Displaying 20 results from an estimated 2000 matches similar to: "apply lm function to dataset split by two variables"
2012 Feb 01
1
package sampling, function strata
Dear all,
I have to select 122 stratified random samples from a population of
>3900 cells. I have 41 strata and I have to draw a different number of
samples from them(between 2 and 8).
I have tried to apply the funtion strata following the instruction in
the manual:
strata(dataframe, stratanames=NULL, size, method=c("srswor"),
pik,description=TRUE)
but I get the error
2008 Dec 13
2
weird pasting of ".value" when list is returned
could someone explain why the name of FPVAL gets " .value" concatenated
onto it when the code below is run and temp is returned.
I've been trying to figure this out for too long. It doesn't matter when
I put the FPVAL in the return statement. It happens regardless of
whether it's first or last. Thanks.
f.lmmultenhanced <-
function(response, pred1, pred2)
{
2009 Oct 13
2
Linear Regression Question
Dear Sir or Madam,
I am a student at MSc Probability and Finance at Paris 6 University/
Ecole Polytechnique. I am using R and I can't find an answer to the
following question. I will be very thankful if you can answer it.
I have two vectors rendements_CAC40 and rendements_AlcatelLucent.
I use the lm function as follows, and then the sumarry function:
regression=lm(rendements_CAC40 ~
2009 Apr 05
4
extract the p value of F statistics from the lm class
Dear R users
I have run an regression and want to extract the p value of the F
statistics, but I can find a way to do that.
x<-summary(lm(log(RV2)~log(IV.m),data=b))
Call:
lm(formula = log(RV2) ~ log(IV.m), data = b[[11]])
Residuals:
Min 1Q Median 3Q Max
-0.26511 -0.09718 -0.01326 0.11095 0.29777
Coefficients:
Estimate Std. Error t value Pr(>|t|)
2010 Apr 26
1
Error in pf(q, df1, df2, lower.tail, log.p) : Non-numeric argument to mathematical function
inputfille
snpid indid genotype gvariable probeid gene geneexpression
rs1040480 CHB_NA18524 C/T 2 GI_19743926-I PTPRT 5.850586
rs1040480 CHB_NA18526 C/C 1 GI_19743926-I PTPRT 6.028641
rs1040480 CHB_NA18529 C/C 3 GI_19743926-I PTPRT 5.944392
rs1040481 CHB_NA18532 C/C 1 GI_19743926-I PTPRT 5.938578
rs1040481 CHB_NA18537 C/C 2 GI_19743926-I PTPRT 5.874439
rs1040481 CHB_NA18540 C/C 3 GI_19743926-I
2003 Jul 07
1
P-value for F from summary.lm (was RE: (no subject))
[Please use the subject line!]
In the help page for summary.lm, the "Value" section says that the returned
object has a component called "fstatistic", which has the F-statistic and
the associated numerator and denominator degrees of freedom. You can get
the p-value by something like:
fstat <- summary(speciallinearmodel)$fstatistic
pval <- pf(fstat[1], fstat[2],
2010 Nov 29
1
extracting P values from lm model
Hello
I am trying to get out of an lm model the fstatistics, however after I run the model I write
> names(Model)
and the fstatistic does not appear only these.
names(Model)
[1] "coefficients" "residuals" "effects" "rank" "fitted.values"
[6] "assign" "qr" "df.residual"
2011 Aug 15
2
Extracting information from lm results (multiple model runs)
Just to inform:
I posted that before in R-sig-ecology but as it might be interesting also for other useRs, I post it also to the general r-user list:
Hello Alexandre,
thank you very much. I also found another way to extract summarizing information from lm results over e.g. 1000 repeated model runs:
results2 <- t(as.data.frame(results))
summary(results2)
Although some questions popped up in
1999 Nov 23
1
p-value from lm
I'd like to automatically plot the p-value and r^2 of a linear model.
I know that I can extract r^2 with
foo <- lm(y~x)
a <- summary(foo)
a$r.squared
I can't find any similar functionality to obtain the p-value based on
the ftest
a$fstatistic returns the actual f-test and df, but not the p-value.
Any thoughts?
Thanks,
Adam
using R-0.65.1
Win32
2011 May 19
2
Error in svg() : cairo-based devices are not supported on this build
Hello,
Sorry if it is not the right place..
I installed R-2.13.0 on a x86_64 linux server.
All went fine, but the svg() function yells:
> svg()
Error in svg() : cairo-based devices are not supported on this build
I have the Cairo, cairoDevice, RSvgDevice packages installed, and running.
> Cairo.capabilities()
png jpeg tiff pdf svg ps x11 win
TRUE TRUE TRUE TRUE TRUE
2006 Jul 26
1
.Call question
Writing R Ext says to treat R objects that are arguments to .Call as
read only (i.e. don't modify).
I have a long list of lists that and I want to avoid the overhead of a
copy in my C code. I would just like to modify some of the elements
of list by replacing them with elements of exactly the same size/type.
below is an example of the essence of the problem. This seems to work.
Is this
2016 Apr 29
2
lm() with spearman corr option ?
Hi,
A following function was kindly provided by GGally?s maintainer, Barret Schloerke.
function(data, mapping, ...) {
p <- ggplot(data = data, mapping = mapping) +
geom_point(color = I("blue")) +
geom_smooth(method = "lm", color = I("black"), ...) +
theme_blank() +
theme(panel.border=element_rect(fill=NA, linetype =
2005 Dec 09
3
retrieving p-values in lm
Dear list,
I want to retrieve the p-value of a two-polynomial regression. For a
one-polynomial lm I can easily do this with:
summary(lm(b~a, data=c)[[4]][[8]].
But how do I find the final p-value in the two-polynomial regression? Under
$coefficients I don't find it
Any suggestions?
Patrick
alt <-(2260,2183,2189,1930,2435,
2000,2100,2050,2020,2470,
1700,2310,2090,1560,2060,
2011 Aug 04
3
functions on rows or columns of two (or more) arrays
I realize this should be simple, but even after reading over the several
help pages several times, I still cannot decide between the myriad "apply"
functions to address it. I simply want to apply a function to all the rows
(or columns) of the same index from two (or more) identically sized arrays
(or data frames).
For example:
> a=matrix(1:50,nrow=10)
>
2011 Oct 31
1
Significance of trend
Hi everyone,
I'm trying to determine the significance of a trendline. From my internet
search months ago, I came across the following post. I modified tim and
dat for simiplicity.
tim <- 1:10
dat <- c(0.17, 1.09 ,0.11, 0.82, 0.23, 0.38 ,2.47 ,0.41 ,0.75, 1.44)
fstat <- summary(lm(dat~tim))$fstatistic
p.val <-
2012 Aug 29
1
LDAP access to Samba 4
Hello,
I am currently migrating from OpenLDAP to Samba 4 PDC, and I have a webpage (PHP/Apache) available for users so that they can change their password on the existing LDAP server.
I attempted to adjust that script to change the password on the Samba 4 AD controller, but I get a "cannot connect" error to LDAP. The web server the password script is running on is not on the same
2011 Oct 24
3
extract the p value
OK, what is the trick to extracting the overall p value from an lm object?
It shows up in the summary(lm(model)) output but I can't seem to extract it:
> test2 = apply(aa, 1, function(x) summary(lm(x[,1] ~ 0 + x[,3] + x[,6])))
> test2[[1]]
Call:
lm(formula = x[, 1] ~ 0 + x[, 3] + x[, 6])
[omitted summary output]
F-statistic: 40.94 on 2 and 7 DF, p-value: 0.0001371
It does not seem
2014 Feb 04
1
How to change objectSid?
Hi,
I'm trying to modify the objectSid of a group using python-ldap. I've
found that I need a server control to do it but doesn't work. The code
that I'm using:
modlist = [ (ldap.MOD_REPLACE, 'objectSid', s3sid_packed) ]
LDB_CONTROL_PROVISION_OID = "1.3.6.1.4.1.7165.4.3.16"
LDB_CONTROL_RELAX_OID = "1.3.6.1.4.1.4203.666.5.12"
2012 Jun 05
1
nls: how do you know if the model is significant?
Hi all,
I'm struggling with nls. How do you know if your model is significant? For a
lm, you get a p-value, but you don't get it for a nls. Is there a way to
calculate it?
For a lm I use this:
a<-summary(lm(model ~obs))
f.stat<-a$fstatistic
p.value<-1-pf(f.stat["value"],f.stat["numdf"],f.stat["dendf"])
Is there something similar for a nls?
2009 Feb 24
1
Box.test reference correction (PR#13554)
Full_Name: Peter Solymos
Version: 2.8.1
OS: Windows
Submission from: (NULL) (129.128.141.92)
The help page of the Box.test function (stats) states that the Ljung-Box test
was published in:
Ljung, G. M. and Box, G. E. P. (1978), On a measure of lack of fit in time
series models. Biometrika 65, 553--564.
The page numbers are incorrect. The correct citation should be as follows:
Ljung, G. M.