Displaying 13 results from an estimated 13 matches similar to: "Failing to install the rgl package"
2006 Feb 02
4
How to force a vector to be column or row vector?
Hi all,
I tended to use rbind, or cbind to force a vector be be deemed as a column
or row vector. This is very important if I want to do things like u' * A *
u, where u' is a row vector and u is a column vector, regardless of what
originall format the "u" is... I want to recast it to column vector or row
vector... How can I do that?
2005 Feb 10
2
testing slopes different than a given value
In a multiple linear regression with two independent
variables is there any function in R to test for the
coefficients being different than some given values?
Example:
x1<-rnorm(100)
x2<-rnorm(100)
y<-3+0.6*x1+0.3*x2
lm(y~x1+x2)
Obtain a test for the coefficients for x1 being
different than 0.6 and for x2 different than 0.3
Thanks
Manuel
2009 Jul 30
0
Constrained MLE of fixed mean Singh-Maddala distribution
INTRODUCTION TO THE PROBLEM
I am trying to fit a distribution to a dataset. The distribution that I
am currently considering is the (3-parameter) Singh-Maddala (Burr)
distribution. The final model will fix the mean of the distribution to a
given value and estimate the remaining parameters accordingly; however,
the code provided below ignores this. For this distribution the three
parameters
2009 Jul 31
0
MLE estimation of constrained mean Singh-Maddala distribution
INTRODUCTION TO THE PROBLEM
I am trying to fit a distribution to a dataset. The distribution that I
am currently considering is the (3-parameter) Singh-Maddala (Burr)
distribution. The final model will fix the mean of the distribution to a
given value and estimate the remaining parameters accordingly; however,
the code provided below ignores this. For this distribution the three
parameters
2007 Oct 17
1
y_hat
Hello,
suppose one has the following values
x1 <- rnorm(10,5,1)
x2 <- rgamma(10,5,1)
y <- rnorm(10,4,1)
mydat <- data.frame(y,x1,x2)
then one can use glm like
mod <- glm(y~x1+x2, data=mydat, family=gaussian)
But how could I estimate y_hat?
Thanks alot!
Sam
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2009 Feb 19
1
matrix computation???
Hello
Can anyone tell me what I am doing wrong below? My Y and y_hat are the same.
A<-scale(stackloss)
n1<- dim(A)[1];n2<-dim(A)[2]
X<-svd(A)
Y<- matrix(A[,"stack.loss"],nrow=n1)
Y
y_hat <-matrix((X$u%*% t(X$u))%*%Y,nrow=n1,byrow=T)
y_hat
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2010 Jun 23
1
Estimate of variance and prediction for multiple linear regression
Hi, everyone,
Night. I have three questions about multiple linear regression in R.
Q1:
y=rnorm(10,mean=5)
x1=rnorm(10,mean=2)
x2=rnorm(10)
lin=lm(y~x1+x2)
summary(lin)
## In the summary, 'Residual standard error: 1.017 on 7 degrees of freedom',
1.017 is the estimate of the constance variance?
Q2:
beta0=lin$coefficients[1]
beta1=lin$coefficients[2]
beta2=lin$coefficients[3]
2006 Jul 11
1
test regression against given slope for reduced major axis regression (RMA)
Hi,
for testing if the slope of experimental data differs from a
given slope I'm using the function
"test_regression_against_slope" (see below).
I am now confronted with the problem that I have data which
requires a modelII regression (also called reduced major axes
regression (RMA) or geometric mean regression). For this I use
the function "modelII" (see below).
What
2010 Mar 25
1
Manually calculate SVM
Hi,
I'm learning more about SVMs and kernels in general. I've gotten used
to using the svm function in the e1071 package. It works great.
Now, I want to do/learn some more interesting stuff. (Perhaps my own
kernel and/or scoring system). So I want to better understand
1) how calculation of the kernel happens.
2) how to calculate the predicted value (y_hat) given a list of support
2005 Dec 05
1
Help
Hi R-Users,
I apologize if it is too simple question for all. I have a multivariate
dataset having 7 variables as independent and 1 dependent variable. 248
data points are there. I want to do out sample forecast first
considering 156 points. So I'll have to start from 157th point and
calculate the 157th y_hat value. In this way it will go to 248th data
point. Can any one tell me how I can
2013 Apr 30
0
Extrafont package: Fonts are not successfully installed
Hi,
I am using Extrafont package to install more fonts for my graphs. My
primary graphic tool is ggplot2. I seem to have problem installing the
package, but could not pinpoint where it is.
I try to follow the instruction here:
https://github.com/wch/extrafont
I guess (but am not sure) the fonts are successfully installed.
Problem encountered:
1. The following line sometimes yields an
2005 Jul 20
1
predict.lm - standard error of predicted means?
Simple question.
For a simple linear regression, I obtained the "standard error of
predicted means", for both a confidence and prediction interval:
x<-1:15
y<-x + rnorm(n=15)
model<-lm(y~x)
predict.lm(model,newdata=data.frame(x=c(10,20)),se.fit=T,interval="confidence")$se.fit
1 2
0.2708064 0.7254615
2006 Jan 10
2
Obtaining the adjusted r-square given the regression coefficients
Hi people,
I want to obtain the adjusted r-square given a set of coefficients (without the intercept), and I don't know if there is a function that does it. Exist????????????????
I know that if you make a linear regression, you enter the dataset and have in "summary" the adjusted r-square. But this is calculated using the coefficients that R obtained,and I want other coefficients