Points which are inside a cone

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yogesh jain 2015-12-13

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评论： yogesh jain 2015-12-16

Hello all, I have a query , I have a cone and I know its R and H . I also know the outer points of the cone .How I can get all points which lie inside the cone and describes the cone . thank you

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John D'Errico 2015-12-13

编辑：John D'Errico 2015-12-13

There are infinitely many points inside a cone, or any non-degenerate volume.

yogesh jain 2015-12-14

Ya , those are many . But some of them which can tend to make a solid cone . I know the starting and ending points of the cone . thank you

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Walter Roberson 2015-12-13

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https://ww2.mathworks.cn/matlabcentral/answers/260137-points-which-are-inside-a-cone#answer_203118

http://uk.mathworks.com/matlabcentral/answers/257208-how-to-get-points-inside-a-cone#comment_325438

When an object is symmetric around one axis, then rotating around the axis produces a result identical to the original. Therefor your "dependent on x,y,z and az-el only" is really describing a cone at an arbitrary location and orientation in space, not a restricted case at all.

yogesh jain 2015-12-16

在 MATLAB Online 中打开

yes sir , that is true . But when I am rotating the points around any of the axis it is not showing them precisely . I used these -

 r=5 ; h=20;
x1=2 ; x2 =20 ; y1=3 ; y2 =3 ; z1=12; z2 = 12;
xvec = floor(-r+x1):ceil(r+x1);
yvec = xvec;
hvec = 0:ceil(h);
[X, Y, H] = ndgrid(xvec, yvec,0:floor(h));
r_at_H = r * (1 - H/h);
is_in_cone = abs(X) <= r & abs(Y) <= r & H <= h & sqrt(X.^2+Y.^2) <= r_at_H;
Xc = X(is_in_cone);
Yc = Y(is_in_cone);
Hc = H(is_in_cone);
Xc1=Xc+20.3;
Yc1=Yc+10.5;
Hc1=Hc+12.7;
 A(:,1)=Xc1;
A(:,2)=Yc1;
A(:,3)=Hc1;
B=ceil(A);
 theta=45;
rad=degtorad(theta);
C=B*[1,0,0 ; 0,cos(rad),sin(rad) ; 0,sin(rad),cos(rad)];         % X-plane
Xc2=C(:,1);
Yc2=C(:,2);
Hc2=C(:,3);
pointsize = 20;
scatter3(Xc2,Yc2,Hc2, pointsize, 'filled');