Surface

[u,v]=meshgrid(linspace(0,2*pi,250),linspace(-0.8,0.8,50));

t=1; %number of twist

surf(sin(u).*(2-v.*sin(t*u/2)),cos(u).*(2-v.*sin(t*u/2))...

,v.*cos(t*u/2),u...

,'edgecolor','none','facecolor',[0.5 0.5 0.5]);

lighting phong

material([0.4447 0.6154 0.7919])

camlight headlight

daspect([1 1 1])

[u,v]=meshgrid(-2:0.05:2,-0.8:0.05:0.8);

x= u.*v.^2 + 3*v.^4;

y= -2.*u.*v - 4*v.^3;

z= u;

surf(x,y,z...

,'facecolor',[0.5 0.76 0.1],'edgecolor','none');

lighting phong

camlight headlight,camlight left

material dull

axis off

daspect([1 1 1])

[u,v]=meshgrid(-2*pi:0.05:2*pi,-2*pi:0.05:pi);

A=0.5;B=1.5;C=1;

surf(A*cos(u),B*cos(v)+A*sin(u),C*sin(v)...

,'facecolor',[0.1 0.67 0.89],'edgecolor','none');

camlight headlight,camlight left,camlight(1,-90)

material metal

axis off

daspect([1 1 1])

numPoint=50;

z = cplxgrid(100);

x=real(z);

y=imag(z);

r=1.1*abs(z);

phi=angle(z);

n =5;

x=r.* cos(phi)-r.^(2*n - 1).*cos((2*n - 1)*phi)./(2*n - 1);

y=r.* sin(phi)+r.^(2*n - 1).*sin((2*n - 1)*phi)./(2*n - 1);

z=2*r.^n.*cos(n.*phi)./n;

surf(x,y,z,phi)

%code for outer tube

rth=linspace(0,2.01*pi,300);

rradi = 1.1*ones(1,300);

rx=rradi.* cos(rth)-rradi.^(2*n - 1).*cos((2*n - 1)*rth)./(2*n - 1);

ry=rradi.* sin(rth)+rradi.^(2*n - 1).*sin((2*n - 1)*rth)./(2*n - 1);

rz=2*rradi.^n.*cos(n.*rth)./n;

cmap = makeColorMap(rand(1,3),rand(1,3),rand(1,3),128);

shading interp

colormap([cmap ; flipud(cmap)]);

tubeLines = {[rx' ry' rz']};

daspect([1 1 1])

h=streamtube(tubeLines,0.2,[1 70]);

set(h,'edgecolor','none','facecolor',[0.8 0.8 0.8]);

axis equal

lighting phong

camlight headlight

axis off

[U,V]=meshgrid(linspace(-2*pi,2*pi,100));

x=(7+3*cos(V)).*cos(U);

y=(7+3*cos(V)).*sin(U);

z= 3*sin(V);

surf(x,y,z,'facelighting','phong','edgecolor','none','facecolor',[0.5 0.5 0.5]);

material([0.2259 0.5798 0.7604]);

camlight headlight,camlight left

axis off equal

[u,v]=meshgrid(-2*pi:0.05:2*pi,-2*pi:0.05:2*pi);

surf(cos(u).^3.*cos(v).^3,sin(u).^3.*cos(v).^3,sin(v).^3 ...

,'facecolor',[0.87 0.2 0.78],'edgecolor','none');

lighting phong

material(0.4447 0.6154 0.7919)

camlight headlight,camlight left

axis off

[u,v]=meshgrid(linspace(0,2*pi,250),linspace(-0.8,0.8,50));

t=4; %twist

surf(sin(u).*(2-v.*sin(t*u/2)),cos(u).*(2-v.*sin(t*u/2))...

,v.*cos(t*u/2),u...

,'edgecolor','none','facecolor',[0.5 0.5 0.5]);

lighting phong

material([0.4447 0.6154 0.7919])

camlight headlight

daspect([1 1 1])

[u,v]=meshgrid(linspace(0,2*pi,100),linspace(-5,4.4444,100));

x =v.^2.*sqrt((4-0.9.*v)./2).*cos(u);

y =v.^2.*sqrt((4-0.9.*v)./2).*sin(u);

z =v;

surf(x,y,z,z,'edgecolor','none','facecolor',[0.3 0.5 0.9]);

camlight headlight,camlight(1,-90)

material([0.7 0.4 0.6]);

daspect([1 1 0.1])

[x,y]=meshgrid(linspace(-5,5,100));

R=(x.*x+y.*y).^0.5;c=rand(1,3);

h=surf(x,y,1./(1+R).*(x.*sin(4*R)+y.*cos(4*R))...

,'facecolor',[0.4 0.7 0.8],'edgecolor','none');

lighting phong, camlight headlight,camlight left

material metal

axis off equal

[u,v]=meshgrid(-0.1:0.02:2*pi);

surf(cos(u).*(-1 + 3*cos(v))...

,sin(u).*( 1 + 3*cos(v))...

,1.3* sin(v)...

,'facecolor',rand(1,3),'edgecolor','none');

camlight headlight,camlight left

material metal

daspect([1 1 1])

[u,v]=meshgrid(-pi:0.03:pi,-pi:0.03:pi);

surf(u.*v.*sin(3*v),v,u.*v.*cos(3*v)...

,'facecolor',rand(1,3),'edgecolor','none');

camlight headlight,camlight left

material dull

%% Loxodrome

% Script to generate loxodrome

%

% $$u = [-3\pi\ 3\pi]$$

%

% $$v = [0\ 3\pi]$$

%

% $$a = 1$$

%

% $$b = \sqrt{1+(au)^2}$$

%

% $$x = {sin(u+v)}/b$$

%

% $$y = {cos(u+v)}/b$$

%

% $$z = {-au}/b$$

%

% Define the range

num_points = 150;

u = linspace (-3*pi,3*pi, num_points);

v = linspace (0, pi/3, num_points);

[U, V] = meshgrid (u, v);

% Calculate x,y,z coordinates

a = 1;

b = sqrt(1 + (a.*U).^2);

x = sin(U + V)./b;

y = cos(U + V)./b;

z = -a.*U./b;

[f,v]=surf2patch(x, y, z);

cmap=jet(4);

%% Draw loxodrome

% In each iteration,vertices are rotated by pi/2 and drawn.

% Doing this will give 4 surfaces.

for k=1:4

[xd,yd]=transform2d(v(:,1),v(:,2),0,0,pi/2,0,0);

v(:,1)=xd;

v(:,2)=yd;

h=patch('vertices',v,'faces',f,...

'facecolor',cmap(k,:),'FaceLighting','phong',...

'edgecolor','none','facevertexcdata',[0.8 0.7 0.1],...

'BackFaceLighting','reverselit');

end

%% View and material setting

material([0.1 0.6 0.5 20 0])

camlight

lighting phong

light('Position',[0.5 -10 0.2])

light('Position',[-10 2 0.2])

set(gcf,'position',[5 5 1200 700])

set(gcf,'Renderer','zbuffer');

axis equal on tight,view(3)

% If export_fig function is available then this will work.

callbackStr='export_fig(''png'',''loxo1'')';

sld2Hndl=uicontrol( ...

'Style','pushbutton', ...

'Position',[10 10 40 20], ...

'Callback',callbackStr);

p=2;

q=5;

t=linspace(0,2*p*pi,500);

x=(2+cos(q/p*t)).*cos(t);

y=(2+cos(q/p*t)).*sin(t);

z=sin(q/p*t);

verts = {[x' y' z']};

h=streamtube(verts,0.5);

set(h,'Facecolor',[0.6072 0.6299 0.3705],'edgecolor','none');

lighting phong

material dull

camlight headlight

axis off equal

view(3)

p=2;q=9;

p=4;q=3;