deltas

deltas(X)

X is a scalar/vector/matrix.

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.

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

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

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

deltas(m);