% SurfacePlotExample
%-----------------------------------------------------------
% An example on how to plot using the surf function.
%
%-----------------------------------------------------------
% Johan Clausen
% Department of Civil Engineering
% Aalborg University
% December 2014
%-----------------------------------------------------------
clear all

%----- Input variables ------------------------------
height = 3 ; % Domain height
width = 7 ; % Domain width
nx = 20 ; % Number of points in the x-direction
ny = 15 ; % Number of points in the x-direction

xmin = -3 ; xmax = xmin + width ; % x limits
ymin = -1 ; ymax = ymin + height ; % y limits
%----------------------------------------------------

%----- Calculations ----------------------
X = linspace(xmin,xmax,nx) ; % Row vector of x coordinates
Y = linspace(ymin,ymax,ny) ; % Row vector of y coordinates
[Xgrid,Ygrid] = meshgrid(X,Y) ; % Forms matrices of x and y coordinates.
								% Try writing them out in the command window.
								
F = Xgrid.^2 - Xgrid.*Ygrid + Ygrid.^2 ; % Calculation of a function
%-----------------------------------------

%----- Plotting ----------------------------------------------------
figure(1) ; clf ; hold on ;
surf(X,Y,F) ;
xlabel('{\it x} [m]','fontname','times','fontsize',12) ;
ylabel('{\it y} [m]','fontname','times','fontsize',12) ;
title('Surf plot example','fontname','times','fontsize',12) ;
shading interp % Makes the interpolation colors smooth. Try commenting the line out and see the difference
colorbar % To hide the colorbar, simply comment out this line.
axis equal % Ensures the same scale of the horizontal and the vertical axes. Try commenting this line to see the difference
% if you do not want the coordinate axes displayed, uncomment the line below. Sometimes this is more pretty.
% axis off
%-------------------------------------------------------------------

%----- The end ------------------------------------------------------