similar to: lazy evaluation question

Displaying 20 results from an estimated 20000 matches similar to: "lazy evaluation question"

2010 May 10
3
scope of a function + lazy evaluation
Hey guys, I have a doubt here , It is something simple I guess, what am I missing out here ?? f <- function(y) function() y tmp <- vector("list", 5) for (i in 1:5) tmp[[i]] <- f(i) tmp[[1]]() # returns 5; z <- f(6) tmp[[1]]() # still returns 5; it should return 6 "ideally" right ??? Even if I dont evaluate the function tmp[[1]] before i.e I do rm(list=ls()) f
2009 Aug 05
4
A question regarding R scoping
I have a question related to scoping. Suppose we have 2 functions: f1 = function(i){i = 1} f2 = function(n){ i = length(n) f1(i) } In other words, I would like i=1 regardless of n. Is this possible without having f1 in the body of f2? Thanks in advance!
2009 Jan 28
1
evaluation revisited
I'm still going over old emails and trying to get my head around evaluation so I'm persistent if nothing else. A while back , an expert sent me below as an exercise in understanding and I only got around to it tonight. I understand some of the output but not all of it and I put "Why not Zero ?" next to the ones that I don't understand based on my reading of the various
2009 Mar 31
1
error when going through Alan Lenarcic's package Tutorial
Hi Everyone: I've been going through Alan Lenarcic's package tutorial but when I did R CMD SHLIB Xdemo.cc Xdemo_main.cc -o Xdemo.dll I got the following error: XDemo_res.rc:15:38: warning: missing terminating " character XDemo_res.rc:23:34: warning: missing terminating ' character c:\mark\research\Rtools\MinGW\bin\windres.exe: XDemo_res.rc:16: syntax error
2008 Sep 23
4
perl expression question
If I have the string below. does someone know a regular expression to just get the "BLC.NYSE". I bought the O'Reilley book and read it when I can and I study the solutions on the list but I'm still not self sufficient with these things. Thanks. stock<-"/opt/limsrv/mark/research/equity/projects/testDL/stock_data/fhdb/US/BLC.NYSE"
2009 Nov 13
4
processing log file
Dear all, I'm trying to process a log file which logs the date, the username and the computer number accessed. The table looks like this: >table.users          Date UserName Machine 1  2008-11-25     John     641 2  2008-11-25    Clive     611 3  2008-11-25   Jeremy     641 4  2008-11-25     Walt     722 5  2008-11-25     Tony     645 6  2008-11-26     Tony     645 7  2008-11-26    
2012 May 14
2
Inf and lazy evaluation
Hi, I have a question involving Inf, lazy evaluation, and maybe argument recycling. I have a directory where I am trying to check for the existence of files of a certain pattern, basically something like "filename-#", where # is an integer. I can do something like this, which works. file.exists(paste(filename, "-", 1:100, sep = "")) But I don't like the fact
2006 Jun 16
2
scatterplot but a little tricky
i have two vectors of numbers x and y and of course i can do the standard scatterplot plot(x,y) and it looks fine. But, I was hoping there was a way to do the scatterplot so that each point plotted is a number where the number represents the index in the dataset. so, if it was x[3] and y[3], then the point would be a 3 or if it was x[4] and y[4], then the point would be a 4 etc. i doubt this is
2006 Jul 05
2
apologes if you already saw this :efficiency question
hi everyone : i'm not sure if my previous mail about this got sent. i was typing and erroneosuyl hit a button and lost what i was typing. anyway, i have the code below ( it works ) in which i run through the rows of a dataframe, taking out the first two fields which are characters strings ( with some extra spacing so i yuse gsub) and appending these character strings to a list so that i can
2006 Jul 06
2
[Fwd: as.data.frame question]
>From: markleeds at verizon.net >Date: Thu Jul 06 13:16:42 CDT 2006 >To: markleeds at verizon.net >Subject: as.data.frame question >hi all : as a result of an lapply command, >i get the following output. > > >$AAA > 000106 000107 000108 > 5.5 6.5 3.0 > >$BBB > 000106 000107 000108 > 4 5 6 > >$CCC
2009 Jun 01
1
Fwd: subset dataframe/list
--- the forwarded message follows --- -------------- next part -------------- An embedded message was scrubbed... From: "Cecilia Carmo" <cecilia.carmo at ua.pt> Subject: Re: [R] subset dataframe/list Date: Mon, 01 Jun 2009 21:33:15 +0100 Size: 3657 URL: <https://stat.ethz.ch/pipermail/r-help/attachments/20090601/921f7638/attachment-0002.mht>
2008 Jul 05
3
trying to superimpose a line plot onto a histogram
Hello, I'm trying to superimpose a line plot onto a histogram but I'm not having any luck. I've attached the dataset. What I did was: > hist(data,freq=F) Now I'm trying to superimpose the following points with a line connecting them onto the histogram: x y 100 0.535665393824959 200 0.212744329736556 300 0.0844933242968584 400 0.0335572838043417 500
2001 Mar 22
1
lazy evaluation and DUP=F
I am having some difficulty understanding the implication of lazy evaluation mixed with DUP=F in a .Fortran call. In qr.qty from base DUP is not used as an argument so defaults to T. I am calling qr.qty with a very large array and would like to set DUP=F in the .Fortran call so that qr.qty would be defined as copied below. Is there some risk that a variable used as the argument in the original
2009 Apr 01
1
problems with package tutorial
Hi: Here's my revised attempt at explaining my problem. Hopefully it won't get sent out weirdly like it did earlier. ? The link to what I'm trying to follow is http://www.stat.columbia.edu/~gelman/stuff_for_blog/AlanRPackageTutorial.pdf ? I've been going through the tutorial but when I got to page 9 and did R CMD SHLIB Xdemo.cc Xdemo_main.cc -o Xdemo.dll I got
2009 Feb 05
4
eval and as.name
I'm sure there is a more general way to ask this question but how do you use the elements of a character vector as names of objects in an expression? For example, say you have: a = c(1,3,5,7) b = c(2,4,6,8) n=c("a","b") and you want to use the names a and b in a function (e.g. sum) sum(eval(as.name(n[1])),eval(as.name(n[2]))) works but what is a simpler way to
2009 Feb 11
2
error in my previous message
i'm sorry. i had an error in my previous code because i left out a letter in the rownames. while fixing that, i also found a solution. so i'm sorry for the confusion. below is my fix. temp2 <- matrix(rnorm(10),nc=1,nrow=10) rownames(temp2) <-
2006 Jun 20
2
strange use of sapply
I've tried and give up. I have a matrix of say 200 columns and 400 rows. For each odd ( or even i suppose if i wanted to )column, I want to know the number of rows in which the value is greater than zero. So, I did sapply(tempMatrix,2,function(x) sum( x > 0 )) this almost works but i don't know how to tell it to only do the odd columns. my guess is , like everything else in R, this
2008 May 01
2
regular expression question
I have strings of the form TICKER.GGG.XXXXXX.dat but GGG is not always three characters so I can't use substr to pull it out of the string. Could someone tell me how to use sub to pull out the GGG but more generally the string between the dot after the R in TICKER and the next dot. I still don't have a very good understanding of regular expressions but I'm trying to get that
2009 Aug 20
2
Problem using findVar( ) in combination with R's lazy evaluation
Hi All, I have a few small questions about the usage of the C findVar( ) function when used in C code called with '.Call'. In my case I create an R function with an argument. This function calls some C code in which I use findVar( ) to retrieve the values from the argument. Ofcourse normally I would just give the values as argument to .Call, but in my project I need to use findVar for
2009 Mar 03
4
regular expression question
can someone show me how to use a regular expression to break the string at the bottom up into its three components : (-0.791,-0.263] (-38,-1.24] (0.96,2.43] I tried to use strplit because of my regexpitis ( it's not curable. i've been to many doctors all over NYC. they tell me there's no cure ) but it doesn't work because there also dots inside the brackets. Thanks.