Displaying 20 results from an estimated 30000 matches similar to: "Subset command and the : operator"
2011 Jun 20
2
Replace selected columns of a dataframe with NA
I am using the following command to replace all the missing values and
assorted typos in a dataframe with NA:
mydata[mydata>80]=NA
The problem is that the first column contains values which should be
more than 80, so really I want to do it just for
mydata[,2:length(mydata)]
I can't seem to re-write the code to fit:
mydata[,2:length(mydata)>80]=NA # no error message, but doesn't
2011 Jun 30
1
Match strings across two differently sized dataframes and copy corresponding row to dataframe
Hello-
Sorry, this is a bit of a noob question, but I can't seem to progress
it any further.
I have two dataframes which contain a series of strings which exactly
match. The problem is one has more rows than the other (more cases
have been added) and they have been sorted so that they are not in the
same order. The smaller dataframe, though, contains in another column
which has codes
2012 Jan 09
3
as.numeric() generates NAs inside an apply call, but fine outside of it
Hello-
I have rather a messy SPSS file which I have imported to R, I've dput'd
some of the columns at the end of this message. I wish to get rid of all
the labels and have numeric values using as.numeric. The funny thing is
it works like this:
as.numeric(mydata[,2]) # generates correct numbers
however, if I pass the whole dataframe at once like this:
apply(mydata, 1:2, function(x)
2010 May 27
3
wildcard operator
Hi Ruser
As so usual I'm trying to replicate some SAS code. I wold like to know
if there is a wildcard operators, as " : " in SAS, in R?
When running:
lm(y ~ x1 + x2 + x3 + x4 + x5 + x6 .... x9860, data=mydata)
I would like to be able to get around it by just writing something
like this:
lm(y ~ x1:x9860, data=mydata)
Anyone?
Sorry for no including a working example, but I
2007 Aug 26
3
subset using noncontiguous variables by name (not index)
Hi All,
I'm using the subset function to select a list of variables, some of
which are contiguous in the data frame, and others of which are not. It
works fine when I use the form:
subset(mydata,select=c(x1,x3:x5,x7) )
In reality, my list is far more complex. So I would like to store it in
a variable to substitute in for c(x1,x3:x5,x7) but cannot get it to
work. That use of the c function
2004 Dec 30
1
subsetting within a function
hi
I am trying to write a function around a glm or similar function, in which
I can pass the subsetting constraint as an argument to the function, but I
am having trouble.
the following commands (if I wanted SEX==0 to be my subset) in the global
environment work fine:
subexpr <- expression(SEX==0)
subtest <- with(mydata, eval(subexpr))
test.glm <- glm(y~x1+x2, data=mydata,
2012 Aug 01
2
sub setting a data frame with binomial responses
Hi everyone,
Let me have a dataframe named ?mydata? and created as below,
*> n=c(5,5,5,5) #number of trils
> x1=c(2,3,1,3) ) #number of successes
> x2=c(5,5,5,5) #number of successes
> x3=c(0,0,0,0) #number of successes
> x4=c(5,0,5,0) #number of successes
> mydata=data.frame(n,x1,x2,x3,x4)
> mydata*
n x1 x2 x3 x4
1 5 2 5 0 5
2 5 3 5 0 0
3 5 1 5 0 5
4 5 3 5 0
2007 Feb 13
1
Missing variable in new dataframe for prediction
Hi,
I'm using a loop to evaluate several models by taking adjacent variables from my dataframe.
When i try to get predictions for new values, i get an error message about a missing variable in my new dataframe.
Below is an example adapted from ?gam in mgcv package
library(mgcv)
set.seed(0)
n<-400
sig<-2
x0 <- runif(n, 0, 1)
x1 <- runif(n, 0, 1)
x2 <- runif(n, 0, 1)
x3 <-
2005 Jun 01
2
How to name variables in a single plot
Dear R Friends ,
I want to name my variables( more than 2 variables in a single plot) within a plot to distinct them from each other, but I cann't. How it is possible? I don't mean x and y axis using xlab or ylab. At the below , it follows some lines, only as an example that you could try please, if it is possible. I really thanks for your attention.
Amir
library(graphics)
y<-
2006 Mar 24
1
predict.glmmPQL Problem
Dear all,
for a cross-validation I have to use predict.glmmPQL() , where the
formula of
the corresponding glmmPQL call is not given explicitly, but constructed
using as.formula.
However, this does not work as expected:
x1<-rnorm(100); x2<-rbinom(100,3,0.5); y<-rpois(100,2)
mydata<-data.frame(x1,x2,y)
library(MASS)
# works as expected
model1<-glmmPQL(y~x1, ~1 | factor(x2),
2010 Sep 02
2
lower triangle of the correlation matrix with xtable
Dear all,
mydata<-data.frame(x1=c(1,4,6),x2=c(3,1,2),x3=c(2,1,3))
cor(mydata)
x1 x2 x3
x1 1.0000000 -0.5960396 0.3973597
x2 -0.5960396 1.0000000 0.5000000
x3 0.3973597 0.5000000 1.0000000
I wonder if it is possible to fill only lower triangle of this
correlation matrix? Using 'dist' doesn't seem to be useful as it doesnt
allow to convert this table
2006 Jun 30
2
Passing arguments to glm()
Hi there
I want to pass arguments (i.e. the response variable and the subset
argument) in a self-made function to glm.
Here is one way I can do this:
f.myglm <- function(y,subfact,subval) {
glm(d.mydata[,y]~d.mydata[,'x1'],family=binomial,subset=d.mydata[,subfact]==subval)
}
> str(d.mydata)
`data.frame': 15806 obs. of 3 variables:
$ y : Factor w/ 2 levels
2009 Sep 03
1
Help with GLM please!
Dear experts,
I have a few quick questions related to GLMs:
1) Suppose my response is of the type Yes/No, How can I control which
response I'm modelling?
2) How can I perform Type III tests? Is it with -> drop1(mymodel,
test="Chisq") ?
3) I have a numerical variable which I converted to an ordered factor as
shown below, but in the summary results of the logistic regression I
2011 Jun 07
1
variable selection in linear regression
Hello
With due respect, have a nice time. I would like to ask some command in R.
It is regarding variable selection in linear regression.
In R, there is one rebuild function called "step" which
selecting variables according to AIC.
let say i have data [y, x1,x2,x3,x4]
we start with y~b0
i compute the partial F test and choose the variable
with maximum partial F to enter the
2006 Feb 17
2
creating 3-way tables for mantelhaen.test
Hi R users
I have serveral binary variables (e.g., X1, X2, X3, X4, X5, X,6, and X7) and
one continuous variable (e.g., Y1).
I combined these variables using data.frame()
mydata <- data.frame(X1,X2,X3,X4,X5,X6,X7,Y1)
after that, I sorted this data.frame
rank.by.Y1<-order(mydata[,8])
sorted.mydata<-mydata[rank.by.Y1,]
after that, I replaced Y1's values with values ranging from 1
2002 Dec 13
2
How to get objects from a "formula" specification?
Hi:
I'd like to get the objects corresponding to the elements in a formula,
from a data frame. For example, suppose I would like to make a
function call, such as follows:
myfunc(formula="y ~ x1 + x2 + log(x3)" , data=mydata)
This function will get the vector objects y, x1, x2, and log(x3) from
the data frame "mydata" to form the design matrix and then perform a
2024 Mar 26
2
Printout and saved results
How can I have both printout and saved results at the same time.
The subroutine first return "out" and the printout gets printed, but not
saved.
I then run the "invisible" line. Results got saved and accessible but no
printout.
How can I have both printout and also have the results saved? Thank you!
> dstat4 <- function(data,digits=3){
+?? Mean??? <-
2010 Oct 31
1
Questions about Probit Analysis
Dear All,
I have some questions about probit regressions.
I saw a nice introduction at
http://bit.ly/bU9xL5
and I mainly have two questions.
(1) The first is almost about data manipulation. Consider the following
snippet
##################################################
mydata <- read.csv(url("http://www.ats.ucla.edu/stat/r/dae/binary.csv"))
names(mydata) <-
2009 May 12
2
SAS PROC SORT nodupkey
Hi,
I have the following data and I would like to delete douple names, it is almost similar to SAS PROC SORT nodupkey! Is there any function in R does this?
x1 <- rnorm(11,5,1)
x2 <- runif(11,0,1)
nam <-paste("A", c(1:4,4,5:9,9), sep=".")
mydata <- data.frame(x1,x2)
crownames(mydata) <- nam
Many thanks in advance,
Amor
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2005 Jan 05
1
subsetting within a function using lme
Thankyou for your help with subsetting within a function. I have now tried
to apply the same theory in the framework of an lme as follows:
fit1.lme <- eval(substitute(lme(fixed=fixed, data=dataframe,
random=random, correlation=corCAR1(form= corr), na.action=na.omit,
subset=subset),list(subset=subs)))
but I get the following error:
Error in switch(mode(object), name = , numeric = , call =