Displaying 20 results from an estimated 6000 matches similar to: "Question on summing rows within nested variable"
2009 Mar 04
2
Selecting one row or multiple rows per ID
Hi,
Could someone help with coding this in R?
I need to select one row per patient i in clinic j. The data is organized similar to that shown below.
Two columns - patient i in column j identify each unique patient. There are two columns on outcome. Some patients have multiple rows with each row representing one visit, coded for in the column, visit. Some patients have just one row indicating
2009 Apr 08
2
Null-Hypothesis
Hello R users,
I've used the following help two compare two regression line slopes.
Wanted to test if they differ significantly:
Hi,
I've made a research about how to compare two regression line slopes
(of y versus x for 2 groups, "group" being a factor ) using R.
I knew the method based on the following statement :
t = (b1 - b2) / sb1,b2
where b1 and b2 are the two slope
2011 Mar 18
1
Problem with Slope.test function
Hi all,
I need to test the significnce of difference between slopes of two regression lines and regression line with theoretical line. I try to use Slope.test function from emu package,
but an error occured...
library(emu)
d1<-data.frame(P1=c(1,2,3,5,7,8,9,13,14,15),
P2=c(1,2,5,8,11,13,15,15,18,24),
R=c(2,7,8,9,16,21,27,31,33,36)) # First data set
m1<-lm(R~P1+P2+P1*P2,data=d1) # Regr.
2009 Jan 27
3
How to compare two regression line slopes
Hi,
I've made a research about how to compare two regression line slopes
(of y versus x for 2 groups, "group" being a factor ) using R.
I knew the method based on the following statement :
t = (b1 - b2) / sb1,b2
where b1 and b2 are the two slope coefficients and sb1,b2 the pooled
standard error of the slope (b)
which can be calculated in R this way:
> df1 <-
2003 Jul 30
2
Comparing two regression slopes
Hello,
I've written a simple (although probably overly roundabout) function to
test whether two regression slope coefficients from two linear models on
independent data sets are significantly different. I'm a bit concerned,
because when I test it on simulated data with different sample sizes and
variances, the function seems to be extremely sensitive both of these. I am
wondering if
2004 Jun 11
1
comparing regression slopes
Dear List,
I used rlm to calculate two regression models for two data sets (rlm
due to two outlying values in one of the data sets). Now I want to
compare the two regression slopes. I came across some R-code of Spencer
Graves in reply to a similar problem:
http://www.mail-archive.com/r-help at stat.math.ethz.ch/msg06666.html
The code was:
> df1 <- data.frame(x=1:10, y=1:10+rnorm(10))
2004 Apr 03
3
Seeking help for outomating regression (over columns) and storing selected output
Hello,
I have spent considerable time trying to figure out that which I am about to describe. This included searching Help, consulting my various R books, and trail and (always) error. I have been assuming I would need to use a loop (looping over columns) but perhaps and apply function would do the trick. I have unsuccessfully tried both.
A scaled down version of my situation is as follows:
2004 Feb 19
1
Comparing two regression slopes
I would suggest the method of Sokal and Rholf (1995) S. 498, using the F
test.
Below I repeat the analysis by Spencer Graves:
Spencer:
> df1 <- data.frame(x=1:3, y=1:3+rnorm(3))
> df2 <- data.frame(x=1:3, y=1:3+rnorm(3))
> fit1 <- lm(y~x, df1)
> s1 <- summary(fit1)$coefficients
> fit2 <- lm(y~x, df2)
> s2 <- summary(fit2)$coefficients
> db <-
2011 Nov 08
2
compare linear regressions
Hi,
I'm trying to compare two linear regressions. I'm using the
following approach:
##################
xx<-1:100
df1 <- data.frame(x = xx, y = xx * 2 + 30 + rnorm(n=length(xx),sd=10), g = 1)
df2 <- data.frame(x = xx, y = xx * 4 + 9 + rnorm(n=length(xx),sd=10), g = 2)
dta <- rbind(df1, df2)
dta$g <- factor(dta$g)
2015 Aug 27
3
RFC: alloca -- specify address space for allocation
Philip: I think there are two separate issues:
1) Handling GC pointers stored in stack locations -- tracking their liveness, reporting them to the GC. etc.
2) Treating pointers to stack locations as GC-pointers.
I think the two options that you presented here are for solving (1).
I'm trying to solve issue (2) using alloca in addrspace(1).
Basically, we want to create a pointer to a stack
2015 Aug 27
11
RFC: alloca -- specify address space for allocation
Currently, the alloca instruction always allocates in the generic address space (0).
This proposal is to extend the semantics of alloca instruction to allow allocation in any specified address space.
Proposed Syntax
<result> = alloca [inalloca] <type> [, <ty> <NumElements>] [, align <alignment>] [, addrspace <num>] ; yields type addrspace(num)*:result
2011 Mar 03
1
Applying function to multiple data
Dear R helpers,
I know R language at a preliminary level. This is my first post to this R
forum. I have recently learned the use of function and have been successful
in writing few on my own. However I am not able to figure out how to apply
the function to multiple sets of data.
# MY QUERY
Suppose I am having following data.frame
df = data.frame(k = c(1:8), ratings = c("A",
2015 Jul 09
5
[LLVMdev] [RFC] New StackMap format proposal (StackMap v2)
> On Jul 9, 2015, at 3:33 PM, Swaroop Sridhar <Swaroop.Sridhar at microsoft.com> wrote:
>
> Regarding Call-site size specification:
>
> CoreCLR (https://github.com/dotnet/coreclr <https://github.com/dotnet/coreclr>) requires the size of the Call-instruction to be reported in the GCInfo encoding.
>
> The runtime performs querries for StackMap records using
2003 Sep 04
1
error in lm.fit
Hello R user,
I have several data frames with >100 columns and I did a linear regression
over time of each column
df1.lm <- lapply(df1, function(x) lm(x~year)$coeff[2])
that worked fine and I get slope of each column oder time - until I divided
df1 by df2
df3 <- df1/df2
> df3.lm <- lapply(df3, function(x) lm(x~year)$coeff[2])
Error in lm.fit(x, y, offset = offset, ...) :
2015 Aug 27
2
RFC: alloca -- specify address space for allocation
Please see inline.
From: Chandler Carruth [mailto:chandlerc at google.com]
Sent: Wednesday, August 26, 2015 7:03 PM
To: Swaroop Sridhar <Swaroop.Sridhar at microsoft.com>; llvm-dev <llvm-dev at lists.llvm.org>; Philip Reames <listmail at philipreames.com>; Sanjoy Das <sanjoy at playingwithpointers.com>
Subject: Re: [llvm-dev] RFC: alloca -- specify address space for
2011 Oct 24
1
using predict.lm() within a function
I've written a simple function to draw a regression line in a plot and
annotate the line showing the slope
with a label. It works, as I'm using it, when the horizontal variable
is 'x', but gives incorrect results otherwise.
What's wrong?
# simple function to show the slope of a line
show.beta <- function(model, x="x", x1, x2, label, col="black", ...)
2010 Apr 27
3
Problem calculating multiple regressions on a data frame.
Hi there,
I am stuck trying to solve what should be a fairly easy problem.
I have a data frame that essentially consists of (ID, time as seqMonth,
variable, value) and i want to find the regression coefficient of value vs
time for each combination of ID and Variable.
I have tried several approaches and none of them seems to work as i
expected.
For example, i have tried:
2015 Aug 27
4
RFC: alloca -- specify address space for allocation
Inline.
From: Philip Reames [mailto:listmail at philipreames.com]
Sent: Thursday, August 27, 2015 11:01 AM
To: Swaroop Sridhar <Swaroop.Sridhar at microsoft.com>; llvm-dev <llvm-dev at lists.llvm.org>; Sanjoy Das <sanjoy at playingwithpointers.com>
Cc: Joseph Tremoulet <jotrem at microsoft.com>; Andy Ayers <andya at microsoft.com>; Russell Hadley <rhadley at
2015 Aug 29
5
RFC: alloca -- specify address space for allocation
> -----Original Message-----
> From: Philip Reames [mailto:listmail at philipreames.com]
> Sent: Friday, August 28, 2015 9:38 AM
> To: Swaroop Sridhar <Swaroop.Sridhar at microsoft.com>; llvm-dev <llvm-
> dev at lists.llvm.org>; Sanjoy Das <sanjoy at playingwithpointers.com>
> Cc: Joseph Tremoulet <jotrem at microsoft.com>; Andy Ayers
> <andya at
2015 Aug 27
2
RFC: alloca -- specify address space for allocation
On 08/26/2015 07:02 PM, Chandler Carruth wrote:
> On Wed, Aug 26, 2015 at 6:46 PM Swaroop Sridhar via llvm-dev
> <llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org>> wrote:
>
> Currently, the alloca instruction always allocates in the generic
> address space (0).
>
> This proposal is to extend the semantics of alloca instruction to
>