stdsc¶
Purpose¶
Computes the population standard deviation of the elements in each column of a matrix.
Format¶
-
y =
stdsc(x)¶ - Parameters:
x (NxK matrix) – data
- Returns:
y (Kx1 vector) – the standard deviation of each column of x.
Examples¶
// Create 3 columns of random normal numbers
y = rndn(8100, 3);
// Calculate the standard deviation of each column
std = stdsc(y);
The return, in variable std is equal to:
1.00095980
0.99488832
1.00201375
Remarks¶
This function essentially computes:
sqrt(1/(N)*sumc((x - meanc(x)')2))
Thus, the divisor is \(N\) rather than \(N-1\), where \(N\) is the number of
elements being summed. See stdc() for the alternate definition.