I want to draw a transparent sphere with three X Y Z and some curves inside it

I want to draw a transparent sphere of poincare with three X Y Z and some curves inside it

i did it with hand in the attached file

I need your help

thank you very much

Answer 1

[Dave B]

How about something like this (I'm including the code to draw some circles around the sphere, a couple of different ways, but I'll leave it to you to do the geometry):

[x,y,z]=sphere;
surf(x,y,z,'FaceAlpha',.3,'EdgeColor','none');
hold on
plot3(x(z==0),y(z==0),z(z==0),'k--','LineWidth',2)
[x2,y2,z2]=sph2cart(linspace(0,2*pi,100),-pi/7,1);
plot3(x2,y2,repelem(z2,100),'k--','LineWidth',2)
axis equal

[DGM]

Additionally, the projected section of the surface can be done in a manner similar to the circles. They're just four arcs.

[walid albugami]

Thank you very much Dave, but I'm not specialist in Matlab, do you tell me please how can i add the three axes X Y Z,

DGM, thank you for your comments but i dont know really how can i add this (P) points with their four arcs, Please if you can help me about it.

[Dave B]

Do you mean you want to add the lines eminating from the center? This makes them with a greyish color (and I turned off the default MATLAB axes visibility in the background:

[x,y,z]=sphere;
surf(x,y,z,'FaceAlpha',.3,'EdgeColor','none');
hold on
plot3(x(z==0),y(z==0),z(z==0),'k--','LineWidth',2)
[x2,y2,z2]=sph2cart(linspace(0,2*pi,100),-pi/7,1);
plot3(x2,y2,repelem(z2,100),'k--','LineWidth',2)
axis equal
plot([-1.5 1.5],[0 0],'-','LineWidth',2,'Color',[.5 .5 .5])
plot([0 0],[-1.5 1.5],'-','LineWidth',2,'Color',[.5 .5 .5])
plot3([0 0],[0 0],[-1.5 1.5],'-','LineWidth',2,'Color',[.5 .5 .5])
axis off

[DGM]

Here's more using Dave's example.

% plot the spherical shell with radius 1
[x,y,z]=sphere;
surf(x,y,z,'FaceAlpha',.3,'EdgeColor','none');
hold on

% plot equator
plot3(x(z==0),y(z==0),z(z==0),'k--','LineWidth',2)
% plot lower circle at -pi/7
[x2,y2,z2]=sph2cart(linspace(0,2*pi,100),-pi/7,1);
plot3(x2,y2,repelem(z2,100),'k--','LineWidth',2)

% plot axis lines with arrowheads
axlen = 1.5; % length of line
headlen = 0.1; % length of arrowhead
headwid = 0.15; % width of arrowhead
longaxis = [-1 1 1 1 1]*axlen - [0 0 1 0 1]*headlen;
broadaxis = [0 0 -0.5 0 0.5]*headwid;
offaxis = [0 0 0 0 0];
plot3(longaxis,broadaxis,offaxis,'-','LineWidth',2,'Color',[.5 .5 .5]) % x
plot3(broadaxis,longaxis,offaxis,'-','LineWidth',2,'Color',[.5 .5 .5]) % y
plot3(broadaxis,offaxis,longaxis,'-','LineWidth',2,'Color',[.5 .5 .5]) % z

% plot P
dalph = 0.08*pi;
deps = 0.08*pi;
P = [1.4*pi -0.1*pi 1];
[px py pz] = sph2cart(P(1),P(2),P(3));
plot3(px,py,pz,'b.','markersize',20)

% plot surface element boundary
[xl,yl,zl] = sph2cart(linspace(P(1),P(1)+2*dalph,10),P(2),1);
plot3(xl,yl,repelem(zl,10),'b:','LineWidth',2)
[xl,yl,zl] = sph2cart(linspace(P(1),P(1)+2*dalph,10),P(2)+2*deps,1);
plot3(xl,yl,repelem(zl,10),'b:','LineWidth',2)
[xl,yl,zl] = sph2cart(P(1),linspace(P(2),P(2)+2*deps,10),1);
plot3(xl,yl,zl,'b:','LineWidth',2)
[xl,yl,zl] = sph2cart(P(1)+2*dalph,linspace(P(2),P(2)+2*deps,10),1);
plot3(xl,yl,zl,'b:','LineWidth',2)

% plot ray from center to P
plot3([0 px],[0 py],[0 pz],'b','LineWidth',1.5)
% and so on

% place text on axes
text(axlen+0.1,0,0,'X','horizontalalignment','center')
text(0,axlen+0.1,0,'Y','horizontalalignment','center')
text(0,0,axlen+0.1,'Z','horizontalalignment','center')
% and so on

axis equal
axis off

[walid albugami]

Thank you very much DGM and Dave.

The last figure of DGM is almost what i need, but the position of X axe should be excatly what i drew in the attached file, other than that the bleu rectangle of DGM is wonderful but mising two (sides), and (the upper side should coincide with dotted line of the middle cercle) and the right side should be parallele to the plan (X-Z).

Best regards for both,

i consider very much your help.

[walid albugami]

the bottom side of the blue rectangle should coincide with the dotted line of the bottom cercle on the sphere

[DGM]

I intentionally didn't align the rectangle and left things incomplete because I'm not inclined to do everything. I'm providing examples of how the various elements can be constructed.

[walid albugami]

i tried to change some parameters before i sent my last comments but it didn't work with me, if you know juste tell me please only what i have to change and i will do it.

thank you very much