Low-level contour plot computation
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)
contourc calculates the contour matrix C used
by contour, contour3, and contourf.
The values in Z determine the heights of the contour
lines with respect to a plane. The contour calculations use a regularly
spaced grid determined by the dimensions of Z.
C = contourc(Z) computes
the contour matrix from data in matrix Z, where Z must
be at least a 2-by-2 matrix. The contours are isolines in the units
of Z. The number of contour lines and the corresponding
values of the contour lines are chosen automatically.
C = contourc(Z,n) computes
contours of matrix Z with n contour
levels.
C = contourc(Z,v) computes
contours of matrix Z with contour lines at the
values specified in vector v. The length of v determines
the number of contour levels. To compute a single contour of level k,
use contourc(Z,[k k]).
C = contourc(x,y,Z), C
= contourc(x,y,Z,n), and C = contourc(x,y,Z,v) compute
contours of Z using vectors x and y to
determine the x and y values. x and y must
be monotonically increasing.
For more information on the contour matrix, see the ContourMatrix property
for contour objects.
Specifying irregularly spaced x and y vectors
is not the same as contouring irregularly spaced data. If x or y is
irregularly spaced, contourc calculates contours
using a regularly spaced contour grid, then transforms the data to x or y.