similar to: Another good optimization (for PPC only, though)

Displaying 20 results from an estimated 3000 matches similar to: "Another good optimization (for PPC only, though)"

2009 Jun 19
1
Drawing dendrogram
Dear all, I would like to draw a dendrogram and mark some parts/branches (by using "segments") including their labels. If I draw it without specifying the length of x axix, I am able to do that (as in My dendrogram 1 of the following codes). However, if I want to specify the x axix, I am not able to draw marking line (by using "segments") including labels (as in My dendrogram
2001 Feb 03
1
fast math optimization patch
This patch adds two files, fast_math.[ch]. These files includes a couple faster versions of the libm routines that don't provide all the semantics and accuracy of the IEEE versions (but are still pretty darn accurate). Typically there are situations in which full precision is not necessary and the following patch tries to apply this approach. I don't know whether this patch will
2012 Jul 29
1
Return od functions
Hi! I have some questions about R function. I try to write a function for multi-returns. The function code is as attachment. dgp.par<-function(ai, bi, t, n) { t0<-t+20 y0<-matrix(0, nr=t0, nc=n) y0[1,]<-ai/(1-bi) for(tt in 2:t0) { y0[tt,]<-ai+bi*y0[tt-1,]+rnorm(n, 0, 1) } y<-y0[21:t0,] x<-y0[20:t0-1,] z<-y0[19:t0-2,] z<-z[2:t,] dy<-y[2:t,]-y[1:t-1,]
2010 Apr 29
1
Request - adding recycled "lwd" parameter to polygon
Hello dear members of R-help and R-core mailing list, I am not sure if this request is a "ticket" that should be filled somewhere outside the mailing list. If so, I apologize for not doing and would like to know where I should have filled it. And to the subject matter: I would like to use a command like this: plot(c(1,8), 1:2, type="n") polygon(1:7, c(2,1,2,NA,2,1,2),
2010 Apr 29
1
Request - adding recycled "lwd" parameter to polygon
Hello dear members of R-help and R-core mailing list, I am not sure if this request is a "ticket" that should be filled somewhere outside the mailing list. If so, I apologize for not doing and would like to know where I should have filled it. And to the subject matter: I would like to use a command like this: plot(c(1,8), 1:2, type="n") polygon(1:7, c(2,1,2,NA,2,1,2),
2009 Oct 02
1
suggest enhancement to segments and arrows to facilitate horizontal and vertical segments
I suggest a simple enhancement to segments() and arrows() to facilitate drawing horizontal and vertical segments -- set default values for the second x and y arguments equal to the first set. This is handy, especially when the expressions for coordinates are long. Compare: Segments: < function (x0, y0, x1 = x0, y1 = y0, col = par("fg"), lty = par("lty"), --- > function
2008 Feb 16
1
Evaluate function on a grid
I have a function in R^2, say f <- function(x,y) { ...skipped } I want to plot this function using contour, persp. wireframe, etc. I know that the function has a global minimum at (x0, y0) The naive approach is to evaluate the function on the outer product of two arrays, like this: sx <- c(seq(-3, x0, len = 100), seq(x0, 3, len = 100)[-1]) sy <- c(seq(-3, y0, len = 100), seq(y0, 3,
2010 May 03
3
how to rewrite this for loops in matrix form without loop
x0=rnorm(100) y0=rpois(100,3)+1 ind=as.data.frame(table(y0)) ind1=ind[,1] ind2=ind[,2] phi=NULL for (i in 1:length(ind2)){ phi[i]=sum(x0[y0==ind1[i]])/ind2[i] } [[alternative HTML version deleted]]
2006 Dec 02
1
Trouble passing arrays to C code
Hello, I'm having more trouble with interfacing with C code. I have a function in C that will return the result of its computation as 3 arrays. The signature of the function is as follows: void lorenz_run(double x0, double y0, double z0, double h, int steps, double *res_x, double *res_y, double *res_z) The function works, as I've tested it from within C itself and the results
2017 Jun 19
1
arrows: no vectors for "code" and "angle" parameters
I was teaching new R users to make some fun graphs. I had some arrows examples worked up we came across a problem. The arrows function ignores 2nd and following elements of vectors given as code an angle. Would you please consider 1) allowing vectors for code and angle, or 2) returning an error or warning when user mistakenly supplies a vector for those parameters? When code like this is
2008 Nov 17
2
re sults from "do.call" function
Dear R users... I made this by help of one of R users. _________________________________________________________________ X=matrix(seq(1,4), 2 , 2) B=matrix(c(0.6,1.0,2.5,1.5) , 2 , 2) func <- function(i,y0,j) { y0*exp(X[i,]%*%B[,j]) } list1 <- expand.grid( i=c(1,2) , y0=c(1,2) , j=c(1,2) ) results <- do.call( func , list1 )
2011 Aug 08
1
problem in do.call function
Dear all, I am trying to use "do.call", but I don't think I totally understand this function. Here is an simple example. -------------------------------------------- > B <- matrix(c(.5,.1,.2,.3),2,2) > B [,1] [,2] [1,] 0.5 0.2 [2,] 0.1 0.3 > x <- c(.1,.2) > X <- cbind(1,x) > X x [1,] 1 0.1 [2,] 1 0.2 > > lt <-
2009 Dec 01
2
Starting estimates for nls Exponential Fit
Hello everyone, I have come across a bit of an odd problem: I am currently analysing data PCR reaction data of which part is behaving exponential. I would like to fit the exponential part to the following: y0 + alpha * E^t In which Y0 is the groundphase, alpha a fluorescence factor, E the efficiency of the reaction & t is time (in cycles) I can get this to work for most of my reactions,
2008 Apr 16
1
segments() with zero-length arguments (PR#11192)
Uwe Ligges suggested I post this on R-bugs as a wishlist item with a proposed patch. R considers zero-length arguments to segments() to be an error. I would like R to allow this and to return without an error. It occurs naturally in settings like valid <- c(FALSE, FALSE, FALSE) segments(x0[valid], y0[valid], x1[valid], y1[valid]) For what it may be worth, S-Plus does not consider
2017 Apr 26
2
Store unswitch
Hi, Yes, I can see why that would not work. The sinking algorithm in SimplifyCFG isn't particularly clever. In particular it can't reason about memory ordering and aliasing. In unswitch1(), it can identify that the stores correlate because the correlating stores appear in the same relative source order. In unswitch2() they have been permuted, and the algorithm cannot deal with this. This
2005 May 05
3
documenation for arrows() is backwards (PR#7839)
Full_Name: Michael Hoffman Version: 2.1.0 OS: Linux (Fedora Core 3, kernel 2.6.11-1.14_FC3) Submission from: (NULL) (193.62.199.8) help(arrows) says: """ arrows(x0, y0, x1, y1, length = 0.25, angle = 30, code = 2, col = par("fg"), lty = NULL, lwd = par("lwd"), xpd = NULL) ... If 'code=2' an arrowhead is drawn at
2012 Oct 30
1
mapply instead for loop
Hi all!   My question in about using mapply instead for loop. Below is a example with for loop: Is it posible to give same results with mapply function?   Thanks for help!   OV   x <- 1:10 y <- 1:10 xyz <- data.frame(expand.grid(x,y)[1], expand.grid(x,y)[2], z = rnorm(100)) names(xyz) <- c("x", "y", "z") head(xyz) size <- 2 output <- NULL   ### for
2012 Oct 18
3
Upper limit in nlsLM not working as expected
Dear all, I am using the nlsLM function to fit a Lorentzian function to my experimental data. The LM algorithm should allow to specify limits, but the upper limit appears not to work as expected in my code. The parameter 'w', which is peak width at half maximuim always hits the upper limit if the limit is specified. I would expect the value to be in-between the upper and lower limit with
2011 Aug 08
3
on "do.call" function
Dear all, Even though one of R users answered my question, I cannot understand, so I re-ask this question. I am trying to use "do.call", but I don't think I totally understand this function. Here is an simple example. -------------------------------------------- > B <- matrix(c(.5,.1,.2,.3),2,2) > B [,1] [,2] [1,] 0.5 0.2 [2,] 0.1 0.3 > x <- c(.1,.2) >
2011 Feb 04
3
uniroot
Hi, I am using the uniroot function in order to carry out a bivariate Monte Carlo simulation using the logistics model. I have defined the function as: BV.FV <- function(x,y,a,A) (((x^(-a^-1)+y^(-a^-1))^(a-1))*(y^(a-1/a))*(exp(-((1^(-a^-1)+y^(-a^-1))^a)+y^-1)))-A and the procedure is as follows: Randomly generate values of A~(0,1), y0 = -(lnA)^-1 Where: A=Pr{X<xi|Y=yi-1} and a is the