Re: [R] simulate from conditional distribution

2012-09-13 Thread Petr Savicky
1] if (length(x) >= n) break } stopifnot(length(x) >= n) x <- x[1:n] Hope this helps. Petr Savicky. __ 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

Re: [R] Trying to use pipes in R

2012-09-12 Thread Petr Savicky
ldn't put the result into a R > variable. > Do you have any comments on this? Hi. Try the following. writeLines(c("uno dos tres", "cuatro cinco", "seis"), "some_file.txt") out <- system("wc some_file.txt", intern=TRUE) out

Re: [R] Identifying duplicate rows?

2012-09-10 Thread Petr Savicky
uot;, data.frame(Value=c(73, 73, 76, 76, 74, 75))) dfA$dups <- duplicated(dfA$Value) | duplicated(dfA$Value, fromLast=TRUE) dfA State Value dups 1VA73 TRUE 2VA73 TRUE 3VA76 TRUE 4VA76 TRUE 5VA74 FALSE 6VA75 FALSE Hope this helps. Pe

Re: [R] choose() function returning anomalous results (zero instead of one)

2012-09-06 Thread Petr Savicky
ki.sciviews.org/doku.php?id=misc:r_accuracy for further examples and some hints. Hope this helps. Petr Savicky. __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-pro

Re: [R] efficient way to do 2-level loops

2012-09-06 Thread Petr Savicky
0 11 1213 [4,]56789 10 11 12 1314 [5,] 6 789 10 11 12 13 1415 Hope this helps. Petr Savicky. __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE

Re: [R] help on setting boundaries for generating random numbers

2012-09-01 Thread Petr Savicky
k } If you want to generate a vector and avoid a loop over its components, try something like the following n <- 500 while (1) { a <- rlnorm(2*n, 0.7, 1) a <- a[0.5 < a & a < 30] # only one & here if (length(a) >= n) break } a <- a[1:n] Hop

Re: [R] R minimal calculation error

2012-08-24 Thread Petr Savicky
also for the decimal arithmetic. Using 3 digit precision, the arithmetic mean of the three numbers 1.02, 1.01, 1.01 is 1.01. So, the sum of the differences 1.02 - 1.01 1.01 - 1.01 1.01 - 1.01 is not zero. See functions zapsmall(), all.equal(). Hope this helps. Petr Savicky. ___

Re: [R] updating elements of a vector sequentially - is there a faster way?

2012-08-24 Thread Petr Savicky
On Thu, Aug 23, 2012 at 09:49:33PM -0700, Gopi Goteti wrote: > I would like to know whether there is a faster way to do the below > operation (updating vec1). > > My objective is to update the elements of a vector (vec1), where a > particular element i is dependent on the previous one. I need to d

Re: [R] updating elements of a vector sequentially - is there a faster way?

2012-08-24 Thread Petr Savicky
On Fri, Aug 24, 2012 at 10:34:14AM +0200, Petr Savicky wrote: > On Thu, Aug 23, 2012 at 09:49:33PM -0700, Gopi Goteti wrote: > > I would like to know whether there is a faster way to do the below > > operation (updating vec1). > > > > My objective is to update the

Re: [R] updating elements of a vector sequentially - is there a faster way?

2012-08-24 Thread Petr Savicky
NA. The efficiency depends on the length of the sequencies of consecutive NA in the initial vec2. If there are many, but only short sequencies of consecutive NA, the code can be more efficient than a loop over all elements. Hope this helps. Petr Savicky. _

Re: [R] Opinion: Why I find factors convenient to use

2012-08-18 Thread Petr Savicky
whether this should be the default, i would support this. Factors are very useful and sometimes necessary, but they are hard to manipulate. As Jeff Newmiller said, it is a good strategy to prepare the data as character type and convert to a factor, when they are complete. The users should know, how

Re: [R] sum over extremely small numbers

2012-08-16 Thread Petr Savicky
and using function log1p(x). set.seed(1234567) x <- - runif(10) A <- log(sum(exp(x))) y <- x[-which.max(x)] B <- max(x) + log1p(sum(exp(y - max(x A [1] 1.771461 abs(A - B) [1] 2.220446e-16 See also http://rwiki.sciviews.org/doku.php?

Re: [R] which() function not finding certain numbers

2012-08-15 Thread Petr Savicky
This is a rounding problem. print(S[204], digits=20) [1] 2.0302487 print(2.03, digits=20) [1] 2.0298046 Use function round(, digits), for example S <- round(seq(0,4,0.01), digits=7) which(S==2.03) [1] 204 which(S==3.03) [1] 304 Hope this helps. Petr

Re: [R] Solving binary integer optimization problem

2012-08-13 Thread Petr Savicky
2<=0 > x3-2*z3<=0 > x4-1*z4<=0 > x5-4000*z5<=0 > x1 >= 200 > x2 >= 100 > x3>=100 > x4>=500 > x5>=0 > > I had tried lp function from lpsolve but not able to set objective.in for > objective function. Any hel

Re: [R] Outer product from matrix by row and a vector

2012-08-07 Thread Petr Savicky
code yields on my computer [,1] [,2] [,3] [,4] [1,]6 3.5 2.67 2.25 [2,]8 5.0 4.00 3.50 Try the following out <- a[, 1] + a[, 3] %o% (1/b) max(abs(out - result)) [1] 4.440892e-16 Hope this helps. Petr Savicky. __

Re: [R] Binary Quadratic Opt?

2012-08-02 Thread Petr Savicky
On Thu, Aug 02, 2012 at 02:27:43AM -0700, khris wrote: > > On Aug 2, 2012, at 12:39 PM, Petr Savicky [via R] wrote: > > > On Wed, Aug 01, 2012 at 04:55:30AM -0700, khris wrote: > > > Hi Petr, > > > > > > It been sometime since I wrote. But here are t

Re: [R] Efficient deterministic algorithm for Matching Weighted Graphs with bounded degree.

2012-08-02 Thread Petr Savicky
On Wed, Aug 01, 2012 at 06:19:29AM -0700, khris wrote: > Hi Petr, > > The following is different line of thought which is posted in different form, > maybe you have some wise input on it. > > "I need to find Efficient(tracktable) deterministic algorithm for Matching > Weighted Graphs with bound

Re: [R] Binary Quadratic Opt?

2012-08-02 Thread Petr Savicky
On Wed, Aug 01, 2012 at 04:55:30AM -0700, khris wrote: > Hi Petr, > > It been sometime since I wrote. But here are the latest developments. > > When I give the binary linear opt problem to lpSolve optimizer than for small > instance it gives correct answer but when size of nodes increase let's

Re: [R] protential rounding error concern

2012-07-31 Thread Petr Savicky
-308 and the smallest representable number (in limited precision) is 2^-1074 = 4.940656e-324. See http://en.wikipedia.org/wiki/Double_precision_floating-point_format for more detail. Hope this helps. Petr Savicky. __ R-help@r-project.o

Re: [R] Problem creation tensor

2012-07-30 Thread Petr Savicky
mand Z[i,,]=table(occ, data_matrix[,i]) does not stop with an error, then it does not change Z[i,,] if Z[i,,] contains the values equal to table(occ, data_matrix[,i]) already before the command is executed. This may happen, for example, if you run the command twice. Petr Savicky. __

Re: [R] Optimization help

2012-07-30 Thread Petr Savicky
t;=", times=nrow(mat)) rhs <- c(80, 65, 40) out <- lp("min", objective.in=obj, const.mat=mat, const.dir=dir, const.rhs=rhs, all.int=TRUE) out$solution [1] 55 25 40 0 Hope this helps. Petr Savicky. __ R-help@r-project.org mailing

Re: [R] A "matching problem"

2012-07-30 Thread Petr Savicky
ot;a" "b" "c" [2,] "a" "c" "b" [3,] "b" "a" "c" [4,] "b" "c" "a" [5,] "c" "a" "b" [6,] "c" "b" "a" Th

Re: [R] Problem with tensor factorization

2012-07-30 Thread Petr Savicky
on't charge any values in Z. > Is there some error? Hi. I already deleted your previous emails from my folder and you start a new thread. Can you recall, what is exactly the problem and which code you use? Without a context, the reason for the above pr

Re: [R] Nearest Neighbors

2012-07-29 Thread Petr Savicky
ighbours. These are neighbours of order 2. A general iteration finds neighbours of order n by looking for neighbours of the points found in the previous step, which are the neighours of order n-1. Hope this helps. Petr Savicky. __ R-help@r-project.org mai

Re: [R] taylor expansions with real vectors

2012-07-29 Thread Petr Savicky
ctorial(r) * sum(e1^(r:0)*e2^(0:r)) } f } getF(2, 3, 3) [1] 25.3 Hope this helps. Petr Savicky. > > Le Jul 19, 2012 ?? 8:52 AM, Petr Savicky [via R] a ??crit : > > > On Wed, Jul 18, 2012 at 06:02:27PM -0700, bilelsan wrote: > > > Leave the Taylor expansion

Re: [R] Speeding up a loop

2012-07-20 Thread Petr Savicky
On Fri, Jul 20, 2012 at 04:26:34PM +0200, Petr Savicky wrote: > On Fri, Jul 20, 2012 at 05:45:30AM -0700, wwreith wrote: > > General problem: I have 20 projects that can be invested in and I need to > > decide which combinations meet a certain set of standards. The total > >

Re: [R] Speeding up a loop

2012-07-20 Thread Petr Savicky
eated using expand.grid() faster than using a for loop. Try the following g <- as.matrix(expand.grid(rep(list(0:1), times=20))) s <- rowSums(g) x <- g[s > 5 & s < 13, ] nrow(x) [1] 96 Hope this helps. Petr Savicky. __ R

Re: [R] Generating Random Numbers

2012-07-19 Thread Petr Savicky
1) { x <- 10 + 250*diff(c(0, sort(runif(4)), 1)) if (all(x <= 100)) break } x [1] 99.32985 77.04346 65.49482 33.98516 24.14672 sum(x) [1] 300 According to some tests, the average number of repetitions of the while loop is about 5. Hope t

Re: [R] finding the values to minimize sum of functions

2012-07-19 Thread Petr Savicky
le x^2 + 2y^2 + 3(c - x - y)^2 with no constraint. Hope this helps. Petr Savicky. __ 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 pro

Re: [R] Generating Random Numbers

2012-07-19 Thread Petr Savicky
s + 10) out [1] 70.63310 60.11320 67.40902 53.73936 48.10532 sum(out) [1] 300 Hope this helps. Petr Savicky. __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-proj

Re: [R] Simple tree

2012-07-19 Thread Petr Savicky
tart node and w_n the value of an end-node. Petr Savicky. __ 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] taylor expansions with real vectors

2012-07-18 Thread Petr Savicky
r-1) + e2^r) If this is correct, then try f <- 0 for (r in 1:k) { f <- f + 1/factorial(r) * sum(e1^(r:0)*e2^(0:r)) } Hope this helps. Petr Savicky. __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE

Re: [R] Problem creation tensor

2012-07-18 Thread Petr Savicky
On Wed, Jul 18, 2012 at 11:38:59AM +0200, Petr Savicky wrote: > On Tue, Jul 17, 2012 at 12:31:38PM +0200, Peppe Ricci wrote: > > Hi guys, > > > > I need some help to analyzing my data. > > I start to describe my data: I have 21 matrices, every matrix on the > >

Re: [R] Problem creation tensor

2012-07-18 Thread Petr Savicky
ble preferences. Changing UserItem <- rbind(M1, M2, ..., M21) to UserItem <- data.frame(rbind(M1, M2, ..., M21)) can resolve the problem, since then the columns will be coerced to factors, whose list of levels is complete, even if some level is not use

Re: [R] extracting rows and columns from a big matrix

2012-07-16 Thread Petr Savicky
then a possible cause can be that the text file contains the names in a form, which you do not expect. There may be a difference in case of the letters (names are case sensitive) or there may be white space in the names. Look at these names, they may be extracted using

Re: [R] How to find frequent sequences.

2012-07-14 Thread Petr Savicky
On Fri, Jul 13, 2012 at 02:38:57PM -0500, Vineet Shukla wrote: > Hi Petr, >Yes, that's really very helpful. > > > Petr : Using this interpretation, AB occurs at lines 1,3,4 and not 1,3,5. > Is this correct? > Vineet : Yes , thats right sorry for the typo. > > > > Petr: If some sequence con

Re: [R] How to find frequent sequences.

2012-07-13 Thread Petr Savicky
tterns singleSeq <- function(x, lpattern) { unique(embed(rev(x), lpattern)) } lst1 <- lapply(lst, singleSeq, lpattern=2) # combine the matrices to a single matrix mat <- do.call(rbind, lst1) # convert the patters to strings pat <- do.call(paste, c(data.frame(

Re: [R] How to get all list item to one string variable

2012-07-12 Thread Petr Savicky
quot;, "def", "ghi") paste(a, collapse=" ") [1] "abc def ghi" Hope this helps. Petr Savicky. __ 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] number of decimal places in a number?

2012-07-09 Thread Petr Savicky
The difference is not specific to R, but to the standard computer arithmetic implemented in the hardware, which uses 53 bits. Hope this helps. Petr Savicky. P.S. If you want to make further comments, please, open a new thread. __ R-help@r-project.org ma

Re: [R] number of decimal places in a number?

2012-07-08 Thread Petr Savicky
getDigits(3.123456) [1] 6 Hope this helps. Petr Savicky. __ 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] number of decimal places in a number?

2012-07-08 Thread Petr Savicky
On Sun, Jul 08, 2012 at 11:39:22AM -0700, arun wrote: > Hi Petr, > > I think sprintf and formatC are identical as it can round >22 decimal places > as opposed to print and signif > print(pi,digits=35) Hi Arun: Thank you for pointing this out. Funtion formatC() is easier to use and uses the same

Re: [R] number of decimal places in a number?

2012-07-08 Thread Petr Savicky
The same output as from print(, digits=17) may be obtained using sprintf("%20.17f", x) Of course, if the required number of digits is close to 17 or even more, the last digits are the last digits of the represented number, not of the intended result of the computation. Hope this helps.

Re: [R] Binary Quadratic Opt?

2012-07-04 Thread Petr Savicky
On Mon, Jul 02, 2012 at 06:11:37AM -0700, khris wrote: > Hi, Petr, > > > > > Hi Khris: > > > > If i understand the problem correctly, you have a list of (x,y) > > coordinates, where > > some sensor is located, but you do not know, which sensor is there. The > > database > > contains data fo

Re: [R] Binary Quadratic Opt?

2012-06-28 Thread Petr Savicky
On Tue, Jun 26, 2012 at 11:52:15PM -0700, khris wrote: > Hi Petr, > > Appreciate your feedback and sorry for the delay in responding. The > following is the description of problem from start:- > > We have a set of sensors in XY plane arranged in more or less a rectangular > grid and we know thei

Re: [R] a problem of approach

2012-06-27 Thread Petr Savicky
of this length, which has TRUE for the numbers present in the set and FALSE for the other. Removing a number means to set its bit from TRUE to FALSE, which is a very simple operation. # prepare an example numbers <- c(2, 3, 6, 8, 12, 17) x <- rep

Re: [R] do.call or something instead of for

2012-06-25 Thread Petr Savicky
tt-1] + W[, tt] } The code uses tt instead of t to avoid confusion with the transpose function. If n is always at least 2, then seq.int(from=2, length=n-1) may be replaced by 2:n. Hope this helps. Petr Savicky. __ R-help@r-project.org mailing

Re: [R] Help with a repeating process

2012-06-24 Thread Petr Savicky
from 1+i:252+i, which is equivalent to 1 + (i:252) + i. i <- 10 identical(1+i:252+i, 1 + (i:252) + i) [1] TRUE Hope this helps. Petr Savicky. __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read

Re: [R] uncoerce.... to get real number instead of integer?

2012-06-24 Thread Petr Savicky
its of the number, use one of the following. print(x, digits=17) [1] 123456789.0378 options(digits=17) x [1] 123456789.0378 The default setting of options("digits") is 7. Hope this helps. Petr Savicky. __ R-help@r-project.org mail

Re: [R] Binary Quadratic Opt?

2012-06-21 Thread Petr Savicky
On Thu, Jun 21, 2012 at 02:46:10AM -0700, khris wrote: > Hi Petr, > > Thanks for the reply. Your reply answers the question perfect. > Unfortunately converting the problem to linear opt would increase the number > of variable making it non solvable. I guess a general approach will be > unfeasible

Re: [R] ranking a vector in R

2012-06-20 Thread Petr Savicky
lo: Try x <- c(3, 2, 4, 1) rank(-x) [1] 2 3 1 4 Hope this helps. Petr Savicky. __ 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

Re: [R] Inconsistency using seq

2012-06-18 Thread Petr Savicky
mber to 0.3. print(x[4], digits=20) [1] 0.2999889 print(0.3, digits=20) [1] 0.2999889 See also http://rwiki.sciviews.org/doku.php?id=misc:r_accuracy for some more hints related to this. Petr Savicky. __ R-help@r-project.

Re: [R] (1-1e-100)==1 true?

2012-06-18 Thread Petr Savicky
e me something other than INF, but that > does not work since R would recognize x==1 in this case and therefore, > 1-x==0, so qnorm(1-x, lower.tail=F) will give me INF which is what I try to > avoid in my code. Function qnorm(x) satisfies the identity qnorm(x) = - qnorm(

Re: [R] how to delete a matrix column

2012-06-17 Thread Petr Savicky
15 16 17 18 19 20 3 4 5 [26] 6 7 8 9 10 11 12 13 14 15 1 2 3 4 5 Hope this helps. Petr Savicky. __ 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

Re: [R] A basic design question for R

2012-06-16 Thread Petr Savicky
   70 ...  F      65 ...  M      70 ... where ... represent six numbers in each row, which form a matrix x1 y1 x2 y2 x3 y3 However, i think, a list of matrices is more flexible. Petr Savicky. __ R-help@r-project.org mailing list htt

Re: [R] Binary Quadratic Opt?

2012-06-15 Thread Petr Savicky
e the number of variables significantly, so it is not guaranteed that the problem is solvable. However, it can be. Hope this helps. Petr Savicky. __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the pos

Re: [R] moving from loops to apply

2012-06-15 Thread Petr Savicky
On Fri, Jun 15, 2012 at 02:08:13PM +0200, Petr Savicky wrote: > On Fri, Jun 15, 2012 at 11:27:44AM +, Schumacher, G. wrote: > > Dear subscribers, > > > > I have made a simulation using loops rather than apply, simply because the > > loop function seems more

Re: [R] moving from loops to apply

2012-06-15 Thread Petr Savicky
atrix(x, nrow=nrow(x), ncol=length(y)) ym <- matrix(y, nrow=nrow(x), ncol=length(y), byrow=TRUE) dst2 <- -abs(xm - ym) identical(distances, dst2) [1] TRUE Apply uses a loop internally, so it need not significantly improve efficiency. Petr Savicky. _

Re: [R] matrix manipulation

2012-06-14 Thread Petr Savicky
lt;- a %*% t(a) diag(w) <- 0 w [,1] [,2] [,3] [1,]021 [2,]201 [3,]110 trans <- c(1, 10, 12) w[, ] <- trans[w + 1] w [,1] [,2] [,3] [1,]1 12 10 [2,] 121 10 [3,] 1

Re: [R] matrix manipulation

2012-06-14 Thread Petr Savicky
1121 [2,]1122 [3,]1012 The entries of w are the weights except of the diagonal, which is all ones, since each row of A contributes to the same row of B with weight one. Is this, what you are looking for? Petr Savicky. __

Re: [R] Lowest number in a numeric string

2012-06-14 Thread Petr Savicky
e(x) for (i in 1:(10^dig - 1)) { if (! i %in% x) { print(i) break } } [1] 355 The result seems to be correct. The numbers 351, 352, 353, 354 do occur in the sequence. 351 is in "135 136", 352 in "235 236", 353 in "335 336", 35

Re: [R] Lowest number in a numeric string

2012-06-14 Thread Petr Savicky
missing number is at most choose(n+1, 2) + 1. Due to this, we can consider only sequencies of digits of length at most ceiling(log10(choose(n+1, 2) + 1)). Hope this helps. Petr Savicky. __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/l

Re: [R] finding duplicates in a data frame

2012-06-13 Thread Petr Savicky
# some data base <- data.frame(x1=letters[1:5], x2=seq(1, 2, length=5), x3=seq(1.2, 1.8, length=5)) observed <- data.frame(x1=letters[6:8], x2=c(1.4, 1.01, 1.27), x3=c(1.6, 1.21, 1.37)) # choose tolerance eps <- 0.05 # inspect data mat1 <- as.matrix(base[, 2:3]) mat2 <-

Re: [R] How to subset a matrix?

2012-06-12 Thread Petr Savicky
K] and it didn't work as expected... Hi. Try the following. A <- matrix(1:16, nrow=4, ncol=4) B <- matrix(FALSE, nrow=4, ncol=4) B[2:3, 2:3] <- TRUE A[rowSums(B) != 0, colSums(B) != 0] [,1] [,2] [1,]6 10 [2,]7 11 Hope this helps. Petr Savicky. __

Re: [R] problem with sub()

2012-06-10 Thread Petr Savicky
The problem is that "21000 km" does not contain a space, but a no-break space. This may be checked by charToRaw("21000 km") # copied from your email [1] 32 31 30 30 30 c2 a0 6b 6d charToRaw("21000 km") # after rewriting the

Re: [R] table function in a matrix

2012-06-07 Thread Petr Savicky
1] 2 2 0 0 > [,2] 1 0 2 1 > [,3] 2 0 1 1 > [,4] 1 0 2 1 Hi. Try the following. a<-c("A", "A", "B", "B", "C", "A", "C", "D", "A", "D", "C", "A", "D"

Re: [R] Convert 2-dim array to 3-dim array

2012-06-04 Thread Petr Savicky
times 3 or if it is 12 times 300. In the former case, the row number 1:1200 will be translated to the values of the first two indices. In the latter case, the column number 1:300 will be translated to the last two indices. Hope this helps. Petr Savicky. _

Re: [R] Add a dim to an array

2012-06-02 Thread Petr Savicky
B1", "B2"), D = c("D1", "D2")) a2 <- array(a1, c(2, 2, 2, 1)) dimnames(a2) <- c(dimnames(a1), list(group = "low")) a2 , , D = D1, group = low B AB1 B2 A1 1 3 A2 2 4 , , D = D2, group = low

Re: [R] Quadrat counting with spatstat

2012-05-31 Thread Petr Savicky
eated in a grid 2 times 2, we get a partition of a larger square into 20 equal regions. I did not check, whether they contain the required points, since i do not know their exact coordinates, but they could. Hope this helps. Petr Savicky. __ R-help@r-project

Re: [R] Filling NA with cumprod?

2012-05-24 Thread Petr Savicky
if (is.na(a[i])) { return(f[i]*getCell(i-1)) } else { return(a[i]) } } x <- rep(NA, times=n) for (i in 1:n) { x[i] <- getCell(i) } identical(o, x) # [1] TRUE Petr Savicky. __ R-help@r-project.org ma

Re: [R] Upper an lower bound in linear programing

2012-05-24 Thread Petr Savicky
out Success: the objective function is 9 out$solution [1] 7.2 1.8 Hope this helps. Petr Savicky. __ 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] Optimizing problem R

2012-05-24 Thread Petr Savicky
meters and the call are library(lpSolve) f.obj <- c(0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1) f.rhs <- c(15, 35, 40, 0, 0, 0, 0, 0, 0, 0) f.dir = c("<=", "<=", "<=", rep(">=", times=7)) out <- lp("max", f.obj, f.mat,

Re: [R] Optimizing problem R

2012-05-23 Thread Petr Savicky
inear programming problem by introducing additional variables m1, m2, m3 and the constraints m1 <= a/10 m1 <= b/11 m2 <= aa/13 m2 <= bb/12 m2 <= cc/10 m3 <= bb/24 m3 <= cc/26 and maximizing m1 + m2 + m3. This problem may be solved using package lpSolve.

Re: [R] Median computation

2012-05-22 Thread Petr Savicky
sing apply(x,2,median) and this does not take much time. What do you mean by "choosing only those columns with same column name"? Petr Savicky. __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the po

Re: [R] Complex sort problem

2012-05-21 Thread Petr Savicky
rdered frequencies may be used for the reordered data. Hope this helps. Petr Savicky. __ 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] Complex sort problem

2012-05-18 Thread Petr Savicky
lowing. Calculate the order of the original data according to each relevant variable and store them as rank vectors determining the order of cases. Then, instead of sorting a data frame representing a sample, determine the order from the corresponding subset of the rank vector. This may be f

Re: [R] Optimization inconsistencies

2012-05-18 Thread Petr Savicky
ut <- lp("max", objective.in=crit, const.mat=mat, const.dir=dir, const.rhs=rhs) x <- low + out$solution round(x, digits=15) [1] -1 -1 -1 0 1 1 1 1 Hope this helps. Petr Savicky. __ R-help@r-project.org mailing list https://sta

Re: [R] Integration of two dimension function

2012-05-17 Thread Petr Savicky
is that G(cc) = 0.025 for cc = 0.025/log(4). I hope there are not too may errors in this calculation. Petr Savicky. __ 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.o

Re: [R] solve the equation in R

2012-05-17 Thread Petr Savicky
q(0.1, 20, length=1000) plot(a, f(a), ylim=c(-0.2, 0.2), type="l") abline(h=0) This suggests, that there is no root. This may also be obtained analytically. Hope this helps. Petr Savicky. __ R-help@r-project.org mailing list https://stat.e

Re: [R] Complex sort problem

2012-05-17 Thread Petr Savicky
an be done in linear time, so theoretically more efficiently than sorting. However, only a test may determine, what is more efficient in your situation. Hope this helps. Petr Savicky. __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listi

Re: [R] kolmogorov-Smirnov critical values

2012-05-16 Thread Petr Savicky
925540e-02 [44,] 0. 2.458672e-02 [45,] 0.3400 2.060188e-02 [46,] 0.3467 1.719140e-02 [47,] 0.3533 1.428992e-02 [48,] 0.3600 1.183727e-02 [49,] 0.3667 9.767969e-03 Hope this helps. Petr Savicky. __ R-help@r-proje

Re: [R] Probabilistic aggregation

2012-05-15 Thread Petr Savicky
1) For generating Z, use the function rnorm(), for computing the sample mean and sample estimate of the standard deviation, use functions mean() and sd(). Hope this helps. Petr Savicky. __ R-help@r-project.org mailing list https://stat.ethz.ch/mail

Re: [R] round up/down to nearest hundredth

2012-05-13 Thread Petr Savicky
a nearest multiple of 0.05. Rounding down and up to a nearest multiple of a unit u can be done as follows x <- 0.18 u <- 0.05 floor(x/u)*u # [1] 0.15 ceiling(x/u)*u # [1] 0.2 Hope this helps. Petr Savicky. __ R-help@r-project.org

Re: [R] Lowest year among several variables

2012-05-08 Thread Petr Savicky
following dat <- data.frame(x=c(80, 85, 90, 0), y=c(82, 76, 0, 0), z=c(83, 90, 86, 0)) dat[dat == 0] <- Inf out <- pmin(dat$x, dat$y, dat$z) out[out == Inf] <- 0 out [1] 80 76 86 0 Hope this helps. Petr Savicky. __ R-help@r

Re: [R] Translation of Linear minimization probelm from matlab to r

2012-05-08 Thread Petr Savicky
y >= 0 x + y <= 3 2*x + y <= 5 x + 2*y <= 5 then try library(lpSolve) crit <- c(3, 2) mat <- rbind(c(1, 1), c(1, 2), c(2, 1)) rhs <- c(3, 5, 5) dir <- rep("<=", times=3) out <- lp("max", objective.in=crit, const.mat=ma

Re: [R] How to do division calculation in R?

2012-05-06 Thread Petr Savicky
n of numbers can be done simply with "/" or "%/%". 2/3 # [1] 0.667 10/3 # [1] 3.33 10 %/% 3 # [1] 3 Please, clarify the question. Petr Savicky. __ R-help@r-project.org mailing list https://stat.ethz.ch/mailma

Re: [R] what is Non-numeric argument to mathematical function in prediction ?

2012-05-05 Thread Petr Savicky
The difference is that iris[,1] is not a dataframe, while both iris[,1:2] and iris[,1, drop=FALSE] are. Hope this helps. Petr Savicky. __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide

Re: [R] Breaking up a Row in R (transpose)

2012-05-04 Thread Petr Savicky
) + 1:2] <- matrix(orig[i, ], nrow=nrow(out), ncol=2, byrow=TRUE) } out [,1] [,2] [,3] [,4] [,5] [,6] [1,]563452 [2,]6743 64 [3,]799974 Hope this helps. Petr Savicky. _

Re: [R] estimation problem

2012-05-04 Thread Petr Savicky
On Fri, May 04, 2012 at 07:43:32PM +0200, Kehl Dániel wrote: > Dear Petr, > > thank you for your input. > I tried to experiment with (probably somewhat biased) truncated means > like in the following code. > How I got the 225 as a truncation limit is a good question. :) > > REPS1 <- REPS2 <- 100

Re: [R] Test if a sample mean of integers with range -inf; inf is different from zero

2012-05-04 Thread Petr Savicky
n expected value is s*X where s is uniform on {-1, 1} and X has value 2^i with probability 2^-i for i a positive integer. Hope this helps. Petr Savicky. __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE d

Re: [R] Equality of multiple vectors

2012-05-04 Thread Petr Savicky
s FALSE if one of the vectors is > different. Hi. Try the following. length(unique(list(vec1, vec2, vec3))) == 1 [1] FALSE length(unique(list(vec1, vec2, vec1))) == 1 [1] TRUE Hope this helps. Petr Savicky. __ R-help@r-project.org mailing list

Re: [R] Breaking up a Row in R (transpose)

2012-05-04 Thread Petr Savicky
[1,]79 [2,]99 [3,]74 Arr1 <- aperm(Arr, perm=c(2, 1, 3)) d <- dim(Arr1) t(array(Arr1, dim=c(d[1]*d[2], d[3]))) [,1] [,2] [,3] [,4] [,5] [,6] [1,]563452 [2,]674364 [3,]79997

Re: [R] Difference between 10 and 10L

2012-05-04 Thread Petr Savicky
> or > c(5,10) > versus > c(5L,10L) Hi. The help page ?"1L" or, equivalently, ?NumericConstants says An numeric constant immediately followed by ‘L’ is regarded as an ‘integer’ number when possible (and with a warning if it contai

Re: [R] means by group

2012-05-03 Thread Petr Savicky
t; "1,2" "1,2" "1,2" [4,] "2,1" "2,1" "2,1" "2,2" "2,2" "2,2" [5,] "2,1" "2,1" "2,1" "2,2" "2,2" "2,2" [6,] "2,1" "2,1&quo

Re: [R] estimation problem

2012-05-03 Thread Petr Savicky
he seed a bit The observation is that this cannot be improved much, since the estimate is based on a very small sample. The average size of the sample of nonzero values is N2/(N1+N2)*n = 29.1. So, the standard deviation should be something close to 100/sqrt(29.1) = 18.5376. Petr Savicky. ___

Re: [R] strange differences in vector operation versus manual calculation

2012-05-02 Thread Petr Savicky
are not Hi. The difference is caused by different placement of parenthesis. Replacing (1 + 10^(params[1]-xx)^params[2]) by (1 + 10^(params[1]-xx))^params[2] yields [1] 101.574364 101.057295 35.949148 6.428122 4.812942 which is equal to t5. Petr Savicky. __

Re: [R] Returning the coef from two coordinates

2012-04-29 Thread Petr Savicky
> x y > a 1 3 > b 2 2 > c 3 1 Hi. If you want three coefficients, one for each point in A, then try C <- sweep(A, 2, B) C[, 2]/C[, 1] [1] Inf 1 0 Petr Savicky. __ R-help@r-project.org mailing list https://stat

Re: [R] problem with break command

2012-04-26 Thread Petr Savicky
nt to generate a larger number of instances, which terminate below 5, try x <- matrix(runif(4*20, 0, 3), nrow=20, ncol=4) a <- matrix(0, nrow=4, ncol=5) a[col(a) > row(a)] <- 1 y <- x[rowSums(x) < 5, ] %*% a Petr Savicky. ___

Re: [R] problem with break command

2012-04-26 Thread Petr Savicky
ue loop variable, which controls the loop, since one can have a loop for (i in c(1, 1, 1, 1, 1)). The true control variable is hidden and cannot be changed. So the for loop for (i in 1:3) { for (i in 1:4) { cat("*") } cat("\n") }

Re: [R] comparison of bivariate normal distributions

2012-04-26 Thread Petr Savicky
ensity, more exactly a lower bound on the density. The area of an ellipse is \pi a b, where a, b, are its axes. If we have two such ellipses, it is possible to compute the area of their intersection, but again, for each ellipse, a lower bound on the density is

Re: [R] Create a new Vector based on two columns

2012-04-25 Thread Petr Savicky
ined, since the original data frame contains factors. If the intention is to keep character values, then use df$x1 <- ifelse(is.na(df$a), as.character(df$b), as.character(df$a)) df ab x1 1a1 a1 2 a1 a1 3 a2 a2 a2 4 b1 b1 5 b2 b2 b2 6b3 b3 7

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