percentChange

percentChange(X, [n])

X is a vector or a matrix.

n (optional) is an integer specifying the number of elements to shift when comparing the current element to another element in X. The default value is 1, meaning the reference is the adjacent element at right.

• If X is a vector, return a vector containing the percentage changes between elements.

  • If n is a positive integer, it calculates the percentage change of the current element compared to the element spaced (n-1) to the left. percentChange = (currentElement / leftReferenceElement) - 1

  • If n is a negative integer, it calculates the percentage change of the current element compared to the element spaced (n-1) to the right. percentChange = (currentElement / rightReferenceElement) - 1

• 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.

percentChange([1,2,3]);
// output: [,1,0.5]

percentChange(85 90 95);
// output: [,0.058824,0.055556]

m=matrix(100 105 109 112 108 116, 200 212 208 199 206 210);
m

percentChange(m);

r = percentChange(1..10,3);
r;
// output: [,,,3,1.5,1,0.75,0.6,0.5,0.43]

m=matrix(1 3 2 NULL 6 9 3, 0 8 NULL 7 6 2 8);
r = percentChange(m,2);
r;

m = 3 4 6 9
r2= percentChange(m,-2)
r2; // output: [-0.5,-0.56,,]