Displaying 20 results from an estimated 2000 matches similar to: "Simple Lookup... why so slow"
2003 Aug 13
6
placing labels in polygon center ?
Dear all,
is there any function to calculate the center of a polygon mass in R?
Actually I need to find the best location within polygons to place labels.
Thanks for any hint
Jens Oehlschl?gel
--
COMPUTERBILD 15/03: Premium-e-mail-Dienste im Test\ --------...{{dropped}}
2001 Sep 06
2
Array as time series?
Dear R-helpers,
I have 4-dimensional atmospheric data (x,y,z,t), which I want to analyse
on spatio-temporal diversities.
As far as I understand there only exists the possibility to construct
time series as two-dimensional matrices (mts).
For the moment, I hold it in different objects:
1. a four-dimensional array for the spatial related analyses
2. a two-dimensional mts timeserie, which was
2010 Jul 12
6
in continuation with the earlier R puzzle
When I just run a for loop it works. But if I am going to run a for loop
every time for large vectors I might as well use C or any other language.
The reason R is powerful is becasue it can handle large vectors without each
element being manipulated? Please let me know where I am wrong.
for(i in 1:length(news1o)){
+ if(news1o[i]>s2o[i])
+ s[i]<-1
+ else
+ s[i]<--1
+ }
--
2010 Dec 22
4
vectorised recovery of strsplit value ??
Dear Guru's
My first steps with R have ground to a halt! I have a vector of sample
identifiers
> sampleIDs
[1] "D1_1" "D1_2" "D1_3" "D1_4" "D1_5" "D1_6" "D1_7" "D1_8"
[9] "D1_9" "D1_10" "D1_11" "D1_12" "F1_13" "F1_14"
2016 Aug 20
2
LLVM flags for Vectorization
Hi,
I have been analyzing the LLVM vectorizer by running some benchmarks. For
vectorization, I have used the following flags:
-O3
-ffast-math
-mavx2
Am I missing any other flags which will improve vectorizer performance?
Thanks,
Santanu Das
IIT Hyd
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2003 Dec 14
5
reverse lexicographic order
Hi all,
I have some email addresses that I would like to sort in reverse
lexicographic order so that addresses from the same domain will be
grouped together. How might that be done?
Murray
--
Dr Murray Jorgensen http://www.stats.waikato.ac.nz/Staff/maj.html
Department of Statistics, University of Waikato, Hamilton, New Zealand
Email: maj at waikato.ac.nz
2016 Apr 07
4
simple question on data frames assignment
Hi I'm not sure how to ask this, but its a very easy question to answer for
an R person.
What is an easy way to check for a column value and then assigne a new
column a value based on that old column value?
For example, Im doing
colordata <- data.frame(id = c(1,2,3,4,5), color = c("blue", "red",
"green", "blue", "orange"))
for (i in
2016 Apr 07
0
simple question on data frames assignment
ifelse is vectorised, so just use that without the loop.
colordata$response <- ifelse(colordata$color == 'blue', 1, 0)
David
On 7 April 2016 at 12:41, Michael Artz <michaeleartz at gmail.com> wrote:
> Hi I'm not sure how to ask this, but its a very easy question to answer for
> an R person.
>
> What is an easy way to check for a column value and then assigne a
2019 Feb 01
2
[RFC] Vector Predication
On Thu, Jan 31, 2019 at 4:05 PM Philip Reames via llvm-dev
<llvm-dev at lists.llvm.org> wrote:
> Do such architectures frequently have arithmetic operations on the mask registers? (i.e. can I reasonable compute a conservative length given a mask register value) If I can, then having a mask as the canonical form and re-deriving the length register from a mask for a sequence of
2016 Apr 07
2
simple question on data frames assignment
== is also vectorised, and you're better off with TRUE and FALSE
rather than 1 and 0, so I'd recommend:
colordata$response <- colordata$color == 'blue'
Hadley
On Thu, Apr 7, 2016 at 6:52 AM, David Barron <dnbarron at gmail.com> wrote:
> ifelse is vectorised, so just use that without the loop.
>
> colordata$response <- ifelse(colordata$color ==
2016 Sep 19
3
[arm, aarch64] Alignment checking in interleaved access pass
Hi,
As a follow up to Patch D23646 <https://reviews.llvm.org/D23646>, I'm
trying to figure out if there should be an alignment check and what the
correct approach is.
Some background:
For stores, the pass turns:
%i.vec = shuffle <8 x i32> %v0, <8 x i32> %v1,
<0, 4, 8, 1, 5, 9, 2, 6, 10, 3, 7, 11>
store <12 x i32> %i.vec, <12 x i32>* %ptr
2003 Apr 16
2
trying to plot function using curve
Dear People,
I hope someone can help me with this. I have a function (density) which I
am trying to plot using curve. I am calling mg.hist(3,2,1), and getting
the following errors.
Error in xy.coords(x, y, xlabel, ylabel, log) :
x and y lengths differ
In addition: There were 50 or more warnings (use warnings() to see the
first 50)
> warnings()
1: longer object length
is not a multiple of
2024 Jun 12
2
Integration of functions with a vector argument
? Tue, 11 Jun 2024 18:44:08 +0000
"Levine, Michael" <mlevins at purdue.edu> ?????:
> Let us say we have a function
>
> F <- function(x){ body of the function}
>
> Where x is, in general, a d by 1 vector with d>1. Now I want to
> integrate out some of the coordinates of x, e.g. x[1] or x[2] or both
> of them etc. I'm well aware of how to integrate
2015 Jul 01
2
[LLVMdev] C as used/implemented in practice: analysis of responses
On 1 July 2015 at 17:15, Russell Wallace <russell.wallace at gmail.com> wrote:
> I'm proposing that LLVM unilaterally replace most undefined behaviour with
> implementation-defined behaviour.
That's precisely the problem. Which behaviour?
Let's have an example:
struct Foo {
long a[95];
char b[4];
double c[2];
};
void fuzz(Foo &F) {
for (int i=0; i<100;
2010 Dec 30
2
Analysing Character Strings for subsequent frequency analysis
Hi
I'm trying to get to grips with R and establish R as a teaching medium
in my secondary school. I would like to use R to analyse text so I can
produce frequency analysis of the text for subsequent examination of
ciphers. I can produce code in VBA but I am struggling when writing in R
to examine each character. There must be a clear method using the
vectorised format of R. Furthermore,
2004 Sep 14
3
reshaping some data
Hi all,
I have a data.frame with the following colnames pattern:
x1 y11 x2 y21 y22 y23 x3 y31 y32 ...
I.e. I have an x followed by a few y's. What I would like to do is turn
this wide format into a tall format with two columns: "x", "y". The
structure is that xi needs to be associated with yij (e.g. x1 should
next to y11 and y12, x2 should be next to y21, y22, and
2017 Feb 03
2
RFC: Generic IR reductions
Yes, SVE can vectorize early exit loops by using speculative
(first-faulting) loads, which essentially give a predicate of the
lanes loaded successfully. For uncounted loops with these special
loads, the loop predicate tests can be done using a 'ptest'
instruction, checking if the last element is active.
Amara
On 3 February 2017 at 10:15, Simon Pilgrim <llvm-dev at redking.me.uk>
2015 Nov 03
1
Fwd: Rcpp sugar dpois
Hi. Here is a piece of cpp code.
It works, but I do not understand the rational for the use of
"R::dpois" to call the function dpois since in the examples I have always
found directly "dpois" or "Rcpp::dpois" that both do not work in my code.
Could anyone be so patient to explain me why should it be like that?
Thaks a lot, Enrico
#include <Rcpp.h>
using
2017 Aug 05
2
LLVM Vectorisation Bug
I have matrix multiplication and stencil code. I vectorise it through the
following command.
opt -S -O3 -force-vector-width=2048 stencil.ll -o stencil_o3.ll
in both the examples of matrix mult and stencil it vectorises fine when my
loop iterations >2048. but if i keep both iterations and vector width=2048.
it produces scalar code IR not vectorizes it.
Is it llvm bug?
Please help me.
2016 Apr 07
2
simple question on data frames assignment
Hello,
Or even simpler, without ifelse,
colordata$response <- colordata$color == 'blue' + 0
Hope this helps,
Rui Barradas
?
Citando David Barron <dnbarron at gmail.com>:
> ifelse is vectorised, so just use that without the loop.
>
> colordata$response <- ifelse(colordata$color == 'blue', 1, 0)
>
> David
>
> On 7 April 2016 at 12:41, Michael