|
% Copyright 2015 The MathWorks, Inc.
|
|
% Last Edited: Sean de Wolski, 05/24/2013
|
|
|
|
function blockAvg(Nx,Ny,Nxavg,Nyavg)
|
|
%% Example 1
|
|
% Input values Nx, Ny = 1500, Nxavg, Nyavg = 25;
|
|
%
|
|
% Want to create a surface and look at it averaged over a
|
|
% a particular resolution
|
|
|
|
if ~nargin
|
|
Nx = 1500;
|
|
Ny = 1500;
|
|
Nxavg = 25;
|
|
Nyavg = 25;
|
|
end
|
|
|
|
%% Initial Parameter Values
|
|
|
|
tic
|
|
|
|
Lx = 10; % Length of x dimension
|
|
Ly = 10; % Length of y dimension
|
|
|
|
x = linspace(1,Lx,Nx); % Creating x vector
|
|
y = linspace(1,Ly,Ny); % Creating y vector
|
|
|
|
%% Setting up values of surface on grid
|
|
|
|
|
|
for i = 1:length(x)
|
|
for j = 1:length(y)
|
|
yp = y(j);
|
|
xp = x(i);
|
|
mysurf(i,j) = 5*cos((xp+yp)*2*pi)+...
|
|
2*sin(xp*2*pi)+2*cos(xp*2*pi);
|
|
end
|
|
end
|
|
|
|
%% Averaging values over the grid
|
|
|
|
for i = Nxavg:length(x)
|
|
for j = Nyavg:length(y)
|
|
if (mod(j,Nyavg)==0 && mod(i,Nxavg)==0)
|
|
|
|
idown = i-Nxavg+1;
|
|
jdown = j-Nyavg+1;
|
|
iup = i;
|
|
jup = j;
|
|
|
|
iavg = floor(i/Nxavg);
|
|
javg = floor(j/Nyavg);
|
|
|
|
mysurf_avg(iavg,javg) = ...
|
|
sum(sum(mysurf(idown:iup,jdown:jup)))/(Nxavg*Nyavg);
|
|
|
|
xavg(iavg) = (x(iup)+x(idown))/2;
|
|
yavg(javg) = (y(jup)+y(jdown))/2;
|
|
|
|
end
|
|
end
|
|
end
|
|
|
|
toc
|
|
|
|
%% Plotting the results to compare
|
|
|
|
ax(1) = subplot(2,1,1);
|
|
imagesc(x,y,mysurf);
|
|
title('Original Function');
|
|
axis off
|
|
|
|
ax(2) = subplot(2,1,2);
|
|
imagesc(xavg,yavg,mysurf_avg);
|
|
title('Averaged Function');
|
|
axis off
|
|
|
|
linkaxes(ax,'xy');
|
|
|