Displaying 1 result from an estimated 1 matches for "rowstochange".
2003 Feb 09
0
to modify a matrix : Summary
...;- x[,2]*(1+4*(x[,1]==3))
good result, a little bit tricky.
(2) x[,2] <- ifelse(x[,1]==3, x[,2]*5, x[,2])
good result, easy to be understood.
(3) for(i in 1:5) {if (x[,1]==3) {x[,2] <- 5*x[,2]}}
unable to get any modification, theoretically easily undrstandable
from a programmer.
(4) rowstochange <- x[,1]==3
x[rowstochange,2] <- x[rowstochange,2]*5
good result, to give many suggetions.
When I excute "rowstochange <- x[,1]==3", I have
> rowstochange
[1] FALSE FALSE TRUE FALSE FALSE .
This is my first time to realize the meaning of the
expression of "x[,1]...