# ezsurfc

Easy-to-use combination surface/contour plotter

## Syntax

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

## Description

ezsurfc(fun) creates a graph of fun(x,y) using the surfc function. The function fun is plotted over the default domain: -2π < x < 2π, -2π < y < 2π.

fun can be a function handle or a string (see the Tips section).

ezsurfc(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).

ezsurfc(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.

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

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

ezsurfc(...,'circ') plots f over a disk centered on the domain.

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

h = ezsurfc(...) returns the handles to the graphics objects in h.

## Examples

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### Surface and Contour Plot of Mathematical Function

Create a surface/contour plot of the expression over the domain and with a computational grid size of 35-by-35.

ezsurfc('sqrt(x^2 + y^2)',[-5,5,-2*pi,2*pi],35) 

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### Tips

ezsurf and ezsurfc do not accept complex inputs.

### Passing the Function as a String

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

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

is written as

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

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

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, ezsurfc('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 ezsurfc.

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

Note that when using function handles, you must use the array power, array multiplication, and array division operators (.^, .*, ./) since ezsurfc 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,k1,k2,k3) z = x.*(y.^k1)./(x.^k2 + y.^k3);

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

ezsurfc(@(x,y)myfun(x,y,2,2,4))