Displaying 20 results from an estimated 3000 matches similar to: "pnorm how to decide lower-tail true or false"
2007 Jun 06
6
p-value from GEE
Hi to all,
I found in the R-help archive how to calculate the p-value for a gee result:
http://finzi.psych.upenn.edu/R/Rhelp02a/archive/74150.html
but there are two questions (I am afraid they are basic questions ...)
1. why is the result multiplicated with 2
2. how could I decide between lower.tail =TRUE and FALSE:
example:
2006 Dec 15
2
ks.test "greater" and "less"
Hello r-group
I have a question to the ks.test.
I would expect different values for less and greater between data1 and
data2.
Does anybody could explain my point of misunderstanding the function?
data1<-c(8,12,43,70)
data2<- c(70,43,12,8)
ks.test(data1,"pnorm")
ks.test(data1,"pnorm",alternative ="less") #expected < 0.001
2009 Dec 08
4
lower.tail option in pnorm
Hi,
I would have thought that these two constructions would
produce the same result but they do not.
Resp <- rbinom(10, 1, 0.5)
Stim <- rep(0:1, 5)
mm <- model.matrix(~ Stim)
Xb <- mm %*% c(0, 1)
ifelse(Resp, log(pnorm(Xb)), log(1 - pnorm(Xb)))
pnorm(as.vector(Xb), lower.tail = Resp, log.p = TRUE)
> ifelse(Resp, log(pnorm(Xb)), log(1 - pnorm(Xb)))
[1] -0.6931472 -1.8410216
2006 Aug 09
1
decimal accuracy in pnorm( )
Dear R users
Is there any way to increase the decimal accuracy for the normal probability distribution? When one needs an accurate p-value for instance this is provided by
pnorm(10,lower.tail=F)
[1] 7.619853e-24
However, what happens when instead of a P[X<x], a more accurate P[X>=x] is the objective.
Thank you in advance for your responses.
Dimitris
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2002 Feb 13
3
pnorm, relative accuracy in the tails
Dear R people
The function below should be decreasing, convex, and tend to zero when x
tends to infinity.
curve((1-pnorm(x))/dnorm(x),from=0, to=9)
>From the plot we see that for x between 8.0 and 8.3 the function is
fluctuating.
As far as I understand, this is due to the function pnorm() not being
sufficiently accurate in the tails.
I am using pnorm() in a way that has probably not been
2006 Nov 29
4
String question
Hi to all
I would to determinate whether bits is a binary code and I would to find
out the which bit is set to 1
bits <-"00110110"
I found to detect whether there are only numbers
all.digits(bits)
but is there any function to detect whether there are only 0 and 1 in
the string
And how could I get the f.e the third "bit" from the right hand side
With regards Carmen
2004 Aug 06
3
Bug in qnorm or pnorm?
I found the following strange behavior using qnorm() and pnorm():
> x<-8.21;x-qnorm(pnorm(x))
[1] 0.0004638484
> x<-8.22;x-qnorm(pnorm(x))
[1] 0.01046385
> x<-8.23;x-qnorm(pnorm(x))
[1] 0.02046385
> x<-8.24;x-qnorm(pnorm(x))
[1] 0.03046385
> x<-8.25;x-qnorm(pnorm(x))
[1] 0.04046385
> x<-8.26;x-qnorm(pnorm(x))
[1] 0.05046385
> x<-8.27;x-qnorm(pnorm(x))
2006 Nov 08
10
axis command and excel time format
Hi to all,
I have some problems to get the times-scale to the x-axis the times are
coming from an excel sheet f. e
[1] "0:01:00" "0:02:00" "0:03:00" "0:04:00" "0:05:00" "0:06:00" "0:07:00"
[8] "0:08:00" "0:09:00" "0:10:00" "0:11:00" "0:12:00" "0:13:00"
2009 Jul 17
2
how to evaluate character vector within pnorm()
Hi,
I'm trying to evaluate a character vector within pnorm. I have a vector
with values and names
x = c(2,3)
names(x) = c("mean", "sd")
so that i tried the following
temp = paste(names(x), x, sep = "=")
#gives
#> temp
#[1] "mean=2" "sd=3"
#Problem is that both values 2 and 3 are taken as values for the mean
argument in pnorm
pnorm(0,
2010 May 13
1
results of pnorm as either NaN or Inf
I stumbled across this and I am wondering if this is unexpected behavior
or if I am missing something.
> pnorm(-1.0e+307, log.p=TRUE)
[1] -Inf
> pnorm(-1.0e+308, log.p=TRUE)
[1] NaN
Warning message:
In pnorm(q, mean, sd, lower.tail, log.p) : NaNs produced
> pnorm(-1.0e+309, log.p=TRUE)
[1] -Inf
I don't know C and am not that skilled with R, so it would be hard for me
to look into
2005 Aug 30
2
about "pnorm"
As to the function"pnorm",the default degree of freedom(df) is infinite.
I wanna know how to set the df as I want.
Help on pnorm doesn't have df setting.The only choice are:"mean, sd, lower.tail, log.p",but no df.
For instance:
sample size=6
df=6-1=5
t value=9.143
I wanna to the corresponding p value by using function "pnorm".
How can I do it?
Thanks a lot
2008 Feb 07
5
pnorm
Dear R list,
I calculated a two-sided p values according to 2*(1-pnorm(8.104474)), which gives 4.440892e-16. However, it appears to be 5.30E-16 by a colleague and 5.2974E-16 from SAS. I tried to get around with mvtnorm package but it turns out to be using pnorm for univariate case. I should have missed some earlier discussions, but for the moment is there any short answer for a higher
2008 Mar 06
3
1-pnorm values in a table
Hi,
I've read in a csv file (test.csv) which gives me the following table:
Hin1 Hin2 Hin3 Hin4 Hin5 Hin6
HAI1 9534.83 4001.74 157.16 3736.93 484.60 59.25
HAI2 13272.48 1519.88 36.35 33.64 46.68 82.11
HAI3 12587.71 5686.94 656.62 572.29 351.60 136.91
HAI4 15240.81 10031.57 426.73 275.29 561.30 302.38
HAI5 15878.32 10517.14 18.93 22.00 16.91
2010 May 05
4
P values
How do u calculated p values for a z test..
so far i ve done this
A = read.table("cw3_data.txt")
xbar = mean(A)
s = 1
n = 20
mu = 0
z.test = (xbar-mu)/(s/sqrt(n))
p.value = pnorm(abs(z.test))
error = qnorm(0.99)*s/sqrt(n)
left = xbar - error
right = xbar + error
and have got values off of it...but the values for p dont match up with
other sites that i have used to check it
2006 Nov 30
3
writing function with ,... )
Hi to all
I did not found the right hints for functions with the dot-dot-dot argument.
Is it possible to write own functions with the tree dots and if yes
what's wrong with the following example?
test <- function(x, ...)
{
print (x)
if (exists("y"))print(y)
if (exists("z"))print(z)
}
test(4,y=2)
With regards Carmen
2007 Jul 07
2
No convergence using ADAPT
I am trying calculate a probability using numerical integration. The first
program I ran spit out an answer in a very short time. The program is below:
## START PROGRAM
trial <- function(input)
{
pmvnorm(lower = c(0,0), upper = c(2, 2), mean = input, sigma = matrix(c(.1, 0,
0, .1), nrow = 2, ncol = 2, byrow = FALSE))
}
require(mvtnorm)
require(adapt)
bottomB <- -5*sqrt(.1)
topB <-
2000 Oct 20
1
bug in pnorm (PR#699)
Full_Name: James Michael Rath
Version: all (I think)
OS: doesn't matter
Submission from: (NULL) (129.116.226.162)
The code for pnorm in R was adapted from a Fortran library published in the ACM
TOMS journal. The published version had a typographical error, though, which
was
pointed out in a second article published three years after the original.
The error was that a macro/variable named
2000 Nov 07
3
infinity in integrate function in R
sorry the integration was from -Inf to 1.96
The integrate function in R is not taking Inf (infinity). How do you use
infinity in R. I was doing: integrate(dnorm,- Inf, 1.96) and I was getting
Error: NA/NaN/Inf in foreign function call (arg 2). Obviously this should
be equal to pnorm(1.96)= 0.9750021. How do you get around the infinity
problem in R?
2000 Jun 19
1
missing include in pnorm.c (PR#575)
Full_Name: Julian Faraway
Version: R-Release (June 15)
OS: Linux (redhat)
Submission from: (NULL) (141.211.66.172)
R fails to compile on the current released version. Some constants
are undefined in pnorm.c. It appears that adding
#include "nmath.h"
to pnorm.c solves this problem.
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r-devel mailing list
2003 Apr 30
1
pnorm conditional (PR#2883)
--=-YFjXKq8/D/t1qWmIzQ9D
Content-Type: text/plain
Content-Transfer-Encoding: quoted-printable
I was going over the source in src/nmath/pnorm.c and noticed a little
bug in pnorm_both (in R 1.7.0). The else-if on line 205 covers the
entire real line. Seems you want an &&, not an ||. Doesn't make a big
difference (you still get a 0 or 1 from extreme starting values) but
your log