R help - Oct 2003 - BEGINNER: please help me to write my VERY simple function

Hi.
1)I have two variables: call a<-c(e.g.0,3,6,7...)
                           b<-c(e.g.6,8,3,4...)
I want to create a third vector z wich contain the 
pairs values z<-c(0,6,3,8,6,3,7,4....and so on for each 
pairs (a,b)).
There is a specific function?
How can i write my own function?

2)When i try to write a function and then i save it 
like "function.R" file, i try to retrieve it with 
source comand. As result i obtain an error 
message "error in parse: sintax error on line...". I 
apply deparse() and i see an incorrect parsing: how 
avoid unwanted parsing?
Thanks.
Michele.

Michele Grassi wrote:
> Hi.
> 1)I have two variables: call a<-c(e.g.0,3,6,7...)
>                            b<-c(e.g.6,8,3,4...)
> I want to create a third vector z wich contain the 
> pairs values z<-c(0,6,3,8,6,3,7,4....and so on for each 
> pairs (a,b)).
> There is a specific function?
> How can i write my own function?
> 
For that, you don't need to.

help(expand.grid)

> 2)When i try to write a function and then i save it 
> like "function.R" file, i try to retrieve it with 
> source comand. As result i obtain an error 
> message "error in parse: sintax error on line...". I 
> apply deparse() and i see an incorrect parsing: how 
> avoid unwanted parsing?
I'm really not sure what you're trying to do with deparse here, but I 
don't think it's supposed to do what you meant.  The error message is 
what should be attended to - fix that with your favorite text editor.

Cheers

Jason
-- 
Indigo Industrial Controls Ltd.
http://www.indigoindustrial.co.nz
64-21-343-545
jasont at indigoindustrial.co.nz

Michele Grassi wrote:
>Hi.
>1)I have two variables: call a<-c(e.g.0,3,6,7...)
>                           b<-c(e.g.6,8,3,4...)
>I want to create a third vector z wich contain the 
>pairs values z<-c(0,6,3,8,6,3,7,4....and so on for each 
>pairs (a,b)).
>There is a specific function?
>How can i write my own function?
>
>2)When i try to write a function and then i save it 
>like "function.R" file, i try to retrieve it with 
>source comand. As result i obtain an error 
>message "error in parse: sintax error on line...". I 
>apply deparse() and i see an incorrect parsing: how 
>avoid unwanted parsing?
>Thanks.
>Michele.
>
>______________________________________________
>R-help at stat.math.ethz.ch mailing list
>https://www.stat.math.ethz.ch/mailman/listinfo/r-help
>  
>
1) a simple solution to the problem:
     define (for example):
     gen.pairs <- function(x,y){
          z<-as.vector(rbind(x,y))
          z
     }
    try:
  >   x<-1:10
  >   y<-11:20
  >  gen.pairs(x,y)
 [1]  1 11  2 12  3 13  4 14  5 15  6 16  7 17  8 18  9 19 10 20

2) a) you can write the definition to a file and then use  source this file.
          If the file name is   myfun.R  
              > source("myfun.R")
           will work. But only if there are no errors in the definition
     b) you can type in the code of the definition after the R prompt
">"
     c) you can type in :
              > gen.pairs <- function(x,y) { z }
          and complete the definition by using edit:
              > edit(gen.pairs)
      However, syntax errors are not allowed!   

Peter

On 21-Oct-03 Michele Grassi wrote:
> Hi.
> 1)I have two variables: call a<-c(e.g.0,3,6,7...)
>                            b<-c(e.g.6,8,3,4...)
> I want to create a third vector z wich contain the 
> pairs values z<-c(0,6,3,8,6,3,7,4....and so on for each 
> pairs (a,b)).
> There is a specific function?
> How can i write my own function?
The following will do what you want, though I don't know whether
there is a simpler way to do it.

  z <- rbind(a,b) ; z <- as.vector(z)

For example:
> a <- c(1,3,5,7) ; b <- c(2,4,6,8)
> z <- rbind(a,b) ; z <- as.vector(z) ; z
[1] 1 2 3 4 5 6 7 8

Best wishes,
Ted.



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E-Mail: (Ted Harding) <Ted.Harding at nessie.mcc.ac.uk>
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Date: 21-Oct-03                                       Time: 11:27:02
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