statcomp2 notes
Stat Comp at JSPH
Unix/Linux
- `chmod -w filename` , ur self
- `grep' : find text in file
Emacs
- `C-M-s ` : regexp search
- `C-x d ` : dir mode
- `M-5 c` : ccccc
- `M-x tetris `
- new command
- `\newcommand{}{}`
- `\newcommand{}[2] ...#1`
R
- `R BATCH inputfile outputfile &`
- `system("ls")`
- `break` : jump out of loop
- `next`: move to next loop
- `lapply`: apply FUN to each element in list
- `sapply` : same way, but return a vector or matrix if possible
Coding Practices
- start with WHO, WHEN , WHAT, HOW
- end with 'end of myfile.R'
- function star with WHAT,
- INPUT
- OUTPUT
- plan to spend 1/4 of your time commenting
R by Roger
- S3 , old style class (quick and dirty)
- S4, new style class (encourageed to use)
- mean.default
- your own methods:
- print/show
- summary
- plot
- example:
- setClass("polygon", representation(x="numeric", y="numeric"))
- setMethod("plot","polygon", function(x,y).....)
- p <- new("polygon", x=c(1,2,3,4),y=c(1,2,3,4))
- plot(p)
R Debug
- traceback
-
stepping through with debug
debug(function) undebug(function) Browse[2]> mu [1] 1 Browse[2]> n debug at #4: ss <- sum(d2) Browse[2]> d2 [1] 4 n : next c : rest of the function w/o stopping Q : quit where : where ls() - browser() , put inside the function
- trace
- trace with recover
-
options(error=recover) - cat() is more flexible than print()
R OO
- methods(summary)
- getS3method()
-
getAnywhere()
class(x) <- "roger" print.roger <- function(x, ...) cat(..fasmf)
R Package
- R
- man
- data
- demo
- exec : code for Perl and other system tools
- inst : doc vignette
- src
-
tests : R check
- DESCRIPTION
C
.Call
-
very useful in matrix :
allocMatrix(afsd, I, J)
Published
17 June 2012