DIFF Difference Function
Section: Elementary Functions
Usage
y=diff(x) y=diff(x,k) y=diff(x,k,dim)
Produce difference of successive vector elements.
If x is a vector of length n, diff (x) is the
vector of first differences
\[
[x_2 - x_1, ..., x_n - x_{n-1}].
\]
If x is a matrix, diff (x) is the matrix of column
differences along the first non-singleton dimension.
The second argument is optional. If supplied, diff (x,k),
where k is a nonnegative integer, returns the
k-th differences. It is possible that k is larger than
then first non-singleton dimension of the matrix. In this case,
diff continues to take the differences along the next
non-singleton dimension.
The dimension along which to take the difference can be explicitly
stated with the optional variable dim. In this case the
k-th order differences are calculated along this dimension.
In the case where k exceeds size (x, dim)
then an empty matrix is returned.