Displaying 20 results from an estimated 6000 matches similar to: "integration in R?"
2010 Jun 13
2
help with R
Hi all,
I want to solve the following equation for x with rho <- 0.5
pnorm(-x)*pnorm((rho*dnorm(x)/pnorm(x)-x)/sqrt(1-rho^2))==0.05
Is there a function in R to do this?
Thank you very much!
Hannah
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2012 Apr 07
1
Uniroot error
Dear All
I am trying to find a uniroot of a function within another function (see
example) but I am getting an error message (f()values at end points not of
opposite sign). I was wondering if you would be able to advise how redefine
my function so that I can find the solution. In short my first function
calculates the intergrale which is function of "t" , I need to find the
uniroot of
2012 Jan 27
1
Help boxplot to add mean, standard error and/or stadard deviation
Dear researchers
I wish to plot a box plot without the mean line (the black line) and plot
only the mean (red square). Futhermore, is it possible to add standard
error and/or stadard deviation?
This is an example
mytest <- c(2.1,2.6,2.7,3.2,4.1,4.3,5.2,5.1,4.8,1.8,1.4,2.5,2.7,3.1,2.6,2.8)
boxplot(mytest,lty = "solid")
means <- mean(mytest,na.rm=TRUE)
points(means, pch = 22, col
2005 Mar 09
3
problem using uniroot with integrate
Hi,
I'm trying to calculate the value of the variable, dp, below, in the
argument to the integral of dnorm(x-dp) * pnorm(x)^(m-1). This
corresponds to the estimate of the sensitivity of an observer in an
m-alternative forced choice experiment, given the probability of
a correct response, Pc, a Gaussian assumption for the noise and
no bias. The function that I wrote below gives me an error:
2005 Feb 17
1
Factor level coloring in trellis plot
Hi :)
Was just wondering whether someone could help me with
adjustments to trellis plots (parallel).
I've got two way multivariate data. I want to make
parallel plots for one of the factors, and want to color
the lines according to the other factor. The first thing I
manage, but with the other I'm lost :( Can only change the
overall color.
This is basically how far I get:
2011 Oct 16
2
How to plot CI's (llim ulim) on ecodist mgram
I would like to put confidence intervals on a mantel corellogram
they are already calculated in the pmgram object but I am unsure how I
get the x value in order to plot them?
package(ecodist)
X<-1:100
Y<-rnorm(1:100)
Z<-rnorm(1:100)
XY<-dist(data.frame(X,Y))
YX<-dist(data.frame(Y,X))
my.mgram<-mgram(XY,XZ)
plot(my.mgram)
print(my.mgram)
> print(my.mgram)
$mgram
2010 Oct 26
1
Dispersion ( Plot error bars ) help
Dear List,
I am looking to plot error bars on a line using dispersion.
I have values for the upper value and for the lower values, however i am unsure how to plot different values for the upper CI and the lower CI?
I have been using
dispersion(1:35,sim,simCI,col="red")
Where there are 35 points, and simCI relates to a vector containing the lower confidence intervals, however i want
2009 Apr 07
1
get optim results into a model object
Hello all, I have an optimization routine that is giving me good results,
but the results are not in the nice "model" format like "lm". How can I get
optim results into a model so that I can use the clever 'fitted',
'residuals', and 'summary' functions?
Using optim is the only way that I was able to make a model that
1) sums the betas to 1,
2)
2009 Jul 09
2
naming of columns in R dataframe consisting of mixed data (alphanumeric and numeric)
Hello,
I have an r function that creates the following dataframe tresults2.
Notice that column 1 does not have a column heading.
Tresults2:
[,1]
estparam 18.00000
nullval 20.00000
. . .
ciWidth 2.04622
HalfInterval 1.02311
pertinent code:
results<-cbind( estparam, nullval, t, pv_left, pv_right, pv_two_t,
estse, df, cc, tbox, llim, ulim, ciWidth,
2008 Dec 31
1
uniroot() problem
I have a strange problem with uniroot() function. Here is the result :
> uniroot(th, c(-20, 20))
$root
[1] 4.216521e-05
$f.root
[1] 16.66423
$iter
[1] 27
$estim.prec
[1] 6.103516e-05
Pls forgive for not reproducing whole code, here my question is how "f.root"
can be 16.66423? As it is finding root of a function, it must be near Zero.
Am I missing something?
--
View this message
2007 Apr 25
4
How to solve difficult equations?
This below is not solvable with uniroot to find "a":
fn=function(a){
b=(0.7/a)-a
(1/(a+b+1))-0.0025
}
uniroot(fn,c(-500,500)) gives
"Error in uniroot(fn, c(-500, 500)) : f() values at end points not of
opposite sign"
I read R-help posts and someone wrote a function:
http://finzi.psych.upenn.edu/R/Rhelp02a/archive/92407.html
but it is not very precise. Is there any
2011 Sep 11
3
(no subject)
Dear all,
Can anyone take a look at my program below?
There are two functions: f1 (lambda,z,p1) and f2(p1,cl, cu).
I fixed p1=0.15 for both functions. For any fixed value of lambda (between
0.01 and 0.99),
I solve f1(p1=0.15, lambda=lambda, z)=0 for the corresponding cl and cu
values.
Then I plug the calculated cl and cu back into the function f2.
Eventually, I want to find the lambda value
2013 Jan 30
2
Integration of mixed normal distribution
Hi,
I already found a conversation on the integration of a normal
distribution and two
suggested solutions
(https://stat.ethz.ch/pipermail/r-help/2007-January/124008.html):
1) integrate(dnorm, 0,1, mean = 0, sd = 1.2)
and
2) pnorm(1, mean = 0, sd = 1.2) - pnorm(0, mean = 0, sd = 1.2)
where the pnorm-approach is supposed to be faster and with higher precision.
I want to integrate a mixed
2007 Jan 21
5
Integration + Normal Distribution + Directory Browsing Processing Questions
Hi everyone,
I am new to R, but it's really great and helped me a lot!
But now I have 2 questions. It would be great, if someone can help me:
1. I want to integrate a normal distribution, given a median and sd.
The integrate function works great BUT the first argument has to be a
function
so I do integrate(dnorm,0,1) and it works with standard m. and sd.
But I have the m and sd given.
2011 Jan 20
1
Problems with ecodist
Dear Dr.Goslee and anyone may intrested in matrix manipulate,
I am using your ecodist to do mantel and partial mantel test, I have
locality data and shape variation data, and the two distance matrixs are
given as belowings. When I run the analysis, it is always report that the
matrix is not square, but I didn't know what's wrong with my data. Would you
please help me on this. I am quite
2011 Sep 03
3
question with uniroot function
Dear all,
I have the following problem with the uniroot function. I want to find
roots for the fucntion "Fp2" which is defined as below.
Fz <- function(z){0.8*pnorm(z)+p1*pnorm(z-u1)+(0.2-p1)*pnorm(z-u2)}
Fp <- function(t){(1-Fz(abs(qnorm(1-(t/2)))))+(Fz(-abs(qnorm(1-(t/2)))))}
Fp2 <- function(t) {Fp(t)-0.8*t/alpha}
th <- uniroot(Fp2, lower =0, upper =1,
2018 Jul 30
2
trace in uniroot() ?
In looking at rootfinding for the histoRicalg project (see gitlab.com/nashjc/histoRicalg),
I thought I would check how uniroot() solves some problems. The following short example
ff <- function(x){ exp(0.5*x) - 2 }
ff(2)
ff(1)
uniroot(ff, 0, 10)
uniroot(ff, c(0, 10), trace=1)
uniroot(ff, c(0, 10), trace=TRUE)
shows that the trace parameter, as described in the Rd file, does not seem to
be
2006 Jul 02
1
workaround for numeric problems
Dear R-people,
I have to compute
C - -(pnorm(B)*dnorm(B)*B + dnorm(B)^2)/pnorm(B)^2
This expression seems to be converging to -1 if B approaches to -Inf
(although I am unable to prove it). R has no problems until B equals
around -28 or less, where both numerator and denominator go to 0 and
you get NaN. A simple workaround I did was
C <- ifelse(B > -25,
-(pnorm(B)*dnorm(B)*B
2008 Jul 31
3
Code to calculate internal rate of return
Hi all.
I am an R newbie and trying to grasp how the simple optimization routines in
R work. Specifically, I would like some guidance on how to set up a code to
calculate the internal rate of return on an investment project
(http://en.wikipedia.org/wiki/Internal_rate_of_return).
My main problem (I think) is that I want a generic code where N (number of
periods) can be easily changed and set
2012 Apr 24
2
Some Help Needed
Dear all,
I need to do some calculation where the code used are below. I get
error message when I choose k to be large, say greater than 25.
The error message is
"Error in integrate(temp, lower = 0, upper = 1, k, x, rho, m) :
the integral is probably divergent".
Can anyone give some help on resolving this. Thanks.
Hannah
m <- 100
alpha <- 0.05
rho <- 0.1
F0