ezmesh

Easy to use 3-D mesh plotter

Syntax

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

Description

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

The function f is plotted over the default domain: -2 < x < src="http://www.physiol.ox.ac.uk/Computing/Online_Documentation/Matlab/techdoc/ref/pi.gif" align="bottom">, -2 < y < src="http://www.physiol.ox.ac.uk/Computing/Online_Documentation/Matlab/techdoc/ref/pi.gif" align="bottom">. MATLAB 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.

ezmesh(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 <>y <>

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, ezmesh('u^2 - v^3',[0,1],[3,6]) plots u² - v³ over 0 < u <>v <>

ezmesh(x,y,z) plots the parametric surface x = x(s,t), y = y(s,t), and z = z(s,t) over the square: -2 < s < src="http://www.physiol.ox.ac.uk/Computing/Online_Documentation/Matlab/techdoc/ref/pi.gif" align="bottom">, -2 < t < src="http://www.physiol.ox.ac.uk/Computing/Online_Documentation/Matlab/techdoc/ref/pi.gif" align="bottom">.

ezmesh(x,y,z,[smin,smax,tmin,tmax]) or ezmesh(x,y,z,[min,max]) plots the parametric surface using the specified domain.

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

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

Remarks

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

• sqrt(x.^2 + y.^2);
  
  

is written as:

• ezmesh('sqrt(x^2 + y^2)')
  
  

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

Examples

This example visualizes the function,

• 

with a mesh plot drawn on a 40-by-40 grid. The mesh lines are set to a uniform blue color by setting the colormap to a single color:

• ezmesh('x*exp(-x^2-y^2)',40)
  
  colormap([0 0 1])
  
  
  
  
  
  
  
  

ezmeshc



Easy to use combination mesh/contour plotter

Syntax

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

Description

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

The function f is plotted over the default domain: -2 < x < src="http://www.physiol.ox.ac.uk/Computing/Online_Documentation/Matlab/techdoc/ref/pi.gif" align="bottom">, -2 < y < src="http://www.physiol.ox.ac.uk/Computing/Online_Documentation/Matlab/techdoc/ref/pi.gif" align="bottom">. MATLAB 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.

ezmeshc(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 <>y <>

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, ezmeshc('u^2 - v^3',[0,1],[3,6]) plots u² - v³ over 0 < u <>v <>

ezmeshc(x,y,z) plots the parametric surface x = x(s,t), y = y(s,t), and z = z(s,t) over the square: -2 < s < src="http://www.physiol.ox.ac.uk/Computing/Online_Documentation/Matlab/techdoc/ref/pi.gif" align="bottom">, -2 < t < src="http://www.physiol.ox.ac.uk/Computing/Online_Documentation/Matlab/techdoc/ref/pi.gif" align="bottom">.

ezmeshc(x,y,z,[smin,smax,tmin,tmax]) or ezmeshc(x,y,z,[min,max]) plots the parametric surface using the specified domain.

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

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

Remarks

Array multiplication, division, and exponentiation are always implied in the 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.

Examples

Create a mesh/contour graph of the expression,

• 

over the domain -5 < x <>y <>

• 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).