Displaying 20 results from an estimated 5000 matches similar to: "how to include integrate in a function that can be solved with uniroot?"
2010 Dec 07
3
understanding output of tapply/by cumsum
Dear R-users,
I have a dataset with categories and numbers.
I would like to compute and add cumulative numbers
to the dataset.
I do not understand the structure of by(...) or
tapply(...) output enough to handle it.
Here a small example
--------------
d<-expand.grid(a=1:5,b=1:3,c=1:2)
d$n = 10 * d$a + d$b +0.1* d$c
Sn<-by(d$n,list(d$a,d$c),cumsum)
str(Sn)
---------
List of 10
$ : num
2008 May 08
1
Reading multiple tables from file
Dear R-users,
I have output files having a variable number of tables
in the following format:
-------------
1
Pietje
I1 I2 Value
1 1 0.11
1 2 0.12
2 1 0.21
2
Jantje
I1 I2 I3 Value
1 1 1 0.111
3 3 3 0.333
...
-------------
Would there be an easy way
of turning this into (a list of) data.frames
with names Pietje, Jantje
and variables I1,I2,...Value?
(I1,I2 are string or categorical,
2007 Aug 01
2
Simple table with frequency variable
Hallo,
Im trying to find out how to tabulate frequencies
of factors when the data have a frequency variable.
e,g:
i<-rep(1:5,2)
j<-rep(1:2,5)
N<-10*i+j
table(i,j) gives a table of ones
as each combination occurs only once.
How does one get a table with the corresponding N's?
Thanks!
Gerrit.
--
Gerrit Draisma
Department of Public Health
Erasmus MC, University Medical Center
2006 Jul 29
1
uniroot
Hello,
I am struggling to find the root of a exponent
function.
"uniroot" is complaining about a values at end points
not of opposite sign?
s<- sapply(1:length(w),function(i)
+ {
+
+ +
+
+
uniroot(saeqn,lower=-5000,upper=0.01036597923,l=list(t=w[i],gp=gp))$root
+ })
Error in uniroot(saeqn, lower = -5000, upper =
0.01036597923, l = list(t = w[i], :
f() values at
2008 Jul 30
1
Unexpected line type in lattice plot key on pdf device
L.S.,
With the code below,
on the Windows screen the line types in the key show
as solid and dashed as in the graph,
and in the pdf file they show
as solid in the key and solid and dashed in the graph.
I would not expect that,
but may be I get something wrong.
Gerrit.
-------
library(lattice)
# pdf("pietje.pdf")
x<-0:10
xyplot((x^0.5)+(x^0.75)~x,type="o",lty=c(1,2),
2009 Jun 06
1
correct line types in lattice legends
Hallo R-users,
I do not understand how to specify the correct
line and symbol types in the legends of a lattice xyplot.
This is what I tried, but the line types and symbol in the
graph are not seen in the legend.
Any help is appreciated.
Thanks,
Gerrit.
library(lattice)
s<-rep(1:3,len=10)
x<- 1:10
y<- x+s+rnorm(10)
d<-data.frame(s,x,y)
xyplot(y~x, groups=s,data=d,
2005 Mar 09
3
problem using uniroot with integrate
Hi,
I'm trying to calculate the value of the variable, dp, below, in the
argument to the integral of dnorm(x-dp) * pnorm(x)^(m-1). This
corresponds to the estimate of the sensitivity of an observer in an
m-alternative forced choice experiment, given the probability of
a correct response, Pc, a Gaussian assumption for the noise and
no bias. The function that I wrote below gives me an error:
2011 Apr 03
1
How do I modify uniroot function to return .0001 if error ?
I am calling the uniroot function from inside another function using these
lines (last two lines of the function) :
d <- uniroot(k, c(.001, 250), tol=.05)
return(d$root)
The problem is that on occasion there's a problem with the values I'm
passing to uniroot. In those instances uniroot stops and sends a message
that it can't calculate the root because f.upper * f.lower is greater
2012 Nov 01
1
What does uniroot return when an error occurs
Hi,
I'm using the uniroot function, and would like to detect an error which
occurs, for instance, when the values at endpoints are not of opposite
signs. For example:
uniroot( function(x) x^2+1, lower=1, upper=2 ).
I want to say something like:
if "error in uniroot(...)" return NA else return uniroot$root
Thanks a lot!
Asaf
--
View this message in context:
2020 Oct 06
0
Solving a simple linear equation using uniroot give error object 'x' not found
On 06/10/2020 11:00 a.m., Sorkin, John wrote:
> Colleagues,
> I am trying to learn to use uniroot to solve a simple linear equation. I define the function, prove the function and a call to the function works. When I try to use uniroot to solve the equation I get an error message,
> Error in yfu n(x,10,20) : object 'x' not found.
>
> I hope someone can tell we how I can fix
2011 Apr 02
1
uniroot speed and vectorization?
curiosity---given that vector operations are so much faster than
scalar operations, would it make sense to make uniroot vectorized? if
I read the uniroot docs correctly, uniroot() calls an external C
routine which seems to be a scalar function. that must be slow. I am
thinking a vectorized version would be useful for an example such as
of <- function(x,a) ( log(x)+x+a )
uniroot( of, c(
2013 May 30
2
RFC: a "safe" uniroot() function for future R
With main R releases only happening yearly in spring, now is
good time to consider *and* discuss new features for what we
often call "R-devel" and more officially is
R Under development (unstable) (.....) -- "Unsuffered Consequences"
Here is one such example I hereby expose to public scrutiny:
A few minutes ago, I've committed the following to R-devel
(the
2012 Jun 22
4
Uniroot error message with in intergration
Dear all
I am trying to calculate the value of n using uniroot. Here is the message
I am having:
<<<
Error in uniroot(integ, lower = 0, upper = 1000, n) :
'interval' must be a vector of length 2 >>>
Please would you be able to give me an indication on why I am having this
error message.
Many thanks
EXAMPLE BELOW:
## t = statistics test from t -distribution
2011 Dec 14
1
uniroot function question
I have one equation, two unknowns, so I am trying to build the solution set
by running through possible values for one unknown, and then using uniroot
to solve for the accompanying second solution, then graphing the two
vectors.
p0 = .36
f = function(x) 0.29 * exp(5.66*(x - p0))
f.integral = integrate(f, p0, 1)
p1 = p0 + .01
i = 1
n = (1 - p0)/.01
p1.vector = rep(0,n)
p2.vector = rep(0,n)
for (i
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
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
2020 Oct 06
4
Solving a simple linear equation using uniroot give error object 'x' not found
Colleagues,
I am trying to learn to use uniroot to solve a simple linear equation. I define the function, prove the function and a call to the function works. When I try to use uniroot to solve the equation I get an error message,
Error in yfu n(x,10,20) : object 'x' not found.
I hope someone can tell we how I can fix the problem
2011 May 06
1
Uniroot - error
Hi,
I have tried to use uniroot to solve a value (value a in my function) that
gives f=0, and I repeat this process for 10000 times(stimulations). However
error occures from the 4625th stimulation - Error in uniroot(f, c(0, 2),
maxiter = 1000, tol = 0.001) :
f() values at end points not of opposite sign
I have also tried interval of (lower=min(U), upper=max(U)) and it won't work
as well.
2007 Mar 29
1
ansari.test.default: bug in call to uniroot?
A recent message on ansari.test() prompted me to play with the examples. This
doesn't work for me in R version 2.4.1
R> ansari.test(rnorm(100), rnorm(100, 0, 2), conf.int = TRUE)
Error in uniroot(ab, srange, tol = 1e-04, zq = qnorm(alpha/2, lower = FALSE)) :
object "ab" not found
It looks like there's a small typo in ccia() inside
ansari.test.default() in which
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