deltas

Syntax

deltas(X, [n])

Arguments

X is a vector, matrix or table.

n (optional) is an integer specifying the step to shift when comparing elements in X. The default value is 1, meaning to compare the current element with the adjacent element at left.

Details

For each element Xi in X, return Xi-Xi-n, representing the differences between elements.

Return value: A vector/matrix/table with the same shape as X.

Examples

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

x=NULL 1 2 NULL 3;
deltas(x);
// output: [,,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
When n is a positive integer:
m=matrix(1 3 2 5 6, 0 8 NULL 7 6);
a=deltas(m,2)
a;
0 1
1
2 -1
4
When n is a negative integer:
m = 3 4 6 9
r2= deltas(m,-2)
r2; 
// output: [-3,-5,,]