%rbwavescont.m
%Create a 3D printable Plot of a continuous pattern from Red to Blue light EM waves
%Steven Sahyun October 30, 2015

clear;
clf();
center = 0;

%The x values here are setting the depth of the print.
lambda1 = 360; %blue wavelength in nm; ideally start at 400, but need to account for border.
lambda2 = 740; %red wavelength in nm; ideally start at 700, but need to account for border.

k1 = 2*pi/lambda1;
k2 = 2*pi/lambda2;

xplotwidth = 1600;
xmin = center;
xmax = center+xplotwidth;
xstep = (xmax-xmin)/100; %100 data points
x = xmin:xstep:xmax;

x0 = 0*x+1;

%Change these y values to affect the shape of the graph. You can change the
%begining and end points for "plotting" by changing ymin and ymax.
yplotwidth = 10;
ymin = center-yplotwidth; %Change the start point in terms of # of standard deviations
ymax = center+yplotwidth; %Change the end point in terms of # of standard deviations
ystep = (ymax-ymin)/100; %100 data points
y = ymin:ystep:ymax;

y0 = 0*y+1;


meshgrid(x,y);

zscale = 0.5;
offset = 0.55;

z = y0'*x0;

%make the wave patterns
%need 100 values of k
dlambda = (lambda2 - lambda1);
lambdastepmax = 100;

for lambdastep = 1:lambdastepmax
    lambda = lambdastep*dlambda/lambdastepmax+lambda1;%go from lambda1 to lambda2 in 100 steps of size dlambda
    k = 2*pi/lambda;
    A = y0'*sin(k*x-pi/2)*zscale+offset;
    z(lambdastep,:)=A(lambdastep,:);
end

%Provide a border with height of 0 that is 10 rows wide.
%get size of z, m = rows, n=columns
[m, n] = size(z);
z(1:10, :) = 0;
z(n-10:n, :) = 0;


%Plot the surface
surf(x,y,z);
axis([xmin, xmax, ymin, ymax, 0, zscale+offset])

%Convert to a 3D printable file; You need to have stlwrite.m and surf2solid.m by
%Sven Holcombe in the same directory as this file.
%See: http://jmumakerlab.blogspot.com/2013/11/exporting-stl-from-matlab.html
% http://www.mathworks.com/matlabcentral/fileexchange/42876-surf2solid-make-a-solid-volume-from-a-surface-for-3d-printing
% http://www.mathworks.com/matlabcentral/fileexchange/20922-stlwrite-filename--varargin-

%minz = 0;
%maxz = zscale;
%c=255*((z+minz)/maxz);


%For getting the 3D print to work out
xscale = 0.05;
yscale = 3;
zscale = 10;


WaveSurfaceRBcont = surf2solid(x*xscale, y*yscale, z*zscale, 'ELEVATION', -1); %Can change Elevation for a thicker base.
stlwrite('WaveSurfaceRBcontstl.stl',WaveSurfaceRBcont)