[R] 0^0 computation in R : Why it is defined 1 in R ?
Dear R helpers,
today I found something interesting in R. 0^0 gives value 1 in R. But it
is undefined in mathematics. During debugging a R code, I found it and it
effects my program severely. So my question is why it is defined 1 in R?
Is there any particular reason or its a bug in the R software?
Here is one demo:
*
ff=function(u){
return( x^0 * u)
}
x=0
zz=integrate(ff,lower=0,upper=1)$value
zz
source('~/.active-rstudio-document')
zz
[1] 0.5
*
Looking forward to hear any response.
Regards,
Ritwik Bhattacharya
Indian Statistical Institute Kolkata
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[R] Query on R plot : Unequispaced label on x-axis
Dear R users, I want to plot a one variable continuous function f(x) vs x, x=[0,1]. Say for example: f(x)= x^2. Now, using the command plot(f~x) I will get a curve where the range of x-axis is [0,1] with all equispaced label. But, I need something else, and that is: my curve will be such that 80% on x-axis the range would be [0,0.5] and the rest 20% would contain [0.5,1]. Let me draw informally here. Say, the line below is my x-axis in graph and my plotting points are like: 0 0.01 0.10.5 1 Any help or suggestion will be highly appreciable. Regards, Ritwik ISI Kolkata __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
[R] R Error : Error in vector(list, gamma(n + 1)) : vector size specified is too large
Dear R-listers,
I am giving part of my R code :
###
n=15
m=1
library(partitions)
library(gregmisc)
library(combinat)
x = t(restrictedparts(n-m,m))
l = length(x[,1])
for(u in 1:l){
A= unique(matrix( unlist(permn(x[u,])), ncol=m, byrow=TRUE ))
}
###
when I put m=1 error shows : Error in vector(list, gamma(n + 1)) :
vector size specified is too large . But it works fine with other values
of m ( n). Any suggestion will be highly accepted.
Ritwik Bhattacharya
SRF, Indian Statistical Institute Kolkata
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and provide commented, minimal, self-contained, reproducible code.
[R] R Error : Error in vector(list, gamma(n + 1)) : vector size specified is too large
Dear R-listers,
I am giving part of my R code :
###
n=15
m=1
library(partitions)
library(gregmisc)
library(combinat)
x = t(restrictedparts(n-m,m))
l = length(x[,1])
for(u in 1:l){
A= unique(matrix( unlist(permn(x[u,])), ncol=m, byrow=TRUE ))
}
###
when I put m=1 error shows : Error in vector(list, gamma(n + 1)) :
vector size specified is too large . But it works fine with other values
of m ( n). Any suggestion will be highly accepted.
Ritwik Bhattacharya
SRF, Indian Statistical Institute Kolkata
This mail is scanned by Ironport
__
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
Re: [R] R Error : DATA to MATRIX
Thanks David, your suggestion works fine.btw I have another
question..If I set (n,m) little bit large, say (n=20,m=10), R cannot
handle the large data frame generated through expand.grid.Is there
any way to increase R-memory so that I can tackle large data.frame in R
?
regards
ritwik
On Mar 23, 2012, at 2:53 AM, ritwi...@isical.ac.in wrote:
Dear Sir/Madam,
I'm getting a problem with a R-code which converts a data frame to a
matrix.
It first generate a (m^(n-m) * m) matrix A and then regenerate another
matrix B having less dimension than A which satisfy some condition.
Now I
wish to assign each row of B to a vector as individual.
My problem is when I set any choice of (n,m) except m=1 it works
fine but
setting m=1 I got the error : Error in B[i, ] : incorrect number of
dimensions.
Moreover if (n,m) is large (say, (20,8)) I got the error : Error:
cannot
allocate vector of size 3.0 Gb. I know this is due to large
dimension of
matrix A. How to solve this problem.
My code is given below:
**
n=5
m=3
R=numeric(0)
# Generate all possible m-tuple ( variables having range 0 to n )
in a (
m^(n-m) * m ) matrix
r = expand.grid(rep(list(0:(n-m)), m))
write.table(r,file=test.txt,row.names=FALSE,col.names=FALSE)
a= read.table(file=test.txt,sep=,header=FALSE)
A= data.matrix(a)
#.
# Generate matrix whose rowsum = n-m
meet.crit = apply(A, 1, function(.row) any((sum(.row)) == n-m)) #
criteron for being rowsum = n
cbind(A, meet.crit) #
Checking rowsum = n for each row
-m
B=A[meet.crit,]
At this point the default behavior of the [ function is to return a
vector rather than a matrix. You need to add drop=FALSE as an
additional argument. Read the help page for ?[.
#
Generate matrix
#.
for(i in 1:choose(n-1,m-1)){
R=B[i,]
}
***
Can you please help me how to get rid of these errors. Thanking you in
advance.
Regards
Ritwik Bhattacharya
Senior Research Fellow
SQC OR UNIT, KOLKATA
INDIAN STATISTICAL INSTITUTE
--
David Winsemius, MD
West Hartford, CT
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__
R-help@r-project.org mailing list
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
[R] R Error : DATA to MATRIX
Dear Sir/Madam,
I'm getting a problem with a R-code which converts a data frame to a matrix.
It first generate a (m^(n-m) * m) matrix A and then regenerate another
matrix B having less dimension than A which satisfy some condition. Now I
wish to assign each row of B to a vector as individual.
My problem is when I set any choice of (n,m) except m=1 it works fine but
setting m=1 I got the error : Error in B[i, ] : incorrect number of
dimensions.
Moreover if (n,m) is large (say, (20,8)) I got the error : Error: cannot
allocate vector of size 3.0 Gb. I know this is due to large dimension of
matrix A. How to solve this problem.
My code is given below:
**
n=5
m=3
R=numeric(0)
# Generate all possible m-tuple ( variables having range 0 to n ) in a (
m^(n-m) * m ) matrix
r = expand.grid(rep(list(0:(n-m)), m))
write.table(r,file=test.txt,row.names=FALSE,col.names=FALSE)
a= read.table(file=test.txt,sep=,header=FALSE)
A= data.matrix(a)
#.
# Generate matrix whose rowsum = n-m
meet.crit = apply(A, 1, function(.row) any((sum(.row)) == n-m)) #
criteron for being rowsum = n
cbind(A, meet.crit) #
Checking rowsum = n for each row
-m
B=A[meet.crit,] #
Generate matrix
#.
for(i in 1:choose(n-1,m-1)){
R=B[i,]
}
***
Can you please help me how to get rid of these errors. Thanking you in
advance.
Regards
Ritwik Bhattacharya
Senior Research Fellow
SQC OR UNIT, KOLKATA
INDIAN STATISTICAL INSTITUTE
Voice : +91 9051253944
This mail is scanned by Ironport
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R-help@r-project.org mailing list
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
[R] R code Error : Hybrid Censored Weibull Distribution
Dear Sir/madam,
I'm getting a problem with a R-code which calculate Fisher Information
Matrix for Hybrid Censored Weibull Distribution. My problem is that:
when I take weibull(scale=1,shape=2) { i.e shape1} I got my desired
result but when I take weibull(scale=1,shape=0.5) { i.e shape1} it gives
error : Error in integrate(int2, lower = 0, upper = t) : the integral is
probably divergent. I could not found any theoretical interpretation of
it. I'm sending the code :
#
f3-function(t,r){
#calculation for t1
fb1-function(t,r){
v1-numeric(0)
for(j in 1:r){
int1-function(x1){
int_1- (1/p+log(x1/lamda))^2 * j * choose(n,j) *
(pweibull(x1,shape=p,scale=lamda))^(j-1) * (1 -
pweibull(x1,shape=p,scale=lamda))^(n-j) *
dweibull(x1,shape=p,scale=lamda)
int_1
}
v1[j]-integrate(int1,lower=0,upper=t)$value
}
sum(v1)
}
#calculation for t2
fb2-function(t,r){
v2-numeric(0)
for(j in 1:r){
int2-function(x2){
int_2- (1/p+log(x2/lamda))*(-p/lamda) * j * choose(n,j) *
(pweibull(x2,shape=p,scale=lamda))^(j-1) * (1 -
pweibull(x2,shape=p,scale=lamda))^(n-j) *
dweibull(x2,shape=p,scale=lamda)
int_2
}
v2[j]-integrate(int2,lower=0,upper=t)$value
}
sum(v2)
}
#calculation for t3
fb3-function(t,r){
v3-numeric(0)
for(j in 1:r){
int3-function(x3){
int_3- (p/lamda)^2 * j * choose(n,j) *
(pweibull(x3,shape=p,scale=lamda))^(j-1) * (1 -
pweibull(x3,shape=p,scale=lamda))^(n-j) *
dweibull(x3,shape=p,scale=lamda)
int_3
}
v3[j]-integrate(int3,lower=0,upper=t)$value
}
sum(v3)
}
a-c(fb1(t,r),fb2(t,r),fb2(t,r),fb3(t,r))
A-matrix(a,nrow=2,ncol=2,byrow=TRUE)
C-solve(A)
func1-function(u1){
u11- (log(-log(1-u1)))^2
u11
}
m1-(C[1,1]/p^4)*integrate(func1,lower=0,upper=1)$value
func2-function(u2){
u22- log(-log(1-u2))
u22
}
m2- (-2)*C[1,2]*(1/(p^2 *lamda))*integrate(func2,lower=0,upper=1)$value
m3- C[2,2]/lamda^2
m-m1+m2+m3
m
}
output=f3(5,10)
##
Moreover When I consider f3,fb1,fb2,fb3 all are functions of single
variable t ,desired results come but in case of two variables the
problem arises. Here t is Real Number and r is Integer.
I'm suffering this problem since last three months. Please anyone help me
out.
Thanking you in advance.
Regards
Ritwik Bhattacharya
Senior Research Fellow
SQC OR UNIT, KOLKATA
INDIAN STATISTICAL INSTITUTE
Voice : +91 9051253944
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and provide commented, minimal, self-contained, reproducible code.
