MATLAB Function Reference |
Syntax
Description
ezcontour(fun)
plots the contour lines of fun(x,y)
using the contour
function. fun
is plotted over the default domain: -2 < x < 2, -2 < y < 2.
fun
can be a function handle for an M-file function or an anonymous function (see Function Handles and Anonymous Functions) or a string (see the Remarks section).
ezcontour(fun,domain)
plots fun(x,y)
over the specified domain
. domain
can be either a 4-by-1 vector [xmin
, xmax
, ymin
, ymax
] or a 2-by-1 vector [min
, max
] (where min
< x < max
, min
< y < max
).
ezcontour(...,n)
plots fun
over the default domain using an n
-by-n
grid. The default value for n
is 60.
ezcontour(axes_handle,...)
plots into the axes with handle axes_handle
instead of the current axes (gca
).
h = ezcontour(...)
returns the handles to contour objects in h
.
ezcontour
automatically adds a title and axis labels.
Passing the Function as a String
Array multiplication, division, and exponentiation are always implied in the string expression you pass to ezcontour
. For example, the MATLAB syntax for a contour plot of the expression
That is, x^2
is interpreted as x.^2
in the string you pass to ezcontour
.
If the function to be plotted is a function of the variables u and v (rather than x and y), then the domain endpoints umin
, umax
, vmin
, and vmax
are sorted alphabetically. Thus, ezcontour('u^2 - v^3',[0,1],[3,6])
plots the contour lines for u2 - v3 over 0 < u < 1, 3 < v < 6.
Passing a Function Handle
Function handle arguments must point to functions that use MATLAB syntax. For example, the following statements define an anonymous function and pass the function handle fh
to ezcontour
.
Note that when using function handles, you must use the array power, array multiplication, and array division operators (.^, .*, ./
) since ezcontour
does not alter the syntax, as in the case with string inputs.
Passing Additional Arguments
If your function has additional parameters, for example k
in myfun
:
then you can use an anonymous function to specify that parameter:
Examples
The following mathematical expression defines a function of two variables, x and y.
ezcontour
requires a function handle argument that expresses this function using MATLAB syntax. This example uses an anonymous function, which you can define in the command window without creating an M-File.
f=@(x,y) 3*(1-x).^2.*exp(-(x.^2) - (y+1).^2) ... - 10*(x/5 - x.^3 - y.^5).*exp(-x.^2-y.^2) ... - 1/3*exp(-(x+1).^2 - y.^2);
For convenience, this function is written on three lines. See the peaks
Pass the function handle f
to ezcontour
along with a domain ranging from -3 to 3 in both x
and y
and specify a computational grid of 49-by-49:
In this particular case, the title is too long to fit at the top of the graph, so MATLAB abbreviates the string.
See Also
contour
, ezcontourf
, ezmesh
, ezmeshc
, ezplot
, ezplot3
, ezpolar
, ezsurf
, ezsurfc
, function_handle
Contour Plots for related functions
eye | ezcontourf |
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