Displaying 11 results from an estimated 11 matches for "lmobj".
2010 Jul 20
1
Transformation of Y changes the 'lm' object?
Hi R,
This is a problem, which I have tried to present in a simple way:
Let,
x1=1:10
x2=2:11
y=2+3*x1
lm_obj=lm(y~x1+x2)
lm_obj
step(lm_obj) # Step function for the first time
y=y^0.1
lm_obj
step(lm_obj) #Step function after a transformation on Y, but 'lm_obj' is not modified.
The two step function behave differently. The first one is before the
2007 Mar 20
5
abline within data range
Dear R helpers,
I would like to have abline, for a lm model for
example, lying within data range. Do you know how to
get it?
Thank in advance
Nguyen D Nguyen
#CODE
x<- rnorm(200, 35,5)
y<- rnorm(200, 0.87,0.12)
plot(y~x, xlim=c(0,50), pch=17, bty="l")
abline(lm(y~x))
# I would like abline is between min(x) and max(x)
[[alternative HTML version deleted]]
1997 Oct 17
1
R-beta: more model.matrix
I am trying to show some techniques to my graduate regression class.
The textbook mentioned using bootstrap samples of regression
coefficients for assessing variability. I decided to show them
reasonably effective ways of doing the resampling.
The following is a function I wrote to create bootstrap samples of
coefficients from a fitted linear regression model.
bsCoefSample <-
##
1997 Aug 25
0
R-alpha: R FAQ
...39;' created when cube() was invoked is also
looked in:
R> cube(2)
[1] 8
The following more `realistic' example illustrating the differences in
scoping is due to Thomas Lumley <thomas@biostat.washington.edu>. The
function
jackknife.lm <- function(lmobj) {
n <- length(resid(lmobj))
jval <- t(apply(as.matrix(1:n), 1,
function(i) coef(update(lmobj, subset = -i))))
(n - 1) * (n - 1) * var(jval) / n
}
does something useful in R, but does not work in S. In order to make
it work in S...
2009 Jan 30
2
Regression
Hello, I have problem
I have a, and b in regression
then I can't plot x,y with (and) a, b lines
can you help me ?
thx
[[alternative HTML version deleted]]
2009 Sep 28
4
Running an ANOVA with a BY
I have a simple 1 way anova coded like
summary(ANOVA1way <- aov(Value ~ WellID, data = welldata))
How can I use the BY function to do this ANOVA for each group using another
variable in the dataset?? I tried coding it like this, but it doesn't seem
to work.
summary(ANOVA1way <- by(welldata, Analyte, function(x) aov(Value ~ WellID,
data = welldata)))
In SAS I would code it like this:
1997 Dec 09
3
R-beta: R FAQ v0.60
...' created when cube() was invoked is also
looked in:
R> cube(2)
[1] 8
The following more `realistic' example illustrating the differences in
scoping is due to Thomas Lumley <thomas at biostat.washington.edu>. The
function
jackknife.lm <- function(lmobj) {
n <- length(resid(lmobj))
jval <- t(apply(as.matrix(1:n), 1,
function(i) coef(update(lmobj, subset = -i))))
(n - 1) * (n - 1) * var(jval) / n
}
does something useful in R, but does not work in S. In order to make
it work in S...
1997 Dec 09
3
R-beta: R FAQ v0.60
...' created when cube() was invoked is also
looked in:
R> cube(2)
[1] 8
The following more `realistic' example illustrating the differences in
scoping is due to Thomas Lumley <thomas at biostat.washington.edu>. The
function
jackknife.lm <- function(lmobj) {
n <- length(resid(lmobj))
jval <- t(apply(as.matrix(1:n), 1,
function(i) coef(update(lmobj, subset = -i))))
(n - 1) * (n - 1) * var(jval) / n
}
does something useful in R, but does not work in S. In order to make
it work in S...
1997 Dec 09
3
R-beta: R FAQ v0.60
...' created when cube() was invoked is also
looked in:
R> cube(2)
[1] 8
The following more `realistic' example illustrating the differences in
scoping is due to Thomas Lumley <thomas at biostat.washington.edu>. The
function
jackknife.lm <- function(lmobj) {
n <- length(resid(lmobj))
jval <- t(apply(as.matrix(1:n), 1,
function(i) coef(update(lmobj, subset = -i))))
(n - 1) * (n - 1) * var(jval) / n
}
does something useful in R, but does not work in S. In order to make
it work in S...
2010 Nov 26
0
contour figure from rsm
Dear r users,
I wanted to perform contour figure from response surface model result. I typed this:
> model = rsm (Index ~ SO(NV, SKLON, pH), bonita)
> summary(model)
> par(mfrow = c(2, 3))
> contour (model, ~NV+SKLON+pH)
However, I got the error answer as follows:
Error in lmobj$data[, nm] :
object of type 'environment' is not subsettable
Has someone any suggestions to solve this?
Thanks to all,
Michal
_________________________________________________________
Michal Bosela
National Forest Centre - Forest Research Institute Zvolen
Department of Forest Inventory...
2012 Jul 26
2
Working with Numbers generated from Regression Output
Hi,
I have a query on regression output generated by R.
> result=lm( Y~X , data=trail)
> summary(result)
After running this 2 statements the following output is generated.
Call:
lm(formula = Y ~ X, data = trail)
Residuals:
Min 1Q Median 3Q Max
-245.30 -90.77 -30.30 54.99 532.78
Coefficients:
Estimate Std. Error t value Pr(>|t|)