Displaying 20 results from an estimated 3000 matches similar to: "Sort 1-column dataframe with rownames"
2012 May 31
3
Remove columns from dataframe based on their statistics
Hi,
I have a dataframe and want to remove columns from it
that are populated with a similar value (for the total
column) (the variation of that column is 0). Is there an
easier way than to calculate the statistics and then
remove them by hand?
A <- runif(100)
B <- rep(1,100)
C <- rep(2.42,100)
D <- runif(100)
df <- data.frame(A,B,C,D) # if want to conditionally remove column B and
2012 Mar 08
1
Save/Load function()-result to file in a loop
Hi,
I am looking for a way to save the result of a function, e.g the lm()-function to a file and reload it afterwards again. I'd like to do that in order to minimize the used memory when running the function in a loop. The actual function I want to store is the evaluate() from the dismo package.
I tried it with save() and load() but I am not sure if that is the way I should do it as I
2012 May 04
1
Generate strings from multiple variables
Hi,
it is easiest to explain what I want to do by an example:
lets assume there are two factors/variables:
A <- c(1,2,3)
B <- c(1,3,3)
Now I would like to generate a list of strings that should look like
("A1_B1","A1_B2","A2_B1","A2_B2"). So actually the string
contains all possible combinations of A and B (separated by _). This should
be also
2011 Dec 06
5
Argument validation within functions
Hi,
I just started with writing functions in R and so some questions popped up.
I provide some values as argument to my function such as:
function(a,b,c){}
Now i want that the function first checks if the arguments are valid for the function. E.g argument "a" has to be a number in the range 0-1. How can that easily done?
So far I have:
a <- as.numeric(a)
if(0 <= a &&
2011 Aug 15
2
Extracting information from lm results (multiple model runs)
Just to inform:
I posted that before in R-sig-ecology but as it might be interesting also for other useRs, I post it also to the general r-user list:
Hello Alexandre,
thank you very much. I also found another way to extract summarizing information from lm results over e.g. 1000 repeated model runs:
results2 <- t(as.data.frame(results))
summary(results2)
Although some questions popped up in
2012 Feb 03
2
Assigning objects to variable and variable to list in a for loop
Hello,
I want to use a for loop for repeadely calculating
a maxent model (package dismo, function maxent()) which
creates an object of the class maxent (S4).
I want to collect all the resulting object in a list.
I tried to simplify my for loop to explain what I want.
There are two problems/questions:
1) How can I create the new variables in the loop (using paste) and assign the objects
2) How
2012 Jun 11
2
question about changing certificate
Good day!
I'm having trouble changing certificate/keys for my dovecot(version 1.2.9).
When I set up the server (unbuntu lts 10.4.4) I did it with a self-signed certificate. I can't remember exactly what I did, just that I followed the wiki and it worked fine =)
Now I have to change the certificate because a friend bought an official one (from thawte) and I'm a bit stumped.
As dovecot
2011 Nov 15
1
grid.arrange, grid.layout - legend, global y axis title
Hello,
I created several plot with ggplot2 dev mode.
Now I want to combine the plots in a grid
e.g. 2x2 with a fixed size of the output.
What I am doing at the moment is:
grid.newpage()
pushViewport(viewport(layout = grid.layout(nrow=2, ncol=2,
widths = unit(c(7.5,6.5), "cm"),
heights = unit(rep(5, 2), "cm"))))
print(plot1, vp = viewport(layout.pos.row = 1,
2011 Aug 15
2
MCMC regress, using runif()
Hello,
just to follow up a question from last week. Here what I've done so far (here an example):
library(MCMCpack)
Y=c(15,14,23,18,19,9,19,13)
X1=c(0.2,0.6,0.45,0.27,0.6,0.14,0.1,0.52)
X2a=c(17,22,21,18,19,25,8,19)
X2b=c(22,22,29,34,19,26,17,22)
X2 <- function()runif(length(X2a), X2a, X2b)
model1 <- MCMCregress(Y~X1+X2())
summary(model1)
but I am not sure if my X2-function is
2012 Feb 14
3
Wildcard for indexing?
Hi,
I'd like to know if it is possible to use wildcards * for indexing...
E.g. I have a vector of strings. Now I'd like to select all elements
which start with A_*? I'd also need to combine that with logical operators:
"Select all elements of a vector that start with A (A*) OR that start with B (B*)"
Probably that is quite easy. I looked into grep() which I think might
2012 Jul 25
3
Installing packages "xslx" on Ubuntu (32bit)
Hi,
I just recently changed my OS to Ubuntu 12.04 (32bit). Now I tried to install some packages required by my old and working scripts. Unfortunately I fail when trying to install the package "xslx". Maybe it is related to the 32bit version of my R (its not possible to install a 64 bit version).
Can anyone help me to sucessfully install xslx?
Here some console output (e.g.
2011 Nov 24
2
dataframe indexing by number of cases per group
Hello,
assume we have following dataframe:
group <-c(rep("A",5),rep("B",6),rep("C",4))
x <- c(runif(5,1,5),runif(6,1,10),runif(4,2,15))
df <- data.frame(group,x)
Now I want to select all cases (rows) for those groups
which have more or equal 5 cases (so I want to select
all cases of group A and B).
How can I use the indexing for such questions?
df[??]...
2012 May 11
2
text(): combine expression and line break
Hi,
I would like to plot some extra text in my plot.
This should be a two line text including a special character (sigma).
I tried so far a to use expression in combination with paste and "\n"...
but I can't get the line break...
Here what I've done so far:
plot(1,type="n", xaxt='n', yaxt='n', ann=FALSE)
text(1,1,labels=expression(paste(sigma,"\n
2012 Jun 08
1
dovecot ignores entries in virtual_alias_maps when using dovecot lda
hello list,
i need help. dovecot dont look into my virtual_alias_maps .
i set via postzfixadmin an alias postmaster at domain.tld to
newmail at domainother.tld.
when i send mails to postmaster at domain.tld mails are rejected. dovecot
authworker tells
me in log: user unknown.
but i can request the data via postmap -v -q postmaster at domain.tld
mysql:/etc/postfix/mysql_virtual_alias.cf
and get
2011 Nov 03
2
variable transformation for lm
Hello,
I am doing a simple regression using lm(Y~X).
As my response and my predictor seemed to be skewed
and I can't meet the model assumptions. Therefore
I need to transform my variables.
I wanted to ask what is the preferred way to find out
if predictor and/or response needs to be transformed
and if yes how (log-transform?).
I found a procedure in "A modern approach to Regressoin
in
2012 Jun 22
6
Definition list as image caption
recently though about image captions, then i realized that this could be achiebed by Markdown Extra's definition list feature:
![alttext](http://exampl.com/img.jpg)
: here goes the *caption*
What do you think?
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2012 Jul 25
2
reshape -> reshape 2: function cast changed?
Hi,
I used to use reshape and moved to reshape2 (R 2.15.1). Now I tried some of my older scripts and was surprised that my cast function wasn't working like before.
What I did/want to do:
1) Melt a dataframe based on a vector specifying column names as measure.vars. Thats working so far:
dfm <- melt(df, measure.vars=n, variable_name = "species", na.rm = FALSE)
2) Recast the
2012 Feb 08
2
Split dataframe into new dataframes
Hi,
I want to split a dataframe based on a grouping variable (in one column). The resulting new
dataframes should be stored in a new variable. I tried to split the dataframe using split() and
to store it using a FOR loop, but thats not working so far:
df <- data.frame(A=c("A1","A1","A2","A2"),B=seq(1:4))
Fsplit <- function(x,y){
ls <-
2012 Jan 13
2
multidimensional array calculation
Hello,
probably it is quite easy but I can get it: I have
mulitple numeric vectors and a function using
all of them to calculate a new value:
L <- c(200,400,600)
AR <- c(1.5)
SO <- c(1,3,5)
T <- c(30,365)
fun <- function(L,AR,SO,T){
exp(L*AR+sqrt(SO)*log(T))
}
How can I get an array or dataframe where
all possible combinations of the factors are listed
and the new value is
2012 Apr 02
1
Unwanted page break in Rd2pdf
Hi,
I want to create a pdf of my Man-pages from my package.
Therefore I run in the terminal Rd2pdf on the package and
a pdf of all the pages is created.
After the titlepage there is the general package page, which includes
"Description" and "Details" etc. Unfortunately after the Subtitle "Details" there is a pagebreak (and 3/4 white page) which I did not set