similar to: finding interpolated values along an empirical parametric curve

Displaying 14 results from an estimated 14 matches similar to: "finding interpolated values along an empirical parametric curve"

2011 Nov 29
2
format numbers without leading or trailing 0s
A simple question, but I can't find something to do what I want: Given: a vector of numbers, like lambda <- c(0, 0.005, 0.01, 0.02, 0.04, 0.08) Desired: format them in minimal space for use as plot labels, ie, without leading or tailing 0s. For this example: lambdaf <- c("0", .005", ".01", ".02", ".04", ".08") -- Michael
2012 Dec 27
1
Ridge Regression variable selection
Unlike L1 (lasso) regression or elastic net (mixture of L1 and L2), L2 norm regression (ridge regression) does not select variables. Selection of variables would not work properly, and it's unclear why you would want to omit "apparently" weak variables anyway. Frank maths123 wrote > I have a .txt file containing a dataset with 500 samples. There are 10 > variables. > >
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
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
2009 Aug 21
1
applying summary() to an object created with ols()
Hello R-list, I am trying to calculate a ridge regression using first the *lm.ridge()* function from the MASS package and then applying the obtained Hoerl Kennard Baldwin (HKB) estimator as a penalty scalar to the *ols()* function provided by Frank Harrell in his Design package. It looks like this: > rrk1<-lm.ridge(lnbcpc ~ lntex + lnbeerp + lnwinep + lntemp + pop, subset(aa,
2011 Aug 06
0
ridge regression - covariance matrices of ridge coefficients
For an application of ridge regression, I need to get the covariance matrices of the estimated regression coefficients in addition to the coefficients for all values of the ridge contstant, lambda. I've studied the code in MASS:::lm.ridge, but don't see how to do this because the code is vectorized using one svd calculation. The relevant lines from lm.ridge, using X, Y are:
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
2005 Aug 24
1
lm.ridge
Hello, I have posted this mail a few days ago but I did it wrong, I hope is right now: I have the following doubts related with lm.ridge, from MASS package. To show the problem using the Longley example, I have the following doubts: First: I think coefficients from lm(Employed~.,data=longley) should be equal coefficients from lm.ridge(Employed~.,data=longley, lambda=0) why it does not happen?
2013 Apr 30
0
Ridge regression
Hi all, I have run a ridge regression on a data set 'final' 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
2011 Aug 23
1
obtaining p-values for lm.ridge() coefficients (package 'MASS')
Dear all I'm familiarising myself with Ridge Regressions in R and the following is bugging me: How does one get p-values for the coefficients obtained from MASS::lm.ridge() output (for a given lambda)? Consider the example below (adapted from PRA [1]): > require(MASS) > data(longley) > gr <- lm.ridge(Employed ~ .,longley,lambda = seq(0,0.1,0.001)) > plot(gr) > select(gr)
2013 Mar 07
1
create vector from indices interpolated values
Readers, Is it possible to create a plot command based upon the indices of missing values in a data set? dataset1<-read.table(text=' 10 2 20 NA 30 5 40 7 50 NA 60 NA 70 2 80 6 90 NA 100 9 ') dataset2<-read.table(text=' 0.2 0.4 0.1 0.9 0.2 0.3 1.1 0.7 0.9 0.6 0.4 ') The 'approx' function is used to obtain the interpolated values for 'NA' in dataset1.
2008 Dec 21
1
How can I get the interpolated data?
Hello,everybody! I am a beginner of R. And I want to ask a question. If anybody would help me, thank you very much ahead. I want to plot something like a response surface, and I find the "rsm" package. Some commands are like this: #code head library(rsm) CR = coded.data(ChemReact, x1 ~ Time, x2 ~ Temp) CR.rsm = rsm(Yield ~ SO(x1,x2), data = CR) summary(CR.rsm) contour(CR.rsm,x1~x2)
2001 Sep 05
2
Replacing NAs with interpolated values
Hi there, I've got this vector: -84 -87 -90 -90 -89 -86 NA NA NA NA NA NA NA NA NA NA NA NA -96 -99 -100 -99 -96 -92 -89 -87 -87 -88 -90 -92 -94 -95 -96 -97 -97 -97 -96 -95 Is there a function in R which replaces the NAs with "interpolated" values between -86 and -96? Thanks, Sven
2013 Feb 11
2
Inserting rows of interpolated data
Dear help list - I have light data with 5-min time-stamps. I would like to insert four 1-min time-stamps between each row and interpolate the light data on each new row. To do this I have come up with the following code: lightdata <- read.table("Test_light_data.csv", header = TRUE, sep = ",") # read data file into object "lightdata" library(chron) mins <-