Displaying 20 results from an estimated 1000 matches similar to: "Some matrix and sandwich questions"
2004 Mar 14
1
1.8.1 Make problem on SunOS
I am trying to make R-1.8.1 on (SunOS shell1 5.8 Generic_108528-15 sun4u sparc SUNW,UltraAX-i2). I did
./configure
make
Configure output seems ok. The make proceeds until the following line appears, repeated indefinitely (until I break):
./config.status: ./confstat28489-19881/subs.frag: cannot overwrite existing file
I suspect that this may involve write permissions (and maybe
the umask set in
2006 Dec 10
1
Use of bread() function
Hello,
I am trying to extract an estimator for the bread of the sandwich
function. I used bread(fitted model) however it seems that I have missed
something as an error message "no applicable method for "bread" appears.
My fitted model is a Spatial simultaneous autoregressive error
model.(errorsarlm in spdep package)
Can anyone please tell me what I might be doing wrong?
Your
2004 Mar 08
2
getting the std errors in the lm function
Hello,
I have a simple question for you:
making:
mylm<-lm(y~x)
summary(mylm)
I get the following results:
******************************************************
Coefficients:
Estimate Std. Error t value Pr(>|t|)
(Intercept) 16.54087 0.19952 82.91 <2e-16 ***
x[1:19] -2.32337 0.04251 -54.66 <2e-16 ***
******************************************************
2010 Sep 14
1
NA confusion (length question)
Hi folks,
I am running a very simple regression using
mylm <- lm(mass ~ tarsus, na.action=na.exclude)
I would like the use the residuals from this analysis for more
regression but I'm running into a snag when I try
cbind(mylm$residuals, mydata) # where my data is the original data set
The error tells me that it cannot use cbind because the length of
mylm$residuals is
2003 Oct 11
1
Subclassing lm
I'd trying to subclass the "lm" class to produce a "mylm" class whose
instances behave like lm objects (are accepted by methods like summary.lm)
but have additional data or slots of my own design.
For starters:
setClass("mylm", "lm")
produces the somewhat cryptic:
Warning message:
Old-style (``S3'') class "mylm" supplied as a
2011 Jun 18
0
Unexpected result with lag() et diff() in plm package.
I have an unexpected result with the functions lag() and diff() in the plm
(panel data) package when used with transform(). These plm-specific
functions are supposed to generate lags and first differences within each
panel.
lag() does not work properly the first time (it reproduces the same
series--this is a common time series pitfall), BUT then it does work
properly when it is run a second
2009 Mar 31
1
using "substitute" inside a legend
Hello list,
I have a linear regression:
mylm = lm(y~x-1)
I've been reading old mail postings as well as the plotmath demo and I came
up with a way to print an equation resulting from a linear regression:
model = substitute(list("y"==slope%*%"x", R^2==rsq),
list(slope=round(mylm$coefficients[[1]],2),rsq=round(summary(mylm)$adj.r.squared,
2)))
I have four models and I
2009 May 14
1
automated polynomial regression
Dear all -
We perform some measurements with a machine that needs to be
recalibrated. The best calibration we get with polynomial regression.
The data might look like follows:
> true_y <- c(1:50)*.8
> # the real values
> m_y <- c((1:21)*1.1, 21.1, 22.2, 23.3 ,c(25:50)*.9)/0.3-5.2
> # the measured data
> x <- c(1:50)
> # and the x-axes
>
> # Now I do the following:
2011 May 20
2
extraction of mean square value from ANOVA
Hello,
I am randomly generating values and then using an ANOVA table to find the
mean square value. I would like to form a loop that extracts the mean square
value from ANOVA in each iteration. Below is an example of what I am doing.
a<-rnorm(10)
b<-factor(c(1,1,2,2,3,3,4,4,5,5))
c<-factor(c(1,2,1,2,1,2,1,2,1,2))
mylm<-lm(a~b+c)
anova(mylm)
Since I would like to use a loop to
2010 Jun 26
1
All a column to a data frame with a specific condition
Hi, folks,
Please first look at the codes:
plan_a=c('apple','orange','apple','apple','pear','bread')
plan_b=c('bread','bread','orange','bread','bread','yogurt')
value=1:6
data=data.frame(plan_a,plan_b,value)
library(plyr)
library(reshape)
mm=melt(data, id=c('plan_a','plan_b'))
2012 Mar 18
2
word frequency count
Hi:
I have a dataframe containing comma seperated group of words such as
milk,bread
bread,butter
beer,diaper
beer,diaper
milk,bread
beer,diaper
I want to output the frequency of occurrence of comma separated words
for each row and collapse duplicate rows, to make the output as shown
in the following dataframe:
milk,bread 2
bread,butter 1
beer,diaper 3
milk,bread 2
Thanks for help!
deb
2009 Jan 24
2
how to prevent duplications of data within a loop
Hi All,
I had posted a question on a similar topic, but I think it was not
focused. I am posting a modification that I think better accomplishes
this.
I hope this is ok, and I apologize if it is not. :)
I am looping through variables and running several regressions. I have
reason to believe that the data is being duplicated because I have
been
monitoring the memory use on unix.
How can I avoid
2010 Sep 01
1
transaction object - how to coerce this data
Hi,
I am wanting to look at frequent item sets using the arules package. I need
to transform my data into a "transactions" object. The data I read in from a
file has 2 columns, an ID and an item. How do I convert data like this into
a transactions object?
I've tried
class? transactions
but it only confuses me.
My data is like this....
basketID item
1 bread
1 cheese
1 milk
2
2007 Apr 06
2
lm() intercept at the end, rather than at the beginning
Hi,
I wonder if someone has already figured out a way of making
summary(mylm) # where mylm is an object of the class lm()
to print the "(Intercept)" at the last line, rather than the first
line of the output. I don't know about, say, biostatistics, but in
economics the intercept is usually the least interesting of the
parameters of a regression model. That's why, say, Stata
2005 Jun 16
1
regressing each column of a matrix on all other columns
DeaR list
I would like to predict the values of each column of a matrix A by
regressing it on all other columns of the same matrix A. I do this with
a for loop:
A <- B <- matrix(round(runif(10*3,1,10),0),10)
A
for (i in 1:length(A[1,])) B[,i] <- as.matrix(predict(lm( A[,i] ~
A[,-i] )))
B
It works fine, but I need it to be faster. I've looked at *apply but
just can't
2006 Nov 01
4
extract values from a vector
Hello,
I'm looking for a solution for the following problem:
I have two vectors
V1 <- c("apple","honey","milk","bread","butter")
V2 <- c("bread","milk")
now, I would like to know for each element in V1 if it's equal to one of
the elements in V2
I could do:
which(V1 == V2[1] | V1 == V2[2])
but what if I
2010 May 10
2
Robust SE & Heteroskedasticity-consistent estimation
Hi,
I'm using maxlik with functions specified (L, his gradient & hessian).
Now I would like determine some robust standard errors of my estimators.
So I 'm try to use vcovHC, or hccm or robcov for example
but in use one of them with my result of maxlik, I've a the following
error message :
Erreur dans terms.default(object) : no terms component
Is there some attributes
2012 Sep 23
1
ruby koans don't understand the principle sandwhich code
hello,
Im still working on ruby koans.
Now I have to do some sandwhich code.
The exercise looks like this :
require File.expand_path(File.dirname(__FILE__) + ''/edgecase'')
class AboutSandwichCode < EdgeCase::Koan
def count_lines(file_name)
file = open(file_name)
count = 0
while line = file.gets
count += 1
end
count
ensure
file.close if
2009 Nov 25
1
as.data.frame.table() to convert by() output to a data frame
Dear all,
This seems to be working, but I'd like to make sure that I'm not doing
anything wrong.
I am using by() to construct a complicated summary statistic by
several factors in my data (specifically, the 90-50 income ratio by
city and race).
cityrace.by <- by(microdata, list(microdata$city,microdata$race),
function (x) quantile(x$income, probs=0.9) / quantile(x$income,
probs=0.5)
2013 Sep 02
1
R dataframe and looping help
HI,
You may try this:
dat1<- read.table(text="
CustID TripDate Store Bread Butter Milk Eggs
1 2-Jan-12 a 2 0 2 1
1 6-Jan-12 c 0 3 3 0
1 9-Jan-12 a 3 3 0 0
1 31-Mar-13 a 3 0 0 0
2 31-Aug-12 a 0 3 3 0
2 24-Sep-12 a 3 3 0 0
2 25-Sep-12 b 3 0 0 0
",sep="",header=TRUE,stringsAsFactors=FALSE)
dat2<- dat1[,-c(1:3)]
res<- lapply(seq_len(ncol(dat2)),function(i)