contourc

Purpose

Contour plot computation.

Synopsis

C = contourc(Z)
C = contourc(Z,n)
C = contourc(Z,v)
C = contourc(x,y,Z)
C = contourc(x,y,Z,n)
C = contourc(x,y,Z,v)

Description

contourc calculates the contour matrix C used by the M-file contour to draw actual contour plots.

C = contourc(Z) computes the contour matrix for a contour plot of matrix Z. The contours are level lines in the units of Z. The number of contour lines and their corresponding values are chosen automatically by contourc.

C = contourc(Z,n) computes contours of matrix Z with n contour levels.

C = contourc(Z,v) computes contours of Z with contour levels at the values specified in vector v.

C = contourc(x,y,Z), C = contourc(x,y,Z,n), and C = contourc(x,y,Z,v) compute contours of Z and use the data in vectors x and y to control the axis scaling on the x- and y-axes. The elements of x and y are equally spaced.

The contour matrix C is a two-row matrix of contour lines. Each contiguous drawing segment contains the value of the contour, the number of (x,y) drawing pairs, and the pairs themselves. The segments are appended end-to-end,

C = [level1  x1  x2  x3...level2  x2  x2  x3...;
     pairs1  y1  y2  y3...pairs2  y2  y2  y3...]

Limitations

contourc assumes that vectors x and y are monotonically increasing. If x and y are irregularly spaced, the contours are simply stretched apart, which is not the same as contouring the irregularly spaced data.

See Also

contour, contour3

(c) Copyright 1994 by The MathWorks, Inc.