Displaying 3 results from an estimated 3 matches for "rowdiff".
2011 Jul 13
1
UNIX diff function
Colleagues,
(R: 2.13.0; OS X)
I often receive sequential datasets in which there are new rows interposed between existing rows. For example:
SET1 <- data.frame(list(LETTERS=LETTERS[c(1:4, 6:10)], NUMBERS=c(1:4, 6:10)))
SET2 <- data.frame(list(LETTERS=LETTERS[1:10], NUMBERS=1:10))
> SET1
LETTERS NUMBERS
1 A 1
2 B 2
3 C 3
4 D 4
5
2000 Mar 29
2
regularly lattice & neighbors
Dear R-users,
Is there a procedure to identify neighbors in a regular lattice using either a
"rook" or a "queen" criterium? To be more specific, suppose:
My lattice:
1 2 3
4 5 6
7 8 9
"Rook" Neighbors
1 has neighbors 2,4
2 has neighbors 1,3,5
...
5 has neighbors 2,4,6,8
"Queen Neighbors"
1 has neighbors 2,4,5
2 has neighbors 1,3,4,5,6
For each case,
2013 Mar 13
1
calculating column difference in a matrix
Dear R users;
Consider the following toy example:
a <- matrix(c(2,3,4,NA,NA,5,8,NA,8,NA), 5, 2)
b <- cbind(a,apply(a, 1, diff, na.rm = TRUE))
What I would like be able to get is:
c <- matrix(c(2,3,4,NA,NA,5,8,NA,8,NA,3,5,-4,8,NA), 5, 3)
i.e., for each row if both values (column 1 and 2) are NA then the
difference must return NA, but if any of those two values is different
from NA