Displaying 20 results from an estimated 10000 matches similar to: "documentation / warning when passing a vector as lower/upper bound in stats::integrate()"
2011 Nov 10
2
performance of adaptIntegrate vs. integrate
Dear list,
[cross-posting from Stack Overflow where this question has remained
unanswered for two weeks]
I'd like to perform a numerical integration in one dimension,
I = int_a^b f(x) dx
where the integrand f: x in IR -> f(x) in IR^p is vector-valued.
integrate() only allows scalar integrands, thus I would need to call
it many (p=200 typically) times, which sounds suboptimal. The
2008 Sep 20
1
lower and upper limits in integrate as vectors
Dear R useRs,
i try to integrate the following function for many values
"integrand" <- function(z)
{
return(z * z)
}
i do this with a for-loop
for(i in 2:4)
{
z <- integrate(integrand, i-1, i)$value
cat("z", z, "\n")
}
to speed up the computation for many values i tried vectors
in integrate to do this.
vec1<-1:3
vec2<-2:4
2010 Sep 09
1
scalable < > delimiters in plotmath
Dear list,
I read in ?plotmath that I can use bgroup to draw scalable delimiters
such as [ ] and ( ). The same technique fails with < > however, and I
cannot find a workaround,
grid.text(expression(bgroup("<",atop(x,y),">")))
Error in bgroup("<", atop(x, y), ">") : invalid group delimiter
Regards,
baptiste
sessionInfo()
R version
2010 Sep 09
1
scalable < > delimiters in plotmath
Dear list,
I read in ?plotmath that I can use bgroup to draw scalable delimiters
such as [ ] and ( ). The same technique fails with < > however, and I
cannot find a workaround,
grid.text(expression(bgroup("<",atop(x,y),">")))
Error in bgroup("<", atop(x, y), ">") : invalid group delimiter
Regards,
baptiste
sessionInfo()
R version
2010 Sep 21
3
bivariate vector numerical integration with infinite range
Dear list,
I'm seeking some advice regarding a particular numerical integration I
wish to perform.
The integrand f takes two real arguments x and y and returns a vector
of constant length N. The range of integration is [0, infty) for x and
[a,b] (finite) for y. Since the integrand has values in R^N I did not
find a built-in function to perform numerical quadrature, so I wrote
my own after
2009 Sep 28
2
dichromat, regexp, and grid objects
Dear list,
The dichromat package defines a dichromat function which "Collapses
red-green color distinctions to approximate the effect of the two
common forms of red-green colour blindness, protanopia and
deuteranopia."
library(dichromat)
library(grid)
colorStrip <-
function (colors = 1:3, draw = TRUE)
{
x <- seq(0, 1 - 1/length(colors), length = length(colors))
y <-
2010 Mar 10
4
write.fortran
Dear all,
I'm trying to write tabular data to a text file, these data will be
the input of a Fortran program. The format needs to be
"(i7,2x,7(e15.7,2x))". I have not been able to find a clean way of
producing this output with write.table. I searched for a
"write.fortran" function similar to read.fortran() in package utils
but I couldn't find any. Below is a small
2009 Oct 06
2
ggplot equivalent of par(xaxt)
I am playing around learning ggplot and cannot see how to suppress the x or y axis values ( equivalent of xaxt in basic graphics)
It must be obvious but I'm not seeing it.
Problem
=================================================================
timedata <- structure(list(month = structure(c(5L, 5L, 5L, 5L, 5L, 5L, 5L,
5L, 5L, 5L, 5L, 5L, 5L, 5L, 5L, 5L, 5L, 5L, 5L, 5L, 5L, 5L, 5L,
5L,
2009 Jul 03
3
Variable names in lattice XY-plot
Hi,
how can I get a more descriptive text
instead of the variable names in my XY-lattice plot,
according to the table below?
Variable text
acet = "Acetylaspartate Thalamus"
chol = "Choline Thalamus"
acetp = "Acetylaspartate parieoc"
ino = "Inositole Thalamus"
I could not find a solution.
Please have a look at my syntax.
Thanks a lot,
2009 Apr 03
3
plyr and table question
Dear all,
I'm puzzled by the following example inspired by a recent question on
R-help,
cc <- textConnection("user_id website time
20 google 0930
21 yahoo 0935
20 facebook 1000
25 facebook 1015
61 google 0940")
d <- read.table(cc, head=T) ; close(cc)
table(d$user_id) # count the
2010 Aug 11
2
help to polish plot in ggplot2
Hi,
I wanted to generate a plot which is almost like the plot generated by the
following codes.
category <- paste("Geographical Category", 1:10)
grp1 <- rnorm(10, mean=10, sd=10)
grp2 <- rnorm(10, mean=20, sd=10)
grp3 <- rnorm(10, mean=15, sd=10)
grp4 <- rnorm(10, mean=12, sd=10)
mydat <- data.frame(category,grp1,grp2,grp3,grp4)
dat.m <- melt(mydat)
p <-
2010 Sep 21
1
puzzle with integrate over infinite range
Dear list,
I'm calculating the integral of a Gaussian function from 0 to
infinity. I understand from ?integrate that it's usually better to
specify Inf explicitly as a limit rather than an arbitrary large
number, as in this case integrate() performs a trick to do the
integration better.
However, I do not understand the following, if I shift the Gauss
function by some amount the integral
2011 Mar 09
2
switch and factors
Dear list,
Reading the help page for ?switch didn't give me more than a hint at
what's going on here,
x = 5
y = 2
foo <- function(a="x"){
switch(a, "x" = x,
"y" = y)
}
foo(factor('x', levels=c('y', 'x')))
# 2
It seems that switch, when given a factor, uses the numeric codes
rather than the string
2009 Mar 25
2
"[.data.frame" and lapply
Dear all,
Trying to extract a few rows for each element of a list of
data.frames, I'm puzzled by the following behaviour,
> d <- lapply(1:4, function(i) data.frame(x=rnorm(5), y=rnorm(5)))
> str(d)
>
> lapply(d, "[", i= c(1)) # fine, this extracts the first columns
> lapply(d, "[", j= c(1, 3)) # doesn't do nothing ?!
>
> library(plyr)
2009 Mar 25
2
"[.data.frame" and lapply
Dear all,
Trying to extract a few rows for each element of a list of
data.frames, I'm puzzled by the following behaviour,
> d <- lapply(1:4, function(i) data.frame(x=rnorm(5), y=rnorm(5)))
> str(d)
>
> lapply(d, "[", i= c(1)) # fine, this extracts the first columns
> lapply(d, "[", j= c(1, 3)) # doesn't do nothing ?!
>
> library(plyr)
2009 Nov 10
3
drop unused levels in subset.data.frame
Dear list,
subset has a 'drop' argument that I had often mistaken for the one in
[.factor which removes unused levels.
Clearly it doesn't work that way, as shown below,
d <- data.frame(x = factor(letters[1:15]), y = factor(LETTERS[1:3]))
s <- subset(d, y=="A", drop=TRUE)
str(s)
'data.frame': 5 obs. of 2 variables:
$ x: Factor w/ 15 levels
2011 Apr 26
2
grid stringHeight
Dear all,
I'm puzzled by the behavior of stringHeight in the grid package.
Consider the following test,
library(grid)
test <- function(lab="dog", ...){
g1 <- textGrob(lab)
g2 <- rectGrob(height=grobHeight(g1), width=grobWidth(g1))
gg <- gTree(children=gList(g1,g2), ...)
print(c("height:", convertUnit(stringHeight(lab), "mm",
2009 May 27
3
Axis label spanning multiple plots
Hello
I need to plot 3 graphs in a single column; the top two plots have the
same title, and I would like it to be written only once, centered
horizontally and spanning the two plots. Something like
t +------------+
| |
i | |
| |
t +------------+
l +------------+
| |
e | |
| |
1 +------------+
t
2008 Dec 10
4
tapply within a data.frame: a simpler alternative?
Dear list,
I have a data.frame with x, y values and a 3-level factor "group",
say. I want to create a new column in this data.frame with the values
of y scaled to 1 by group. Perhaps the example below describes it best:
> x <- seq(0, 10, len=100)
> my.df <- data.frame(x = rep(x, 3), y=c(3*sin(x), 2*cos(x),
> cos(2*x)), # note how the y values have a different
2010 Aug 27
2
export 4D data as povray density files
Dear list,
I wish to visualise some 4D data as a kind of colour / translucent
cloud in 3D. I haven't seen such plots in R (but perhaps I missed a
feature of rgl). The easiest option I found would be to export the
data in povray's df3 (density file) format and visualise it with
povray.
The format specification baffles me a little,
http://www.povray.org/documentation/view/3.6.1/374/ ;