R help - Aug 2008 - Newbie: Examples on functions callling a library etc.

Hello

 

R is pretty new to me. I need to write a function that returns three
matrices of different dimensions.  In addition, I need to call a function
from a contributed package with the function.   I have browsed several
manuals and docs but the examples on them are either very simple or
extremely hard to follow.

 

Many thanks

 

Ed

 

 

 


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Eduardo M. A. M.Mendes <emammendes <at> gmail.com> writes:
> R is pretty new to me. I need to write a function that returns three
> matrices of different dimensions.  In addition, I need to call a function
> from a contributed package with the function.   I have browsed several
> manuals and docs but the examples on them are either very simple or
> extremely hard to follow.
> 
> Many thanks
> 
> Ed
> 
  I think you need to try to specify your needs a little bit
more carefully.  Here is a function that technically meets
your needs:

library("example_pkg")  ## to load the contributed package
myfunction <- function() {  ## function with no arguments
   foo()                    ## assuming the function "foo" is in the
package
   list(matrix(nrow=2,ncol=2),matrix(nrow=3,ncol=3),matrix(nrow=4,ncol=4)
}

  But I suspect that doesn't really do what you need ...

  Ben Bolker

Hi Ed, 

Here's a simple example showing your needs:


myfun <- function(n1, n2, n3) {
  mat1 <- matrix(rep(1), nrow = n1, ncol = 3)
  mat2 <- matrix(rep(2), nrow = n2, ncol = 4)
  mat3 <- matrix(rep(3), nrow = n3, ncol = 5)

  require("survival") ## make sure the package you need is loaded
  mypkgfun <- survival::is.Surv ## Use the '::' and ':::'
extractors to get visible and hidden functions respectively from the package

  list(mat1 = mat1, mat2 = mat2, mat3 = mat3, mypkgfun = mypkgfun) ## Return the
items in a list
}

## Now invoke the function
foo <- myfun(n1 = 1, n2 = 1, n3 = 5)

## and look at the returned results
foo
> myfun <- function(n1, n2, n3) {
+   mat1 <- matrix(rep(1), nrow = n1, ncol = 3)
+   mat2 <- matrix(rep(2), nrow = n2, ncol = 4)
+   mat3 <- matrix(rep(3), nrow = n3, ncol = 5)
+ 
+   require("survival")
+   mypkgfun <- survival::is.Surv
+ 
+   list(mat1 = mat1, mat2 = mat2, mat3 = mat3, mypkgfun = mypkgfun)
+ }
> 
> foo <- myfun(n1 = 1, n2 = 1, n3 = 5)
> 
> foo
$mat1
     [,1] [,2] [,3]
[1,]    1    1    1

$mat2
     [,1] [,2] [,3] [,4]
[1,]    2    2    2    2

$mat3
     [,1] [,2] [,3] [,4] [,5]
[1,]    3    3    3    3    3
[2,]    3    3    3    3    3
[3,]    3    3    3    3    3
[4,]    3    3    3    3    3
[5,]    3    3    3    3    3

$mypkgfun
function (x) 
inherits(x, "Surv")
<environment: namespace:survival>
> 
HTH

Steve McKinney


-----Original Message-----
From: r-help-bounces at r-project.org on behalf of Eduardo M. A. M.Mendes
Sent: Thu 8/28/2008 5:43 PM
To: r-help at r-project.org
Subject: [R] Newbie:  Examples on functions callling a library etc.
 
Hello

 

R is pretty new to me. I need to write a function that returns three
matrices of different dimensions.  In addition, I need to call a function
from a contributed package with the function.   I have browsed several
manuals and docs but the examples on them are either very simple or
extremely hard to follow.

 

Many thanks

 

Ed

 

 

 


	[[alternative HTML version deleted]]

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