Displaying 20 results from an estimated 1000 matches similar to: "table questions"
2010 May 11
2
question about R
Hi,
At each iteration in my program,I need to generate tree vectors,X1,X2,X3,
from exponential distribution with parameters a1,a2,a3. Can you help me
please how can I do it such that it take a little time?
thank you
khazaei
2008 Jul 29
1
tensor product of equi-spaced B-splines in the unit square
Dear all,
I need to compute tensor product of B-spline defined over equi-spaced
break-points.
I wrote my own program (it works in a 2-dimensional setting)
library(splines)
# set the break-points
Knots = seq(-1,1,length=10)
# number of splines
M = (length(Knots)-4)^2
# short cut to splineDesign function
bspline = function(x) splineDesign(Knots,x,outer.ok = T)
# bivariate tensor product of
2008 Aug 08
3
Multivariate regression with constraints
Hi all,
I am running a bivariate regression with the following:
p1=c(184,155,676,67,922,22,76,24,39)
p2=c(1845,1483,2287,367,1693,488,435,1782,745)
I1=c(1530,1505,2505,204,2285,269,1271,298,2023)
I2=c(8238,6247,6150,2748,4361,5549,2657,3533,5415)
R1=I1-p1
R2=I2-p2
x1=cbind(p1,R1)
y1=cbind(p2,R2)
fit1=lm(y1~-1+x1)
summary(fit1)
Response 2:
Coefficients:
Estimate Std. Error t value
2010 May 17
2
best polynomial approximation
Dear R-users,
I learned today that there exists an interesting topic in numerical
analysis names "best polynomial approximation" (BSA). Given a function
f the BSA of degree k, say pk, is the polynomial such that
pk=arginf sup(|f-pk|)
Although given some regularity condition of f, pk is unique, pk IS NOT
calculated with least square. A quick google tour show a rich field of
research
2008 May 29
2
Troubles plotting lrm output in Design Library
Dear R-helpers,
I'm having a problem in using plot.design in Design Library. Tho
following example code produce the error:
> n <- 1000 # define sample size
> set.seed(17) # so can reproduce the results
> age <- rnorm(n, 50, 10)
> blood.pressure <- rnorm(n, 120, 15)
> cholesterol <- rnorm(n, 200, 25)
> sex <-
2008 Jul 23
1
mle2(): logarithm of negative pdfs
Hi,
In order to use the mle2-function, one has to define the likelihood function
itself. As we know, the likelihood function is a sum of the logarithm of
probability density functions (pdf). I have implemented myself the pdfs
that I am using. My problem is, that the pdfs values are negative and I
cann't take the logarithm of them in the log-likelihood function.
So how can one take the
2009 Dec 12
1
Replace NAs in a range of data frame columns
Dear all,
I'm stuck in a seemingly trivial task that I need to perform for many
datasets. Basically, I want to replace NA with 0 in a specified range of
columns in a dataframe. I know the first and last column to be recoded
only by its name.
I can select the columns starting like this
a[match('first',names(a)): match('last',names(a))]
The question is how can replace all NA
2009 May 07
1
data transformation using gamma
Hi R-users,
I have this code to uniformise the data using gamma:
> length(dp1)
[1] 696
> dim(dp1)
[1] 58 12
> dim(ahall)
[1] 1 12
> dim(bhall)
[1] 1 12
> trans_dt <- function(dt,a,b)
+ { n1 <- ncol(dt)
+ n2 <- length(dt)
+ trans <- vector(mode='numeric', length=n2)
+ dim(trans) <- dim(dt)
+ for (i in 1:n1)
+ { dt[,i] <- as.vector(dt[,i])
2009 May 04
2
Reversing axis label order
Dear R Users,
I am executing the following command to produce a line graph:
matplot(aggregate_1986[,1], aggregate_1986[,2:3], type="l", col=2:3)
On the x-axis I have values of Latitude (in column 1) ranging from -60 to +80 (left to right on the x-axis). However, I wish to have these values shown in reverse on the x-axis, going from +80 to -60 (ie. North to South in terms of Latitude).
2008 Dec 10
4
repeated searching of no-missing values
hi all,
I have a data frame such as:
1 blue 0.3
1 NA 0.4
1 red NA
2 blue NA
2 green NA
2 blue NA
3 red 0.5
3 blue NA
3 NA 1.1
I wish to find the last non-missing value in every 3ple: ie I want a 3
by 3 data.frame such as:
1 red 0.4
2 blue NA
3 blue 1.1
I have written a little script
data = structure(list(V1 = c(1L, 1L, 1L, 2L, 2L, 2L, 3L, 3L, 3L
), V2 = structure(c(1L, NA,
2013 Jan 04
1
SpatialPolygon with the max value gets no color assigned in spplot function when using "at" parameter
Hi,
I would like to do coloring of map regions based on the region values
"weight". The approach I am taking is first to break regions into equal
intervals,
classIntervals(spdf$weight,4)$brks #4 intervals in this case
and coloring all regions within the interval with the same color
col = brewer.pal(4,"RdYlGn"))
The max "weight" is as well the boundary of the
2019 Mar 03
2
bug: sample( x, size, replace = TRUE, prob= skewed.probs) produces uniform sample
When `length( skewed.probs ) > 200' uniform samples are generated in R-devel.
R-3.5.1 behaves as expected.
`epsilon` can be a lot bigger than illustrated and still the uniform distribution is produced.
Chuck
> set.seed(123)
>
> epsilon <- 1e-10
>
> ## uniform to 200 then small
> p200 <- prop.table( rep( c(1, epsilon), c(200, 999-200)))
> ## uniform to 201
2008 Jul 22
1
How to simulate heteroscedasticity (correlation)
Hi,
I would like to generate two correlated variables.
I found that funktion for doing that:
a <- rmvnorm(n=10000,mean=c(20,20),sigma=matrix(c(5,0.8*sqrt(50),
0.8*sqrt(50),10),2,2))
(using library(mvtnorm))
Now I also want to generate two correlated variables where the error
variance vary over the variable-correlation.
And I want to plot this for showing heteroscedasticity.
Like shown
2010 May 13
1
access objects in my environment
Dear group,
Here are my objects in my environment:
> ls()
[1] "Pos100415" "Pos100416" "posA" "pose15" "pose16" "pose16t"
"position" "trade" "x"
I need to pass the object "Pos100415" to a function. This element is a
data.frame, obtained through a function: Pos(x)<-myfun(x)
2010 Sep 16
2
use same breaks and colors, but the displayed scale are different-image.plot()
Hi all,
I want to put several figures in a one figure for easy comparison, so i
need to use the same methods to plot these figures. The following is an
example. I also list my method, but it does not work.
#Example data
x<- 1:10; y<- 1:10; z<- outer( x,y,"+");z2<- outer( x,y,"-")
#Quick view them
image.plot(x,y,z) #relatively larger value
image.plot(x,y,z2)
2003 Apr 02
1
normalized frequency histogram
Hi folks
I'm trying to plot a normalized frequency histogram of some data.
After checking the docs, it seems there is no built in feature for this.
from the definition for normalized frequency, I need to divide the
relative frequency by the size of the intervals being used.
So I could divide the series by this interval length, and then plot the
relative frequency.
The problem is
2010 Nov 19
1
Color Alaska in USA map
Hello:
I have a problem when I tried to color the USA map with different colors. The following is my data (I only used the second column of data):
alaska, 1, 2
Hawaii, 0, 0
USA, 5, 5
And here is my code:
library("latticeExtra")
library("mapproj")
state<-read.table("C:\\usaclass.txt",sep=",")
state
2007 Sep 27
5
New R website: R-Cookbook.com
R Community,
I've put together a website that I thought this mailing list might be
interested in: http://www.r-cookbook.com
It's a (free) community-driven content management system for R
"recipes", or working examples. Some of the features of the site are
code highlighting, recipe ratings, recipe comments, personal "recipe
boxes" to save your favorite
2012 Oct 17
2
loop of quartile groups
Greetings R users,
My goal is to generate quartile groups of each variable in my data set. I
would like each experiment to have its designated group added as a
subsequent column. I can accomplish this individually with the following
code:
brks <- with(data_variables,
cut2(var2, g=4))
#I don't want the actual numbers, I need a numbered group
data$test1=factor(brks,
2009 Mar 19
8
function question
Dear R Gurus:
I read somewhere that functions are considered vectors.
Is this true, please?
thanks
Edna Bell