R help - Nov 2009 - command similar to colSums for rowSums?

Working with an NxMxO sized matrix, currently I can do this in my code:

if (max(colSums(array)) >= number)

But to get an equivalent result using rowSums, I have to do:

for (i in 1:10)
{
if (max(rowSums(array[,,i])) >= number) 
}

I'm running both in a much larger loop that loops millions of times, so
speed and such is quite a big factor for me. Currently, the colSums line
uses about 1/10th as much time as the rowSums' for loop, and the for loop
actually took as much time as the rest of my code combined took to execute.
Is there a faster way than using a for loop and rowSums?
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Does this

  max(apply(yourArray, 3, rowSums))

give you what you want?

  -Peter Ehlers

Will Carr wrote:
> Working with an NxMxO sized matrix, currently I can do this in my code:
> 
> if (max(colSums(array)) >= number)
> 
> But to get an equivalent result using rowSums, I have to do:
> 
> for (i in 1:10)
> {
> if (max(rowSums(array[,,i])) >= number) 
> }
> 
> I'm running both in a much larger loop that loops millions of times, so
> speed and such is quite a big factor for me. Currently, the colSums line
> uses about 1/10th as much time as the rowSums' for loop, and the for
loop
> actually took as much time as the rest of my code combined took to execute.
> Is there a faster way than using a for loop and rowSums?

On Nov 30, 2009, at 11:10 AM, Will Carr wrote:
>
> Working with an NxMxO sized matrix, currently I can do this in my  
> code:
What are M, N, and O? All the same magnitude?
>
> if (max(colSums(array)) >= number)
>
> But to get an equivalent result using rowSums, I have to do:
>
> for (i in 1:10)
> {
> if (max(rowSums(array[,,i])) >= number)
What are you doing based on that if( ) determination?
> }
>
> I'm running both in a much larger loop that loops millions of times,  
> so
> speed and such is quite a big factor for me. Currently, the colSums  
> line
> uses about 1/10th as much time as the rowSums' for loop, and the for  
> loop
> actually took as much time as the rest of my code combined took to  
> execute.
Are you sure you are interpreting your profile results correctly?
> Is there a faster way than using a for loop and rowSums?
It may depend on what you are trying to do, which at the moment is  
most unclear.
> -- 
> View this message in context:
http://n4.nabble.com/command-similar-to-colSums-for-rowSums-tp931394p931394.html
> Sent from the R help mailing list archive at Nabble.com.
>
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