Displaying 20 results from an estimated 12000 matches similar to: "When 1+2 != 3 (PR#9895)"
2008 Feb 18
2
Number of digits of a value for problem 7.31 RFAQ
Hello dear R users!
I did not find a function which gives information about the number of
digits of a value shown by R.
Do you know one?
I need it to solve the problem (see RFAQ 7.31)that 0.2==0.2+0.1-0.1 FALSE
The solution suggested in RFAQ is to use isTRUE(all.equal(0.2,0.2+0.1-0.1))
But if I want to compare inequality:
0.2<=0.2 +0.1-0.1 TRUE
but 0.2<=0.2 +0.1-0.1 FALSE
bad!
but in
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 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
2013 Nov 04
0
[LLVMdev] compile error when using overloaded = operator of DenseMap
On Mon, Nov 4, 2013 at 10:35 AM, Rekha R <rekharamapai at nitc.ac.in> wrote:
> Hi,
>
> I am trying to implement Available Expressions data flow analysis. I created
> the following class (I am giving here code snippet.):
>
> namespace {
> typedef DenseMap<Expression, uint32_t> DMTy; //Expression is a class I
> defined.
> struct DataFlowValue {
>
2013 Nov 04
2
[LLVMdev] compile error when using overloaded = operator of DenseMap
Hi,
I am trying to implement Available Expressions data flow analysis. I
created the following class (I am giving here code snippet.):
namespace {
typedef DenseMap<Expression, uint32_t> DMTy; //Expression is a class I
defined.
struct DataFlowValue {
DMTy ExprMap;
llvm::BitVector* DFV;
// Functions operating on the data //
bool operator==(const DataFlowValue V) const;
2011 Feb 21
1
question about solving equation using bisection method
Hi all,
I have the following two function f1 and f2.
f1 <- function(lambda,z,p1){
lambda*(p1*exp(-3*z-9/2)+(0.2-p1)*exp(4*z-8))-(1-lambda)*0.8}
f2 <- function(p1,cl, cu){
0.8*(pnorm(cl)+(1-pnorm(cu)))/(0.8*(pnorm(cl)+(1-pnorm(cu)))+p1*(pnorm(cl+3)+(1-pnorm(cu+3)))+(0.2-p1)*(pnorm(cl-4)+(1-pnorm(cu-4))))}-0.05
First fix p1 to be 0.15.
(i) choose a lambda value, say lamda=0.6,
(ii)
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,
2011 Apr 06
4
problem with all/all.equal
Hi!
In a function, I may have an instance in which all elements are equal.
> x <- rep(1,5)
>
> x
[1] 1 1 1 1 1
> identical(x)
Error in .Internal(identical(x, y, num.eq, single.NA, attrib.as.set)) :
'y' is missing
> all.equal(x)
Error in is.expression(x) : 'x' is missing
>
I don't care what particular value it is, I just want to know if they are
all
2011 Dec 23
2
missing value where TRUE/FALSE needed
Merry Xmas to all,
I am writing a function and curiously this runs sometimes on one data set
and fails on another and i cannot figure out why.
Any help much appreciated.
If i run the code below with
data <- iris[ ,1:4]
The code runs fine, but if i run on a large dataset i get the following
error (showing data structures as matrix is large)
> str(cluster.data)
num [1:9985, 1:811] 0 0 0 0
2009 Aug 28
2
[LLVMdev] A create-distinct-item function with no (other) side effects
Suppose I have some LLVM assembly like this:
declare i8* @CreateDistinctItem() nounwind
declare void @dumpBoolean(i1 %val)
define i32 @main()
{
%var1 = call i8* CreateDistinctItem()
%var2 = call i8* CreateDistinctItem()
%isEqual = icmp eq i8* %val1, %val2
call void @dumpBoolean(i1 %isEqual)
ret i32 0
}
So far so good. But if I take out the "call @dumpBoolean", the
optimizer
2008 Apr 17
1
Suggestion: add a warning in the help-file of unique()
Hello
I'm sorry if this suggestion/correction was already made but after a
search in devel list I did not find any mention of it.
I would just suggest to add a warning or an exemple for the help-file of
the function unique() like
"Note that unique() compares only identical values. Values which, are
printed equally but in facts are not identical will be treated as
different."
2018 Aug 30
4
compairing doubles
Dear all,
I a bit unsure, whether this qualifies as a bug, but it is definitly a strange behaviour. That why I wanted to discuss it.
With the following function, I want to test for evenly space numbers, starting from anywhere.
.is_continous_evenly_spaced <- function(n){
if(length(n) < 2) return(FALSE)
n <- n[order(n)]
n <- n - min(n)
step <- n[2] - n[1]
test <-
2003 Apr 24
2
R-1.7.0 build feedback: NetBSD 1.6 (PR#2837)
R-1.7.0 built on NetBSD 1.6, but the validation test suite failed:
Machinetype: Intel Pentium III (600 MHz); NetBSD 1.6 (GENERIC)
Remote gcc version: gcc (GCC) 3.2.2
Remote g++ version: g++ (GCC) 3.2.2
Configure environment: CC=gcc CXX=g++ LDFLAGS=-Wl,-rpath,/usr/local/lib
make[5]: Entering directory `/local/build/R-1.7.0/src/library'
>>> Building/Updating
2018 Aug 31
3
compairing doubles
Agreed that's it's rounding error, and all.equal would be the way to go.
I wouldn't call it a bug, it's simply part of working with floating point numbers, any language has the same issue.
And while we're at it, I think the function can be a lot shorter:
.is_continous_evenly_spaced <- function(n){
length(n)>1 && isTRUE(all.equal(n[order(n)], seq(from=min(n),
2009 Mar 16
4
Match .3 in a sequence
Hello:I am trying to match the value 0.3 in the sequence seq(.2,.3). I get
> 0.3 %in% seq(from=.2,to=.3)
[1] FALSE
Yet
> 0.3 %in% c(.2,.3)
[1] TRUE
For arbitrary sequences, this "invisible .3" has been problematic. What is
the best way to work around this?
Thank you.
Dan
[[alternative HTML version deleted]]
2007 Jun 10
3
find position
find the position of the first value who equals certain number in a vector:
Say a=c(0,0,0,0,0.2, 0.2, 0.4,0.4,0.5)
i wish to return the index value in a for which the value in the vector is
equal to 0.4 for the first time. in this case, it is 7.
[[alternative HTML version deleted]]
2018 Aug 31
2
compairing doubles
El vie., 31 ago. 2018 a las 16:00, Mark van der Loo
(<mark.vanderloo at gmail.com>) escribi?:
>
> how about
>
> is_evenly_spaced <- function(x,...) all.equal(diff(sort(x)),...)
This doesn't work, because
1. all.equal does *not* return FALSE. Use of isTRUE or identical(.,
TRUE) is required if you want a boolean.
2. all.equal compares two objects, not elements in a vector.
2012 Jan 24
5
drop columns whose rows are all 0
Hello,
I have a dataset with 40 variables, some of them are always 0 (each
row). I would like to make a subset containing only the columns which
values are not all 0, but I don't know how to do it.
I tried:
for(cut_column in 1:40) {
if(sum(dataset[,cut_column])!=0) {
columns_useful<-c(columns_useful,dataset[cut_column])
}
}
sorted_dataset<-subset(dataset,
2002 Feb 22
2
errors in integrate function?
I have been trying the integrate function in R, a function which would be
very useful for a current project of mine. But I am encountering errors
integrating the one function I have tried. The function to be integrated is
a product of a gamma demsity and a normal density:
gamma.by.normal_function(y,x,shape,scale,stdev)
return( dgamma(y,shape=shape,scale=scale)*
2018 Sep 03
2
compairing doubles
Maybe a new Operator could be defined for a fast and easy double
Comparison: `~~`
`~~` <- function (e1, e2) all.equal(e1, e2)
And document it properly.