Displaying 20 results from an estimated 1000 matches similar to: "strptime format = "%H:%M:%OS6""
2012 Aug 30
3
apply --> data.frame
Is there a way for an apply-type function to return a data frame?
the closest thing I think of is
foo <- as.data.frame(sapply(...))
names(foo) <- c(....)
is there a more "elegant" way?
Thanks!
--
Sam Steingold (http://sds.podval.org/) on Ubuntu 12.04 (precise) X 11.0.11103000
http://www.childpsy.net/ http://palestinefacts.org http://dhimmi.com
http://honestreporting.com
2006 May 11
3
cannot turn some columns in a data frame into factors
Hi,
I have a data frame df and a list of names of columns that I want to
turn into factors:
df.names <- attr(df,"names")
sapply(factors, function (name) {
pos <- match(name,df.names)
if (is.na(pos)) stop(paste(name,": no such column\n"))
df[[pos]] <- factor(df[[pos]])
cat(name,"(",pos,"):",is.factor(df[[pos]]),"\n")
2011 Feb 15
1
[[]] confusion
what does the output for [[]] mean here:
> all$X.Time[5]
[1] "2011-02-15 09:32:26.37222"
> all$X.Time[[5]]
[1] 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
> all$X.Time[1]
[1] "2011-02-15 09:31:29.18761"
> all$X.Time[[1]]
[1] 29.18761 34.30949 36.38144 12.28500 26.37222 47.00837 40.20271 32.83765
[9] 54.56998 28.56961 55.96641 28.91920 32.29962 10.94081 34.31731
2012 Mar 14
2
sum(hist$density) == 2 ?!
> x <- rnorm(1000)
> h <- hist(x,plot=FALSE)
> sum(h$density)
[1] 2 ----------------------------- shouldn't it be 1?!
> h <- hist(x,plot=FALSE, breaks=(-4:4))
> sum(h$density)
[1] 1 ----------------------------- now it's 1. why?!
--
Sam Steingold (http://sds.podval.org/) on Ubuntu 11.10 (oneiric) X 11.0.11004000
http://www.childpsy.net/ http://www.memritv.org
2011 Aug 16
2
merge(join) problem
I have two datasets:
A with columns Open and Name (and many others, irrelevant to the merge)
B with columns Time and Name (and many others, irrelevant to the merge)
I want the dataset AB with all these columns
Open from A - a difftime (time of day)
Time from B - a difftime (time of day)
Name (same in A & B) - a factor, does NOT index rows, i.e., there are
_many_ rows in both A & B with
2012 Aug 27
1
matrix.csr %*% matrix --> matrix
When a sparse matrix is multiplied by a regular one, the result is
usually not sparse. However, when matrix.csr is multiplied by a regular
matrix in R, a matrix.csr is produced.
Is there a way to avoid this?
Thanks!
--
Sam Steingold (http://sds.podval.org/) on Ubuntu 12.04 (precise) X 11.0.11103000
http://www.childpsy.net/ http://palestinefacts.org http://truepeace.org
2013 Sep 18
2
strsplit with a vector split argument
Hi,
I find this behavior unexpected:
--8<---------------cut here---------------start------------->8---
> strsplit(c("a,b;c","d;e,f"),c(",",";"))
[[1]]
[1] "a" "b;c"
[[2]]
[1] "d" "e,f"
--8<---------------cut here---------------end--------------->8---
I thought that it should be identical to this:
2012 Sep 19
4
where are these NAs coming from?
I see this:
--8<---------------cut here---------------start------------->8---
> length(which(is.na(z$language)))
[1] 0
> locals <- z[z$country == mycountry,]
> length(which(is.na(locals$language)))
[1] 229
--8<---------------cut here---------------end--------------->8---
where are those locals without the language coming from?!
--
Sam Steingold (http://sds.podval.org/) on
2012 Oct 18
3
how to concatenate factor vectors?
How do I concatenate two vectors of factors?
--8<---------------cut here---------------start------------->8---
> a <- factor(5:1,levels=1:9)
> b <- factor(9:1,levels=1:9)
> str(c(a,b))
int [1:14] 5 4 3 2 1 9 8 7 6 5 ...
> str(unlist(list(a,b),use.names=FALSE))
Factor w/ 9 levels "1","2","3","4",..: 5 4 3 2 1 9 8 7 6 5 ...
2012 Jul 13
1
LiblineaR: read/write model files?
How do I read/write liblinear models to files?
E.g., if I train a model using the command line interface, I might want
to load it into R to look the histogram of the weights.
Or I might want to train a model in R and then apply it using a command
line interface.
--
Sam Steingold (http://sds.podval.org/) on Ubuntu 12.04 (precise) X 11.0.11103000
http://www.childpsy.net/
2012 Aug 27
1
write.matrix.csr data conversion
> write.matrix.csr(mx, y = y, file = file)
> table(y)
0 1
5194394 23487
$ cut -d' ' -f1 f | sort | uniq -c
23487 2
5194394 1
i.e., 0 is written as 1 and 1 is written as 2.
why?
is there a way to disable this?
--
Sam Steingold (http://sds.podval.org/) on Ubuntu 12.04 (precise) X 11.0.11103000
http://www.childpsy.net/ http://palestinefacts.org
2012 Oct 07
2
a merge() problem
I know it does not look very good - using the same column names to mean
different things in different data frames, but here you go:
--8<---------------cut here---------------start------------->8---
> x <- data.frame(a=c(1,2,3),b=c(4,5,6))
> y <- data.frame(b=c(1,2),a=c("a","b"))
>
2006 Mar 17
6
removing NA from a data frame
Hi,
It appears that deal does not support missing values (NA), so I need to
remove them (NAs) from my data frame.
how do I do this?
(I am very new to R, so a detailed step-by-step
explanation with code samples would be nice).
Some columns (variables) have quite a few NAs, so I would rather drop
the whole column than sacrifice all the rows (observations) which have
NA in that column.
How do I
2012 Sep 19
2
drop zero slots from table?
I find myself doing
--8<---------------cut here---------------start------------->8---
tab <- table(...)
tab <- tab[tab > 0]
tab <- sort(tab,decreasing=TRUE)
--8<---------------cut here---------------end--------------->8---
all the time.
I am wondering if the "drop 0" (and maybe even sort?) can be effected by
some magic argument to table() which I fail to discover
2011 Jul 11
1
plot means ?
Hi,
I need this plot:
given: x,y - numerical vectors of length N
plot xi vs mean(yj such that |xj - xi|<epsilon)
(running mean?)
alternatively, discretize X as if for histogram plotting and plot mean y
over the center of the histogram group.
is there a simple way?
thanks!
--
Sam Steingold (http://sds.podval.org/) on CentOS release 5.6 (Final) X 11.0.60900031
http://thereligionofpeace.com
2012 Sep 20
1
aggregate help
I want to count attributes of IDs:
--8<---------------cut here---------------start------------->8---
z <- data.frame(id=c(10,20,10,30,10,20),
a1=c("a","b","a","c","b","b"),
a2=c("x","y","x","z","z","y"),
2012 Dec 04
3
list to matrix?
How do I convert a list to a matrix?
--8<---------------cut here---------------start------------->8---
list(c(50000, 101), c(1e+05, 46), c(150000, 31), c(2e+05, 17),
c(250000, 19), c(3e+05, 11), c(350000, 12), c(4e+05, 25),
c(450000, 19), c(5e+05, 16))
as.matrix(a)
[,1]
[1,] Numeric,2
[2,] Numeric,2
[3,] Numeric,2
[4,] Numeric,2
[5,] Numeric,2
[6,] Numeric,2
[7,]
2011 Feb 15
1
summary for factors is not very informative
summary() for a factor prints:
ColName
SNDK : 72
VXX : 36
MWW : 30
ACI : 28
FRO : 28
(Other):1801
it would have been much more useful if it additionally
printed frequency stats as if by
summary(aggregate(frame$ColName,by=list(frame$ColName),FUN=length)$x)
--
Sam Steingold (http://sds.podval.org/) on CentOS release 5.3 (Final)
http://jihadwatch.org
2011 Feb 15
1
all.equal: subscript out of bounds
When I do
> all(all$X.Time == all$Y.Time);
[1] TRUE
as expected, but
> all.equal(all$X.Time,all$Y.Time);
Error in target[[i]] : subscript out of bounds
why?
thanks!
--
Sam Steingold (http://sds.podval.org/) on CentOS release 5.3 (Final)
http://mideasttruth.com http://honestreporting.com http://dhimmi.com
http://jihadwatch.org http://pmw.org.il http://ffii.org
The dark past once was the
2013 Sep 10
1
[PATCH] show vector length in summary()
(summary.default): show the vector length in addition to quantiles
diff -u -i -p -F '^(def' -b -w -B /home/sds/src/R-3.0.1/src/library/base/R/summary.R.old /home/sds/src/R-3.0.1/src/library/base/R/summary.R
--- /home/sds/src/R-3.0.1/src/library/base/R/summary.R.old 2013-03-05 18:02:33.000000000 -0500
+++ /home/sds/src/R-3.0.1/src/library/base/R/summary.R 2013-09-10 10:19:02.682946339