margin.table
Compute Table Margin
Description
Computes the sum of values in a table over the specified margins.
Usage
marginSums(x, margin = NULL)
margin.table(x, margin = NULL)
Arguments
  
| x | a numeric matrix, table, or array. | 
  | margin | a vector of integers or character strings defining which margins over which to sum.
For example, if x is a matrix, margin=1 indicates rows
and margin=2 indicates columns.
If character strings, they are expected to be a subset of names(dimnames(x)). Note that margin tells which dimensions of x are retained
in the result.  
 If margin is NULL, sum of x is returned.
 | 
 
Details
This function returns a vector or an array that is the result of applying the sum 
function on x with the specified margin if margin is not NULL, 
or the sum of x if margin is NULL.  
The dimension size and dimension names of the computed array are extracted 
as dim(x)[margin] and dimnames(x)[margin], respectively. 
The returned vector or array has the same class as x.
Value
returns a numeric vector or array that is the result of applying the sum function 
on x with the specified margin if margin is not NULL, 
or sum of x if margin is NULL.
Note
Version 4.0.0 of open-source R introduced a new name, marginSums,
for the old margin.table function, in the hopes that its purpose
would be more obvious.  The functions are identical.
See Also
Examples
x <- array(1:24, dim = c(4, 3, 2),
    dimnames=list(A=NULL, B=paste0("b",1:3), C=NULL))
marginSums(x, c(2, 3))
marginSums(x, c("B", "C"))
marginSums(x, 1)
margin.table(x)