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 X_i in X, return X_i-X_i-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,,]