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diff

(/tools/hpmatlab/toolbox/matlab/datafun/diff.m)

Function Synopsis

X = diff(X,nd,arg3)

Help text

DIFF	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 Symbolic Math 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.

	Examples;
	    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.

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Produced by mat2html on Wed Feb 8 12:25:18 EST 1995
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