How can i pass S-curve through the center of a circle ??

hello coders, i need help for which i shall remain tahnkful.

I have an S-curve which i want to pass through the centers of the ellipse and circle ??

can any one guide me !! Please... the code is attached below.... thankyou

t1 = (0:pi/100:pi);  % Top curve 0 to 180 deg
t2 = (-pi:pi/100:0); % Bottom curve 180 to -180 deg

%%%  ellipse %%% 
xxCenter = 0*0.001;
yyCenter = -90*0.001;
xxRadius = 100*0.001;
yyRadius = 10*0.001;
zzCenter = 0*0.001;
zzRadius = 0*0.001;
xx = (xxRadius * cos(t1) + xxCenter).';
yy = (yyRadius * sin(t1) + yyCenter).';
zz = (zzRadius * sin(t1) + zzCenter).';

theta1 = 0:0.01:pi;
xx1Center = 0*0.001;
yy1Center = -90*0.001;
xx1Radius = 100*0.001;
yy1Radius = 61*0.001;
zz1Center = 0*0.001;
zz1Radius = 0*0.001;
xx1 = (xx1Radius * cos(-t1) + xx1Center).';
yy1 = (yy1Radius * sin(-t1) + yy1Center).';
zz1 = (zz1Radius * sin(-t1) + zz1Center).';

%%% Circle %%%   
semimajright6 = 142*0.001; %%% semi major axis %%% width, x-axis
semimajleft6 = 142*0.001; %%% semi major axis %%% width, x-axis
semiminup6 = 142*0.001; %%% semi minor axis %%% height, y-axis
semimindown6 = 142*0.001;  %%% semi minor axis %%% height, y-axis
n1st6up = 0;%%% controls the slope %%%  
m1st6up = 0; %%% controls the slope %%%  
n1st6down = 0; %%% controls the slope %%%
m1st6down = 0;  %%% controls the slope %%%

x6up = zeros(length(t1),length(n1st6up));
y6up = x6up;
z6up = x6up*0+1400*0.001;
leg6up = cell(length(n1st6up),1);

x6down = zeros(length(t2),length(n1st6down));
y6down = x6down;
z6down = x6down*0+1400*0.001;
leg6down = cell(length(n1st6down),1);

for i=1:length(n1st6up)
    x6up(:,i) = sign(cos(t1)).*semimajright6.*abs(cos(t1));
    y6up(:,i) = sign(sin(t1)).*semiminup6.*abs(sin(t1));
    leg(i) = {['n1st6up = ',num2str(n1st6up(i))]};
end

for i=1:length(n1st6down)
    
    x6down(:,i) = sign(cos(t2)).*semimajleft6.*abs(cos(t2));
    y6down(:,i) = sign(sin(t2)).*semimindown6.*abs(sin(t2));
    leg(i) = {['n1st6down = ',num2str(n1st6down(i))]};
end 

%%%  S-Curve %%%
x = 0:0.01:1.4;
y = smf(x,[0 1.4]);
% plot(x,y)
% hold on

%%%  Plot %%% 
% grid on
% hold on
% axis equal
% set(gcf,'color','white') 
% xlabel('X-axis','fontweight','bold','fontsize',10)
% ylabel('Y-axis','fontweight','bold','fontsize',10)
% zlabel('Z-axis','fontweight','bold','fontsize',10)
% hold on
% plot3(zz,xx,yy,'r',zz1,xx1,yy1,'r', z6up,x6up,y6up+(0.350),'r',z6down,x6down,y6down+(0.350),'r','linewidth',2)

%% ------- Code added by Sam Chak ------- 
plot3(zz,     xx,     yy,             'r'), hold on
plot3(zz1,    xx1,    yy1,            'r')
plot3(z6up,   x6up,   y6up+(0.350),   'r')
plot3(z6down, x6down, y6down+(0.350), 'r')
plot(x, y, 'color', "#0072BD"), hold off
axis equal, grid on

[Sam Chak]

Hi @Dr Sohaib Khan

I made some modifications to the code by commenting out certain lines and adding a few lines to display the figure. Could you please review and confirm if the 3D line plot is correctly displayed as intended? This will greatly assist users in visualizing your desired outcome.

[Dr Sohaib Khan]

hey sam, many thanks for quick reply. yes the 3D line is correctly displayed but it has to pass through the center of the circle and ellipse... i am tryying to explore matlab lab finctions for this work.

Answer 1

[Sam Chak]

Hi @Dr Sohaib Khan

Check if the following is the desired 3D line plot?

t1 = (0:pi/100:pi);  % Top curve 0 to 180 deg
t2 = (-pi:pi/100:0); % Bottom curve 180 to -180 deg

%%%  ellipse %%% 
xxCenter = 0*0.001;
yyCenter = -90*0.001;
xxRadius = 100*0.001;
yyRadius = 10*0.001;
zzCenter = 0*0.001;
zzRadius = 0*0.001;
xx = (xxRadius * cos(t1) + xxCenter).';
yy = (yyRadius * sin(t1) + yyCenter).';
zz = (zzRadius * sin(t1) + zzCenter).';

theta1 = 0:0.01:pi;
xx1Center =   0*0.001;
yy1Center = -90*0.001;
xx1Radius = 100*0.001;
yy1Radius =  61*0.001;
zz1Center =   0*0.001;
zz1Radius =   0*0.001;
xx1 = (xx1Radius * cos(-t1) + xx1Center).';
yy1 = (yy1Radius * sin(-t1) + yy1Center).';
zz1 = (zz1Radius * sin(-t1) + zz1Center).';

%%% Circle %%%   
semimajright6 = 142*0.001; %%% semi major axis %%% width, x-axis
semimajleft6 = 142*0.001; %%% semi major axis %%% width, x-axis
semiminup6 = 142*0.001; %%% semi minor axis %%% height, y-axis
semimindown6 = 142*0.001;  %%% semi minor axis %%% height, y-axis
n1st6up = 0;%%% controls the slope %%%  
m1st6up = 0; %%% controls the slope %%%  
n1st6down = 0; %%% controls the slope %%%
m1st6down = 0;  %%% controls the slope %%%

x6up = zeros(length(t1),length(n1st6up));
y6up = x6up;
z6up = x6up*0+1400*0.001;
leg6up = cell(length(n1st6up),1);

x6down = zeros(length(t2),length(n1st6down));
y6down = x6down;
z6down = x6down*0+1400*0.001;
leg6down = cell(length(n1st6down),1);

for i=1:length(n1st6up)
    x6up(:,i) = sign(cos(t1)).*semimajright6.*abs(cos(t1));
    y6up(:,i) = sign(sin(t1)).*semiminup6.*abs(sin(t1));
    leg(i) = {['n1st6up = ',num2str(n1st6up(i))]};
end

for i=1:length(n1st6down)
    x6down(:,i) = sign(cos(t2)).*semimajleft6.*abs(cos(t2));
    y6down(:,i) = sign(sin(t2)).*semimindown6.*abs(sin(t2));
    leg(i) = {['n1st6down = ',num2str(n1st6down(i))]};
end 

%%%  S-Curve (plotting on X–Z plane) %%%
x = 0:0.01:1.4;                                         % no change
y = zeros(1, numel(x));                                 % a bunch of zeros
CcenterZ =  0.35;                                       % center of circle  on Z-axis
EcenterZ = -0.10;                                       % center of ellipse on Z-axis
z = (CcenterZ - EcenterZ)*smf(x,[0 1.4]) + EcenterZ;    % rescale the S-curve

%%%  Plot %%%
%% ------- Code added by Sam Chak ------- 
plot3(zz,     xx,     yy,             'r'), hold on
plot3(zz1,    xx1,    yy1,            'r')
plot3(z6up,   x6up,   y6up+(0.350),   'r')
plot3(z6down, x6down, y6down+(0.350), 'r')
plot3(x, y, z, 'color', "#0072BD", 'linewidth', 2), hold off
axis equal, grid on, view(-65, 10)
xlabel x, ylabel y, zlabel z

[Dr Sohaib Khan]

THANKS A MILLION SAM !!! U ROCK !!!!

Big fat thankyou..... u solved it for me :) stay blessed !!!!

[Sam Chak]

You're welcome, @Dr Sohaib Khan.