Passing values to a function when using apply

Hi All

Slightly lost on how should I pass values to a function I am calling
using apply.


apply( veh_drg_animal1[ , c("readCount","gene_length")] ,1,  stats() )

here stats is a custom function where I want to pass two parameters
from data frame as shown and a third argument which is constant per
instance of apply.


stats <- function ( arg1,agr2,agr3) {
## computation using three parameters
}

Try this:

apply( veh_drg_animal1[ , c("readCount","gene_length")] ,1, ?stats, agr3 =
your_constant)


On Tue, Apr 27, 2010 at 3:10 PM, Abhishek Pratap <abhishek.vit at gmail.com>
wrote:

Hi All

Slightly lost on how should I pass values to a function I am calling
using apply.


apply( veh_drg_animal1[ , c("readCount","gene_length")] ,1, ?stats() )

here stats is a custom function where I want to pass two parameters
from data frame as shown and a third argument which is constant per
instance of apply.


stats <- function ( arg1,agr2,agr3) {
## computation using three parameters
}

--
Henrique Dallazuanna
Curitiba-Paran?-Brasil
25? 25' 40" S 49? 16' 22" O

try this:

apply(veh_drg_animal1[ ,c("readCount","gene_length")] ,1,
function(x)stats(x[1], x[2], total=55000000))

Henrique Dallazuanna wrote:

try this:

apply(veh_drg_animal1[ ,c("readCount","gene_length")] ,1,
function(x)stats(x[1], x[2], total=55000000))

I agree with this, that was my point in my original reply. ?Apply is *not*
passing 2 arguments simply because you are selecting two columns of the
input object, it's passing *one argument*, which is the *entire row* of the
input object. ?You can then access them individually within the stats
function, as Henrique shows.

Hi Guys

Thank you for clearing something I dint know. Just wondering the
reason of putting the word function(x)  in the apply function when we
have already declared stats function separately.

I better understand how the arguments are passed.

Thanks!
-Abhi

Abhishek Pratap wrote:

Hi Guys

Thank you for clearing something I dint know. Just wondering the
reason of putting the word function(x) ?in the apply function when we
have already declared stats function separately.

I better understand how the arguments are passed.

Thanks!
-Abhi

That's creating a *new* function, one without a name, that basically "breaks
up" the x argument into two values, and passes those along with the third
argument and passes these to your stats function. ?You either have to write
stats to accept two arguments, or leave stats accepting three arguments and
use this method.