3d lines plot

Dear everybody,

I have a problem, I want to draw 3 line.

First line: In xy plan has to be sin(x) ;

Second line: In xz plan has to be cos(x) ;

Third line: In xyz plan has to be sin(x)+cos(x);

I have no idea for it. What is the solution?

I will appreciate your help.

Thank you.

Istvan

[Sam Chak]

Hi @Istvan, The first curve is , and the second curve is . But I cannot visualize the third curve on the so-called "x-y-z" plane. Can you sketch it?

[Istvan]

Hi @Sam Chak,

It would be an elliptically polar wave. in this picture the cos and sin function are replaced, but the point is the same.

Answer 1

[Star Strider]

Peerhaps something like this —

t = linspace(0, 1).';
x = sin(2*pi*t);
y = cos(2*pi*t);
z = x+y;

figure
plot3(x, y, z)
grid on
xlabel('X')
ylabel('Y')
zlabel('Z')
axis('equal')

figure
stem3(x, y, z, '.')
hold on
patch(x, y, zeros(size(z)), 'g', FaceAlpha=0.5)
hold off
grid on
xlabel('X')
ylabel('Y')
zlabel('Z')
axis('equal')

figure
patch(x, y, z, 'r', FaceAlpha=0.5)
hold on
patch(x, y, zeros(size(z)), 'g', FaceAlpha=0.5)
hold off
grid on
axis('equal')
xlabel('X')
ylabel('Y')
zlabel('Z')
view(-27, 30)

.

[Istvan]

Hi @Star Strider

Dear Sam,

It would be an elliptically polar wave. in this picture the cos and sin function are replaced, but the point is the same.

[Walter Roberson]

sin(x)+cos(x) does not get you an elliptic polar wave.

Something like sin(x)+cos(y) would be closer.

[Sam Chak]

But sin(x) + cos(y) would give a surface. Thus, I believe Star's parameterized equations is probably the best approach to generate the helical spiral trajectory (bolded black curve) that maps out the elliptical projection on the normal plane.

[Star Strider]

I didn’t realise what you wanted.

Try this —

t = linspace(0, 4, 500).';
x = sin(2*pi*t);
y = cos(2*pi*t);

figure
patch(t, x, zeros(numel(t), 1), 'r', FaceAlpha=0.5, EdgeColor='r')
hold on
patch(t, zeros(numel(t), 1), [0; y(2:end-1); 0], 'b', FaceAlpha=0.5, EdgeColor='b')
plot3(t, x, y, 'g', LineWidth=2)
plot3(xlim, [0 0], [0 0], '-k', LineWidth=2)
plot3([0 0], ylim, [0 0], '-k', LineWidth=2)
plot3([0 0], [0 0], zlim, '-k', LineWidth=2)
hold off
grid on
xlabel('X')
ylabel('Y')
zlabel('Z')
text(0, 0, max(zlim), 'Y', Vert='bottom', Horiz='center')
text(0, min(ylim)-0.3, 0, 'Z', Horiz='left')
text(4.1, 0, 0, 'X', Horiz='left')
view(25,20)
Ax = gca;
Ax.Visible = 'off';
axis('equal')

●

Make appropriate changes to get the result you want.

.

[Istvan]

@Star Strider Perfect, that is exatly what i thought.

I am grateful to you.

Thank you.

Best regards.

[Star Strider]

My pleasure!

If my Answer helped you solve your problem, please Accept it!

.