deltas

Syntax

deltas(X)

Arguments

X is a scalar/vector/matrix.

Details

If X is a vector, return a vector containing the subtractions between adjacent elements. The first element of the result is always NULL.

If X is a matrix, conduct the aforementioned calculation within each column of X. The result is a matrix with the same shape as X.

Examples

$ x=7 4 5 8 9;
$ deltas(x);
[,-3,1,3,1]
// equivalent to [, 4-7, 5-4, 8-5, 9-8]

$ x=NULL 1 2 NULL 3;
$ deltas(x);
[,,1,,]

$ m=matrix(1 3 2 5 6, 0 8 NULL 7 6);
$ m;

#0	#1
1	0
3	8
2
5	7
6	6

$ deltas(m);

#0	#1
2	8
-1
3
1	-1