delayed-ops {matter} | R Documentation |
Some arithmetic operations are available as delayed operations on matter
objects. With these operations, no data is changed on disk, and the operation is only executed when elements of the object are actually accessed.
Currently the following operations are supported:
‘Arith’: ‘+’, ‘-’, ‘*’, ‘/’, ‘^’
‘Compare’: ‘==’, ‘>’, ‘<’, ‘!=’, ‘<=’, ‘>=’
‘Math’: ‘exp’, ‘log’, ‘log2’, ‘log10’
Delayed operations are applied at the C++ layer immediately after the elements are read from disk. This means that operations that are implemented in C and/or C++ for efficiency (such as summary statistics) will also reflect the execution of the delayed operations.
A new matter
object with the registered delayed operation. Data on disk is not modified; only object metadata is changed.
Kylie A. Bemis
x <- matter(1:100) y <- 2 * x + 1 x[1:10] y[1:10] mean(x) mean(y)