similar to: Double summation limits

Displaying 15 results from an estimated 15 matches similar to: "Double summation limits"

2016 Apr 08
1
write a function inside the summation in a more condensed form
Dear R Experts that's my original equation > x=c(2,4) > Y1=sum(sapply(1:2,function(i){sum(sapply(1:i,function(j){(3^(x[i]+x[j]))}))})) > y1 [1] 7371 I want to write the inside function (3^(x[i]+x[j])) in a more condensed form cause this will help me when the multiple summations are more than two I've tried the following form >
2006 Oct 03
1
Summation in R
Hello! Maybe this is a trivial question as I'm still a new baby in R but I wish that u will help me. I want to calculate the following U= sum (t_j*v_j) where t_j is a vector and v_j is the matrix Thanks Dina
2008 Aug 29
1
more efficient double summation...
Dear R users... I made the R-code for this double summation computation http://www.nabble.com/file/p19213599/doublesum.jpg ------------------------------------------------- Here is my code.. sum(sapply(1:m, function(k){sum(sapply(1:m, function(j){x[k]*x[j]*dnorm((mu[j]+mu[k])/sqrt(sig[k]+sig[j]))/sqrt(sig[k]+sig[j])}))})) ------------------------------------------------- In fact, this is
2008 Nov 15
1
make a triple summation more efficient
Dear R users... I made the R-code for this triple summation computation http://www.nabble.com/file/p20517134/a.jpg ------------------------------------------------- Here is my code.. x=seq(.1,1,.1); l=10 y=seq(1,10); m=10 z=seq(.1,1,.1); n=10 sum(sapply(1:l, function(i) {sum(sapply(1:m, function(j) {sum(sapply(1:n, function(k){exp(x[i]*y[j]*z[k] )/gamma(y[j]+1)}))^(1.5) }))}))
2007 Oct 17
2
Need help with function that includes 2 summation
I am relatively new to R, so this may be a much simpler question than it seems to me. I am trying to create a function that includes two summations, and can't figure out how. I am attaching the equation as a pdf file. This function will then be optimized over a chosen range of values, but right now I just need help with the function. Thank you. Zack Darnell Duke University -- Zack
2011 Jul 11
1
Summation resulting in a list?
Probability <- function(N, f, m, b, x, t) { #N is the number of lymph nodes #f is the fraction of Dendritic cells (in the correct node) that have the antigen #m is the number of time steps #b is the starting position (somewhere in the node or somewhere in the gap between nodes. It is a number between 1 and (x+t)) #x is the number of time steps it takes to traverse the gap #t is the number
2009 Aug 20
1
how to compute this summation...
Dear R users, I try to compute this summation, http://www.nabble.com/file/p25054272/dd.jpg where f(y|x) = Negative Binomial(y, mu=exp(x' beta), size=1/alp) http://www.nabble.com/file/p25054272/aa.jpg http://www.nabble.com/file/p25054272/cc.jpg In fact, I tried to use "do.call" function to compute each u(y,x) before the summation, but I got an error, "Error in X[i, ]
2004 Mar 16
3
multiple summation
Hello, I have to compute a multiple summation (not an integration because the independent variables a are discrete) for all the values of a function of several variables f (x_1,...,x_n), that is sum ... sum f(x_1,...,x_n) x_1 x_n have you some suggestion? Is it possible? I know that for multiple integration there is the function adapt, but it has at most n=20. In my case n depends on the
2012 Oct 26
3
summation sign
Hi all, I have a very quick question on how to use the summation sign in R for the function. Here?s a basic example: the function is sum(i=1 to 5)log(1-xi^2) Id be grateful if someone knows how to do this without writing it out 5 times - I am looking sth along the lines of the following: computeR <- function(x) { return (-sum(log(1-x^2)) }^ thank you vm in advance! -- View this
2011 Jun 22
3
Help Needed on Merging Columns by Summation
Dear Sirs/Madam, I am a beginner to R, and I am currently working on a data matrix which looks like this: > head(oligo) ko:K00001 ko:K00003 ko:K00005 ko:K00008 ko:K00009 ko:K00010 ko:K00012 AAA 370 631 365 67 164 455 491 KAA 603 1208 170 157 68
2012 May 18
3
LM with summation function
Hi all, I'm trying to model some data where the y is defined by y = summation[1 to 50] B1 * x + B2 * x^2 + B3 * x^3 Hopefully that reads clearly for email. Anyway, if it wasn't for the summation, I know I would do it like this lm(y ~ x + x2 + x3) Where x2 and x3 are x^2 and x^3. However, since each value of x is related to the previous values of x, I don't know how to do this.
2005 Jun 15
2
need help on computing double summation
Dear helpers in this forum, This is a clarified version of my previous questions in this forum. I really need your generous help on this issue. > Suppose I have the following data set: > > id x y > 023 1 2 > 023 2 5 > 023 4 6 > 023 5 7 > 412 2 5 > 412 3 4 > 412 4 6 > 412 7 9 > 220 5 7 > 220 4 8 > 220 9 8 > ...... > Now I want to compute the
2012 Oct 18
7
summation coding
I would like to code the following in R: a1(b1+b2+b3) + a2(b1+b3+b4) + a3(b1+b2+b4) + a4(b1+b2+b3) or in summation notation: sum_{i=1, j\neq i}^{4} a_i * b_i I realise this is the same as: sum_{i=1, j=1}^{4} a_i * b_i - sum_{i=j} a_i * b_i would appreciate some help. Thank you. -- View this message in context: http://r.789695.n4.nabble.com/summation-coding-tp4646678.html Sent from the R
2012 Jun 27
32
[Bug 51477] New: bad/missing graphics with NV11 / GeForce 2MX/MX400
https://bugs.freedesktop.org/show_bug.cgi?id=51477 Bug #: 51477 Summary: bad/missing graphics with NV11 / GeForce 2MX/MX400 Classification: Unclassified Product: xorg Version: unspecified Platform: x86 (IA32) OS/Version: Linux (All) Status: NEW Severity: normal Priority: medium Component:
2010 Mar 20
2
summated scale
hello, I am new to R (convert from Stata) and I am wondering if there is an R command/function for generating a summated scale from, for example, four separate variables in a data set. In other words, I want to transform the variables x1, x2, x3, and x4 (which have high inter-item reliability) into one new summated variable x'. Can't seem to find it in the psy or psych package ...