Displaying 20 results from an estimated 300 matches similar to: "Help with pexp( )"
2002 May 22
2
Bug in pexp (PR#1590)
I wonder if something like this has been reported
before:
> pexp(85:86,0.438)
[1] 1 -Inf
--please do not edit the information below--
Version:
platform = i386-pc-mingw32
arch = i386
os = mingw32
system = i386, mingw32
status =
major = 1
minor = 5.0
year = 2002
month = 04
day = 29
language = R
Windows NT 4.0 (build 1381) Service Pack 6
Search Path:
.GlobalEnv,
2005 Nov 08
2
retrieve most abundant species by sample unit
Hi R-users:
[R 2.2 on OSX 10.4.3]
I have a (sparse) vegetation data frame with 500 rows (sampling
units) and 177 columns (plant species) where the data represent %
cover. I need to summarize the cover data by returning the names of
the most dominant and the second most dominant species per plot. I
reduced the data frame to omit cover below 5%; this is what it looks
like stacked. I have
2002 Feb 28
4
pexp.c (PR#1335)
Full_Name: M Welinder
Version: 1.4
OS: (src)
Submission from: (NULL) (192.5.35.38)
It seems to me that pexp can be improved in the lower_tail=TRUE and log_p=FALSE
case by using expm1. Something like
-expm1 (-x / scale);
I think.
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2010 Feb 17
1
Replicating output from a function
Hi All,
I have a function that is used with data frames having multiple id's
per row and it aggregates the data down to 1 id per row. It also
randomly selects one of the within-id values of a variable (mod),
which often differ within-id. Assume this data frame (below) is much
larger and I want to repeat this function, say 100 times, and then
derive the mean values of r over those 100
2006 Feb 03
2
Problems with ks.test
Hi everybody,
while performing ks.test for a standard exponential distribution on samples
of dimension 2500, generated everytime as new, i had this strange behaviour:
>data<-rexp(2500,0.4)
>ks.test(data,"pexp",0.4)
One-sample Kolmogorov-Smirnov test
data: data
D = 0.0147, p-value = 0.6549
alternative hypothesis: two.sided
>data<-rexp(2500,0.4)
2011 Nov 22
4
evaluation question
Dear R People:
Hope you're having a nice day.
Here is a character vector:
> yz
[1] "pexp(3.2,rate=1)"
> str(yz)
chr "pexp(3.2,rate=1)"
>
And I would like to evaluate that vector.
I tried:
> eval(as.expression(yz))
[1] "pexp(3.2,rate=1)"
>
But that doesn't work.
Any suggestions would be most welcome. I have a feeling that it's
quite
2002 May 03
6
problems with rexp ?
Does anyone know if R have any problems with the exponential random number
generation (function rexp)?
I comment it because I executed
data<-sort(rexp(100))
plot(data,dexp(data)/(1-pexp(data)),type="l")
and the graphic isn't constant.
(Note: exponential distribution have a constant hazard failure rate).
Thank you,
Juan
2006 Sep 23
1
Fitdistr() versus nls()
Hello R-Users,
I'm new to R so I apologize in advance for any big mistake I might
be doing. I'm trying to fit a set of samples with some probabilistic
curve, and I have an important question to ask; in particular I have
some data, from which I calculate manually the CDF, and then I import
them into R and try to fit: I have the x values (my original samples)
and the y values
2013 Mar 25
2
Ordering a matrix by row value in R2.15
fitz_ra wrote
> I know this is posted a lot, I've been through about 40 messages reading
> how to do this so let me apologize in advance because I can't get this
> operation to work unlike the many examples shown.
>
> I have a 2 row matrix
>> temp
> [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8]
> [,9] [,10]
> [1,] 17.000
2012 Nov 23
6
Summary statistics for matrix columns
Hi,
is there a way I can calculate a summary statistics for a columns matrix
let say we have this matrix
x <- matrix(sample(1:8000),nrow=100)
colnames(x)<- paste("Col",1:ncol(x),sep="")
if I used summary
summary(x)
i get the output for each column but I need the output to be in matrix with
rownames and all the columns beside it
this how I want it
2011 Aug 22
1
d, p, q, r - What are the math relations with each other of this functions?
Hi all,
Using the exponential distribution to exemplify: The dexp function is
the PDF (1) and pexp is the CDF (2), that is obtained integrating the
PDF. How can I get the qexp and the rexp? Considering that I have the
PDF, how this two are mathematically related to the PDF?
(1) ke^{-kx}
(2) 1-e^{kx}
Thanks in advance.
2007 May 23
2
Possible ld.exe problem when building
Dear R People:
I am trying to build R-2.5.0 from source on a Windows machinee.
I downloaded the tools and such, and started things off.
I received some odd errors messages, looked on the R Search
and found a similar problem. The suggestion was to re-load
"ld.exe".
I downloaded and installed everything again. Same problem.
I am including my output.
2006 Nov 21
1
Is there any way to know when a field is blank
I have many text files in the format below and in certain rare instances
such as below there can be nothing in one of the fields so
a double comma is written but I won't know this because I am reading in
many,many files sequentially.
# TEXT FILE
2004-02-10 00:01:31.00000,,105.60000000
2004-02-10 00:01:32.00001,,105.60000000
2004-02-10 00:01:45.00000,,105.60000000
2004-02-10
2012 Jan 27
3
generate a random number with rexp ?
dear list
I use runif to generate a ramdom number between min and max
runif(n, min=0, max=1)
however , the syntaxe of rexp does not allow that
rexp(n, rate = 1)
and it generate a number with the corresponding rate.
The question is: how to generate a number between min and max using rexp().
Regards
--
PhD candidate in Computer Science
Address
3 avenue lamine, cité ezzahra, Sousse 4000
2008 Aug 21
1
pnmath compilation failure; dylib issue?
(1) ...need to speed up a monte-carlo sampling...any suggestions about
how I can get R to use all 8 cores of a mac pro would be most useful
and very appreciated...
(2) spent the last few hours trying to get pnmath to compile under os-
x 10.5.4...
using gcc version 4.2.1 (Apple Inc. build 5553) as downloaded from
CRAN, xcode 3.0...
...xcode 3.1 installed over top of above after
2004 Dec 09
1
How can I estimate parameters of probability distributions?
Hi list,
I have a group of data. It looks like they follow a exponential
distribution. In R, how can I esimate lamda, that is the rate in pexp,
of the distribution and can I use Kolmogorov-Smirnov for hypothesis
testing in such a situation? I have read the "8.2 Examing the
distribution of a set of data" of "An Introduction to R" but I did not
find any clues on this issue.
2002 Sep 25
10
Reading complicated data file
Hi, I am new in R and I have problem with reading this data file
0 TITLE Title
0 XLEGEND Legend
-1 LABEL x
1 1 12
1 2 30
1 3 34
I want to read only lines starting with 1 (it indicates 1st plotting line)
and create data set from second and third value on this row.
Thank for advice
Jakub Zlamal
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2000 Nov 03
1
Chi-square Goodness of Fit Test
Dear R-users,
is there a function for the Chi-square Goodness of Fit Test in R
(compare function chisq.gof in S/S-PLUS).
Thanks for help.
Matthias Seitzinger
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2009 Oct 27
1
Detection Times and Poisson Distribution
Dear All,
Apologies if my questions are too basic for this list.
I am given a set of data corresponding to list of detection times (real,
non-integer numbers in general) for some events, let us say nuclear
decays to fix the ideas.
It is a small dataset, corresponding to about 400 nuclear decay times.
I would like to test the hypothesis that these decay times are
Poissonian-distributed.
What is
2013 Nov 04
2
transform one probability distribution into another
Hi guys
Given a exponential curve, is there any function on r that can generate exponential distributed random numbers?
in General I want an function that can transform one probability distribution into another??
Regards
******************************************************************
Bander
*************************************
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