Graphics |
Drawing a Single Contour Line at a Desired Level
The contouring functions permit you to specify the number of contour levels or the particular contour levels to draw. In the case of contour
, the two forms of the function are contour(Z,n)
and contour(Z,v)
. Z
is the data matrix, n
is the number of contour lines, and v
is a vector of specific contour levels.
MATLAB does not differentiate between a scalar and a one-element vector. So, if v
is a one-element vector specifying a single contour at that level, contour
interprets it as the number of contour lines, not the contour level. Consequently, contour(Z,v)
behaves in the same manner as contour(Z,n)
.
To display a single contour line, define v
as a two-element vector with both elements equal to the desired contour level. For example, create a 3-D contour of the peaks
function.
xrange = -3:.125:3; yrange = xrange; [X,Y] = meshgrid(xrange,yrange); Z = peaks(X,Y); contour3(X,Y,Z)
To display only one contour level at Z = 1
, define v
as [1 1]
.
Filled Contours | The Contouring Algorithm |
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