Accelerating the pace of engineering and science

# ezsurfc

Combined surface and contour plotter

## Syntax

ezsurfc(f)
ezsurfc(f,domain)
ezsurfc(x,y,z)
ezsurfc(x,y,z,[smin,smax,tmin,tmax])
ezsurfc(x,y,z,[min,max])
ezsurfc(...,n)
ezsurfc(...,'circ')

## Description

ezsurfc(f) creates a graph of f(x,y), where f is a symbolic expression that represents a mathematical function of two variables, such as x and y.

The function f is plotted over the default domain –2π < x < 2π, –2π < y < 2π. MATLAB® software chooses the computational grid according to the amount of variation that occurs; if the function f is not defined (singular) for points on the grid, then these points are not plotted.

ezsurfc(f,domain) plots f 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).

If f 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.

ezsurfc(x,y,z) plots the parametric surface x = x(s,t), y = y(s,t), and z = z(s,t) over the square –2π < s < 2π, –2π < t < 2π.

ezsurfc(x,y,z,[smin,smax,tmin,tmax]) or ezsurfc(x,y,z,[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.

## Examples

Create a surface/contour plot of the expression,

$f\left(x,y\right)=\frac{y}{1+{x}^{2}+{y}^{2}},$

over the domain –5 < x < 5, –2π < y < 2π, with a computational grid of size 35-by-35. Use the mouse to rotate the axes to better observe the contour lines (this picture uses a view of azimuth = -65 and elevation = 26).

```syms x y
ezsurfc(y/(1 + x^2 + y^2),[-5,5,-2*pi,2*pi],35)
```