3->h1
16.64 6.62 149.93
2010 Jan 03
2
Artificial Neural Networks
Hi! I am studying to use some R libraries which are applied for working with artificial neural neworks (amore, nnet). Can you recommend some useful, reliable and easy to get example data to use in R for creating and testing a neural network?
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2004 Jun 11
1
probabilistic neural networks
Hi,
I'm working on a classification problem and one of the methods I'd
like to use are neural networks. I've been using nnet to build a
classification network. However I would like to have the probabilities
associated with the prediction.
Are there any implementations of probabilistic neural networks available
in R?
thanks,
2003 Aug 20
1
Neural Networks in R
Hello!
We are a group of three students at Bielefeld University currently working
on a statistical projects about neural networks. Within the framework of this
project we are supposed to use the nnet-function in R and explain how it
works. Since anyone of us has much experience in using R we hoped to find some
information on your homepage. Unfortunatelly, we haven't been very successfull
so
2009 Mar 10
1
find the important inputs to the neural network model in "nnet" package
Hi, I have a binary variable and many explanatory variables and I want to
use the package "nnet" to model these data, (instead of logistic regression).
I want to find the more effective variables (inputs to the network) in
the neural network model. how can I do this?
thanks.
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2012 Sep 21
0
using neural network in R (nnet)
Hi all,
I have considered neural network to classify the health status of the cow.
I found a very neatly written R codes for classification method in
here<http://home.strw.leidenuniv.nl/~jarle/IAC/RRoutines/classification-example.R>
.
It would be very helpful if you can answer some of the questions, that I am
struggling with,
I have set of time series data from different animals, I use
2011 Jan 05
0
Nnet and AIC: selection of a parsimonious parameterisation
Hi All,
I am trying to use a neural network for my work, but I am not sure about my
approach to select a parsimonious model. In R with nnet, the IAC has
not been defined for a feed-forward neural network with a single hidden layer.
Is this because it does not make sens mathematically in this case?
For example, is this pseudo code sensible?
Thanks in advance for your help. I am sorry if this