Displaying 20 results from an estimated 300 matches similar to: "Ridge regression"
2013 Apr 27
1
Selecting ridge regression coefficients for minimum GCV
Hi all,
I have run a ridge regression as follows:
reg=lm.ridge(final$l~final$lag1+final$lag2+final$g+final$u,
lambda=seq(0,10,0.01))
Then I enter :
select(reg) and it returns: modified HKB estimator is 19.3409
modified L-W estimator is 36.18617
smallest value of GCV at 10
I think it means that it is advisable to
2013 Apr 26
1
Regression coefficients
Hi all,
I have run a ridge regression as follows:
reg=lm.ridge(final$l~final$lag1+final$lag2+final$g+final$g+final$u,
lambda=seq(0,10,0.01))
Then I enter :
select(reg) and it returns: modified HKB estimator is 19.3409
modified L-W estimator is 36.18617
smallest value of GCV at 10
I think it means that it is
2012 Feb 21
0
BHHH algorithm on duration time models for stock prices
I am currently trying to find MLE of a function with four parameters. My codes run well but i don't get the results. I get the following message:
BHHH maximisation
Number of iterations: 0
Return code: 100
Initial value out of range.
I don't know this is so because of the way i have written my loglikelihood or what.
The loglikelihood
LogLik<-function(param){
beta_1<-param[1]
2002 Jun 20
1
Possible bug with glm.nb and starting values (PR#1695)
Full_Name: Ben Cooper
Version: 1.5.0
OS: linux
Submission from: (NULL) (134.174.187.90)
The help page for glm.nb (in MASS package) says that it takes "Any other
arguments for the glm() function except family"
One such argument is start "starting values for the parameters in the linear
predictor."
However, when called with starting values glm.nb returns:
Error in
2012 Feb 03
1
A question on Unit Root Test using "urca" toolbox
Hello,
I have a question on unit root test with urca toolbox.
First, to run a unit root test with lags selected by BIC, I type:
> CPILD4UR<-ur.df(x1$CPILD4[5:nr1], type ="drift", lags=12, selectlags ="BIC")
> summary(CPILD4UR)
The results indicate that the optimal lags selected by BIC is 4.
Then I run the same unit root test with drift and 4 lags:
2008 May 22
1
How to account for autoregressive terms?
Hi,
how to estimate a the following model in R:
y(t)=beta0+beta1*x1(t)+beta2*x2(t)+...+beta5*x5(t)+beta6*y(t-1)+beta7*y(t-2)+beta8*y(t-3)
1) using "lm" :
dates <- as.Date(data.df[,1])
selection<-which(dates>=as.Date("1986-1-1") & dates<=as.Date("2007-12-31"))
dep <- ts(data.df[selection,c("dep")])
indep.ret1
1999 May 06
0
image weirdness
I am using R 63.0.
Now let's try this simple image plot.
Here is the data file:
============================
lag1 lag2 cif2d
1 1 11
1 2 12
1 3 13
2 1 21
2 2 22
2 3 23
3 1 31
3 2 32
3 3 33
====================
data<-read.table("~/r/rt/data/unif/junk.out",header=TRUE)
x<-unique(data$lag1)
y<-unique(data$lag2)
z<-matrix(data$cif2d,length(y),length(x))
At this point, see
1999 May 06
0
matrix weirdness
I am using R on unix version 63.0
I am doing an image plot of the following data file:
================================
lag1 lag2 cif2d
0.000 0.000 NaN
0.000 1.000 0.500000
0.000 2.000 0.489831
0.000 3.000 0.492986
0.000 4.000 0.493409
0.000 5.000 0.492727
0.000 6.000 0.494485
1.000 0.000 0.500000
1.000 1.000 NaN
1.000 2.000 0.495098
1.000 3.000 0.489831
1.000 4.000 0.492986
1.000 5.000
2013 May 02
2
saving a matrix
Hi all,
In my data analysis,
I have created a random matrix M ( of order 500 X 7).
I want to use the same matrix when I start a new session, or suppose I want
to send this matrix to one of my friends (because this matrix is randomly
generated, and I dont want to use any other 500X7 matrix randomly generated
by R).
How can I save and call this matrix in the later sessions as well?
Appreciate
2012 Dec 03
2
How to rename the columns of as.table
Hello guys .. I would like to have some help about as.table .
I made a table with the autocorrelations of the returns whit 10 lags and i
get this :
autocorrelazione2 <- as.table(c((cor(r2[-1151,],lag(r2))),(cor(r2[-
c(1151,1150),],lag(r2, k=2))),(cor(r2[- c(1151,1150,1149),],lag(r2,
k=3))),(cor(r2[- c(1151,1150,1149,1148),],lag(r2, k=4))),(cor(r2[-
c(1151,1150,1149,1148,1147),],lag(r2,
2013 Apr 25
1
Bootstrapping in R
Hi all,
1>i have 3 vectors a,b and c, each of length 25....... i want to define a
new data frame z such that z[1] = (a[1] b[1] c[1]), z[2] = (a[2] b[2] c[2])
and so on...how do i do it in R
2> Then i want to draw bootstrap samples from z.
Kindly suggest how i can do this in R.
Thanks,
Preetam
--
Preetam Pal
(+91)-9432212774
M-Stat 2nd Year,
2016 Apr 30
1
Declaring All Variables as Factors in GLM()
Hi guys,
I am running glm(y~., data = history,family=binomial)-essentially, logistic
regression for credit scoring (y = 0 or 1). The dataset 'history' has 14
variables, a few examples:
history <- read.csv("history.csv". header = TRUE)
1> 'income = 100,200,300 (these are numbers in my dataset; however
interpretation is that these are just tags or labels,for every
2013 Apr 29
1
Arma - estimate of variance of white noise variables
Hi all,
Suppose I am fitting an arma(p,q) model to a time series y_t.
So, my model should contain (q+1) white noise variables.
As far as I know, each of them should have the same variance.
How do I get the estimate of this variance by running the arma(y) function
(or is there any other way)?
Appreciate your help.
Thanks,
Preetam
--
Preetam Pal
(+91)-9432212774
M-Stat 2nd Year,
2013 Apr 30
1
ADF test --time series
Hi all,
I was running the adf test in R.
CODE 1:
adf.test(data$LOSS)
Augmented Dickey-Fuller Test
data: data$LOSS
Dickey-Fuller = -1.9864, Lag order = 2, p-value = 0.5775
alternative hypothesis: stationary
CODE 2:
adf.test(diff(diff(data$LOSS)))
Augmented Dickey-Fuller Test
data: diff(diff(data$LOSS))
Dickey-Fuller = -6.9287, Lag order = 2, p-value = 0.01
alternative
2013 May 02
2
ARMA with other regressor variables
Hi,
I want to fit the following model to my data:
Y_t= a+bY_(t-1)+cY_(t-2) + Z_t +Z_(t-1) + Z_(t-2) + X_t + M_t
i.e. it is an ARMA(2,2) with some additional regressors X and M.
[Z_t's are the white noise variables]
How do I find the estimates of the coefficients in R?
And also I would like to know what technique R employs to find the
estimates?
Any help is appreciated.
Thanks,
2013 May 04
2
Lasso Regression error
Hi all,
I have a data set containing variables LOSS, GDP, HPI and UE.
(I have attached it in case it is required).
Having renamed the variables as l,g,h and u, I wish to run a Lasso
Regression with l as the dependent variable and all the other 3 as the
independent variables.
data=read.table("data.txt", header=T)
l=data$LOSS
h=data$HPI
u=data$UE
g=data$GDP
matrix=data.frame(l,g,h,u)
2013 Apr 25
2
Selecting and then joining data blocks
Hi all,
I have 4 matrices, each having 5 columns and 4 rows .....denoted by
B1,B2,B3,B4.
I have generated a vector of 7 indices, say (1,2,4,3,2,3,1} which refers to
the index of the matrices to be chosen and then appended one on the top of
the next: like, in this case, I wish to have the following mega matrix:
B1over B2 over B4 over B3 over B2 over B3 over B1.
1> How can I achieve this?
2013 May 02
1
warnings in ARMA with other regressor variables
Hi all,
I want to fit the following model to my data:
Y_t= a+bY_(t-1)+cY_(t-2) + Z_t +Z_(t-1) + Z_(t-2) + X_t + M_t
i.e. it is an ARMA(2,2) with some additional regressors X and M.
[Z_t's are the white noise variables]
So, I run the following code:
for (i in 1:rep) { index=sample(4,15,replace=T)
final<-do.call(rbind,lapply(index,function(i)
2009 Jun 04
0
help needed with ridge regression and choice of lambda with lm.ridge!!!
Hi,
I'm a beginner in the field, I have to perform the ridge regression with lm.ridge for many datasets, and I wanted to do it in an automatic way.
In which way I can automatically choose lambda ?
As said, right now I'm using lm.ridge MASS function, which I found quite simple and fast, and I've seen that among the returned values there are HKB estimate of the ridge constant and L-W
2013 May 09
0
ARMA(p,q) prediction with pre-determined coefficients
I have the following time series model for prediction purposes
*Loss_t = b1* Loss_(t-1) + b2*GDP_t + b3*W_(t-1)* where W_t is the
usual white noise variable.
So this is similar to ARMA(1,1) except that it also contains an extra
predictor, GDP at time t.
I have only 20 observations on each variable except GDP for which I know
till 100 values.
And most importantly,I have also calculated