percentChange

percentChange(X)

X is a vector or a matrix.

If X is a vector, for each element in X, compute the percentage change relative to the previous element. 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.

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);