MATLAB^®

ezmeshc - Easy-to-use combination mesh/contour plotter

Syntax

ezmeshc(fun) ezmeshc(fun,domain) ezmeshc(funx,funy,funz) ezmeshc(funx,funy,funz,[smin,smax,tmin,tmax]) ezmeshc(funx,funy,funz,[min,max]) ezmeshc(...,n) ezmeshc(...,'circ') ezmesh(axes_handle,...) h = ezmeshc(...)

Description

ezmeshc(fun) creates a graph of fun(x,y) using the meshc function. fun is plotted over the default domain -2π < x < 2π, -2π < y < 2π.

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).

ezmeshc(fun,domain) plots fun 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).

ezmeshc(funx,funy,funz) plots the parametric surface funx(s,t), funy(s,t), and funz(s,t) over the square: -2π < s < 2π, -2π < t < 2π.

ezmeshc(funx,funy,funz,[smin,smax,tmin,tmax]) or ezmeshc(funx,funy,funz,[min,max]) plots the parametric surface using the specified domain.

ezmeshc(...,n) plots fun over the default domain using an n-by-n grid. The default value for n is 60.

ezmeshc(...,'circ') plots fun over a disk centered on the domain.

ezmesh(axes_handle,...) plots into the axes with handle axes_handle instead of the current axes (gca).

h = ezmeshc(...) returns the handle to a surface object in h.

Remarks

Passing the Function as a String

Array multiplication, division, and exponentiation are always implied in the string expression you pass to ezmeshc. For example, the MATLAB syntax for a mesh/contour plot of the expression

sqrt(x.^2 + y.^2);

is written as

ezmeshc('sqrt(x^2 + y^2)')

That is, x^2 is interpreted as x.^2 in the string you pass to ezmeshc.

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, ezmeshc('u^2 - v^3',[0,1],[3,6]) plots 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 ezmeshc.

fh = @(x,y) sqrt(x.^2 + y.^2);
ezmeshc(fh)

Note that when using function handles, you must use the array power, array multiplication, and array division operators (.^, .*, ./) since ezmeshc 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:

function z = myfun(x,y,k)
z = x.^k - y.^k - 1;

then you can use an anonymous function to specify that parameter:

ezmeshc(@(x,y)myfun(x,y,2))

Examples

Create a mesh/contour graph of the expression

over the domain -5 < x < 5, -2*pi < y < 2*pi:

ezmeshc('y/(1 + x^2 + y^2)',[-5,5,-2*pi,2*pi])

Use the mouse to rotate the axes to better observe the contour lines (this picture uses a view of azimuth = -65.5 and elevation = 26)