Displaying 20 results from an estimated 8000 matches similar to: "retrieve name of an object?"
2010 Nov 30
3
pca analysis: extract rotated scores?
Dear all
I'm unable to find an example of extracting the rotated scores of a
principal components analysis. I can do this easily for the un-rotated
version.
data(mtcars)
.PC <- princomp(~am+carb+cyl+disp+drat+gear+hp+mpg, cor=TRUE, data=mtcars)
unclass(loadings(.PC)) # component loadings
summary(.PC) # proportions of variance
mtcars$PC1 <- .PC$scores[,1] # extract un-rotated scores of
2013 Apr 17
2
remove higher order interaction terms
Dear all,
Consider the model below:
> x <- lm(mpg ~ cyl * disp * hp * drat, mtcars)
> summary(x)
Call:
lm(formula = mpg ~ cyl * disp * hp * drat, data = mtcars)
Residuals:
Min 1Q Median 3Q Max
-3.5725 -0.6603 0.0108 1.1017 2.6956
Coefficients:
Estimate Std. Error t value Pr(>|t|)
(Intercept) 1.070e+03 3.856e+02 2.776 0.01350 *
cyl
2011 Aug 19
2
display only the top-right half of a correlation matrix?
Dear all
Is there an easy way to display only one half (top-right or
bottom-left) of a correlation matrix?
> require(Hmisc)
> rcorr(as.matrix(mtcars[ , 1:4]))
mpg cyl disp hp
mpg 1.00 -0.85 -0.85 -0.78
cyl -0.85 1.00 0.90 0.83
disp -0.85 0.90 1.00 0.79
hp -0.78 0.83 0.79 1.00
n= 32
P
mpg cyl disp hp
mpg 0 0 0
cyl 0 0 0
disp 0 0
2011 Aug 19
1
Hmisc::rcorr on a 'data.frame'?
Dear all
?Hmisc::rcorr states that it takes as main argument "a numeric
matrix". But is it normal that it fails in such an ugly way on a data
frame? (See below.) If the function didn't attempt any conversion to a
matrix, I would have expected it to state that in the error message
that it didn't accept 'data.frame' objects in its input. Also, I
vaguely remember having used
2013 Apr 16
2
efficiently diff two data frames
Dear all,
What is the quickest and most efficient way to diff two data frames,
so as to obtain a vector of indices (or logical) for rows/columns that
differ in the two data frames? For example,
> Xe <- head(mtcars)
> Xf <- head(mtcars)
> Xf[2:4,3:5] <- 55
> all.equal(Xe, Xf)
[1] "Component 3: Mean relative difference: 0.6863118"
[2] "Component 4: Mean relative
2007 Oct 01
4
how to plot a graph with different pch
I am trying to plot a graph but the points on the graph should be
different symbols and colors. It should represent what is in the legend.
I tried using the points command but this does not work. Is there
another command in R that would allow me to use different symbols and
colors for the points?
Thank you kindly.
data(mtcars)
plot(mtcars$wt,mtcars$mpg,xlab= "Weight(lbs/1000)",
2012 Mar 15
2
Ggplot barchart drops factor levels: how to show them with zero counts?
Hello,
When plotting a barchart with ggplot it drops the levels of the factor for
which no counts are available.
For example:
library(ggplot)
mtcars$cyl<-factor(mtcars$cyl)
ggplot(mtcars[!mtcars$cyl==4,], aes(cyl))+geom_bar()
levels(mtcars[!mtcars$cyl==4,])
This shows my problem. Because no counts are available for factorlevel '4',
the label 4 dissapears from the plot. However, I
2009 Aug 16
2
bootstrapped correlation confint lower than -1 ?
Dear R users,
Does the results below make any sense? Can the the interval of the
correlation coefficient be between *-1.0185* and -0.8265 at 95%
confidence level?
Liviu
> library(boot)
> data(mtcars)
> with(mtcars, cor.test(mpg, wt, met="spearman"))
Spearman's rank correlation rho
data: mpg and wt
S = 10292, p-value = 1.488e-11
alternative hypothesis: true rho is not
2020 Apr 16
2
suggestion: "." in [lsv]apply()
I'm sure this exists elsewhere, but, as a trade-off, could you achieve
what you want with a separate helper function F(expr) that constructs
the function you want to pass to [lsv]apply()? Something that would
allow you to write:
sapply(split(mtcars, mtcars$cyl), F(summary(lm(mpg ~ wt,.))$r.squared))
Such an F() function would apply elsewhere too.
/Henrik
On Thu, Apr 16, 2020 at 9:30 AM
2009 Aug 20
4
expanding 1:12 months to Jan:Dec
Dear R users
I would like to do some spreadsheet style expansion of dates. For
example, I would need to obtain a vector of months. I approached in an
obviously wrong way:
> paste(01:12)
[1] "1" "2" "3" "4" "5" "6" "7" "8" "9" "10" "11" "12"
> as.Date(paste(01:12),
2020 Apr 16
6
suggestion: "." in [lsv]apply()
Hi,
I would like to make a suggestion for a small syntactic modification of
FUN argument in the family of functions [lsv]apply(). The idea is to
allow one-liner expressions without typing "function(item) {...}" to
surround them. The argument to the anonymous function is simply referred
as ".". Let take an example. With this new feature, the following call
2013 Apr 15
6
how to transform string to "Camel Case"?
Dear all,
Given the following vector:
> (z <- c('R project', 'hello world', 'something Else'))
[1] "R project" "hello world" "something Else"
I know how to obtain all capitals or all lower case letters:
> tolower(z)
[1] "r project" "hello world" "something else"
> toupper(z)
[1] "R
2020 Apr 16
2
suggestion: "." in [lsv]apply()
Simon,
Thanks for replying. In what follows I won't try to argue (I understood
that you find this a bad idea) but I would like to make clearer some of
your point for me (and may be for others).
Le 16/04/2020 ? 16:48, Simon Urbanek a ?crit?:
> Serguei,
>> On 17/04/2020, at 2:24 AM, Sokol Serguei <sokol at insa-toulouse.fr>
>> wrote: Hi, I would like to make a
2020 Apr 20
1
suggestion: "." in [lsv]apply()
Le 19/04/2020 ? 20:46, Gabor Grothendieck a ?crit?:
> You can get pretty close to that already using fn$ in the gsubfn package:
>> library(gsubfn) fn$sapply(split(mtcars, mtcars$cyl), x ~
>> summary(lm(mpg ~ wt, x))$r.squared)
> 4 6 8 0.5086326 0.4645102 0.4229655
Right, I thought about similar syntax but this implementation has
similar flaws pointed by Simon, i.e. it reduces
2020 Apr 17
2
suggestion: "." in [lsv]apply()
Thanks Simon,
Now, I see better your argument.
Le 16/04/2020 ? 22:48, Simon Urbanek a ?crit?:
> ... I'm not arguing against the principle, I'm arguing about your
> particular proposal as it is inconsistent and not general.
This sounds promising for me. May be in a (new?) future, R core will
come with a correct proposal for this principle?
Meanwhile, to avoid substitute(),
2016 Apr 14
0
Bug in by() function which works for some FUN argument and does not work for others
I think you are not using the best function for what your intentions are.
Try:
> by(data=mtcars, INDICES=list(as.factor(mtcars$am)), FUN=colMeans)
: 0
mpg cyl disp hp drat wt
qsec vs
17.1473684 6.9473684 290.3789474 160.2631579 3.2863158 3.7688947
18.1831579 0.3684211
am gear carb
0.0000000
2013 Jan 20
2
Lattice levelplot- remove unused levels per panel
Hi,
I am using levelplot, and would like remove from each panel (condition) its
unused x levels.
e.g.
Remove from panel vs=1 the cyl level=8.
data(mtcars)
levelplot(mpg~factor(cyl)*factor(gear)|factor(vs))
Thanks for your help,
Ronny
--
View this message in context: http://r.789695.n4.nabble.com/Lattice-levelplot-remove-unused-levels-per-panel-tp4656087.html
Sent from the R help mailing
2017 Feb 16
1
possible improvement to ?with examples
A querent on StackOverflow asked about the with() function
http://stackoverflow.com/questions/42283479/why-when-to-use-with-function#42283479
and asked about the example in ?with
library(MASS)
with(anorexia, {
anorex.1 <- glm(Postwt ~ Prewt + Treat + offset(Prewt),
family = gaussian)
summary(anorex.1)
})
which saves little or no typing
2008 Jul 02
1
exporting ftable
How can I export an ftable object in the same format that appears in R
command window?
For testing that i was using this example that is in help of this function.
## Start with a contingency table.
ftable(Titanic, row.vars = 1:3)
ftable(Titanic, row.vars = 1:2, col.vars = "Survived")
ftable(Titanic, row.vars = 2:1, col.vars = "Survived")
## Start with a data frame.
x <-
2010 Dec 06
10
R crashes when making graphs
hi,
i am running R with JGR and Deducer under Ubuntu Mint Lucid. since i updated to R 2.12 i can no longer make graphs - R just crashes.
the full error report was posted to launchpad (https://bugs.launchpad.net/ubuntu/+source/openjdk-6/+bug/675905) without any success so far.
anyone with a similar problem or helpful suggestions?
thanks!
kat