Differentiate or difference.
DIFF may be called with either numeric or symbolic arguments.
For a numeric vector argument, DIFF computes differences.
DIFF(X), for a vector X, is [X(2)-X(1) X(3)-X(2) ... X(n)-X(n-1)].
DIFF(X), for a matrix X, is the matrix of column differences,
[X(2:n,:) - X(1:n-1,:)].
DIFF(X,n) is the n-th difference function.
For a symbolic (string) argument, DIFF uses the Maple Symbolic Toolbox
to compute derivatives.
DIFF(S) differentiates S with respect to its free variable.
DIFF(S,'v') differentiates S with respect to 'v'.
DIFF(S,n) and DIFF(S,'v',n) differentiate S n times.
DIFF, with no arguments, differentiates the previous expression.
With numeric arguments:
h = .001; x = 0:h:pi;
diff(sin(x.^2))/h is an approximation to 2*cos(x.^2).*x
diff((1:10).^2) is 3:2:19
With symbolic arguments and the Maple Symbolic Toolbox:
diff('sin(x^2)') is '2*cos(x^2)*x'
diff sin(x^2) is also '2*cos(x^2)*x'
diff('t^6',6) is '720'.
See also GRADIENT , DEL2 , INT, SYMVAR.