Matlab: Kegel/Pfeil in 3D

Kegel/Pfeil in 3D

(English) Um einen Kegel bzw. ein Pfeil im 3D darzustellen kann die Funktion:

function arrow3D(startVec, stopVec, varargin)

Die Variable startVec ist der Anfang des 3D-Kegels und die Variable stopVec das Ende des Kegels. Du kannst die optionalen Argumente wie "Color", "Thickness" und "Length" verwenden, um den Kegel anzupassen.

Source code:

function arrow3D(startVec,stopVec,varargin)

% Input arguments:

% startVec ... input vector of the beginning of the point in [x,y,z]

% stopVec ... input vector of the ending of the point in [x,y,z]

%

% Optional input argument (varargin):

% 'Color',color ... define the color of the arrow/point

% 'Thickness',thick ... thickness of the arrow

% 'Length',length ... Length of the arrow

% 'Axes',ax ... Input axes

    if isempty(varargin)

        varargin{1} = '';

    end

    

    [x] = startVec(1); 

    [y] = startVec(2); 

    [z] = startVec(3); 

    x2 = stopVec(1);

    y2 = stopVec(2);

    z2 = stopVec(3);

    

    [logic, index] = max(strcmp(varargin,'Length'));

    if logic

        length = varargin{index+1};

    else

        length = mean(abs(stopVec-startVec))/10;

    end

    

    [logic, index] = max(strcmp(varargin,'Axes'));

    if logic

        ax = varargin{index+1};

    else

        ax = gca;

    end

    

    [logic, index] = max(strcmp(varargin,'Thickness'));

    if logic

        thick = varargin{index+1};

    else

        thick = mean(abs(stopVec-startVec))/10;

    end

    

    [logic, index] = max(strcmp(varargin,'Color'));

    if logic

        color = varargin{index+1};

    else

        color = [0 0 0];

    end

    

    vector2=[x2;y2;z2];

    vector1=[x;y;z];

    vector21=[x2-x;y2-y;z2-z];

    u1=[x2-x;y2-y;z2-z];

    u1=1/norm(u1)*u1;

    u2=[1;0;0];

    val=u1(1,1);

    abstand=u1-val*u2;

    if abstand==zeros(3,1)

        u2=[0;1;0];

    end

    

    %Kreuzprodukt

    u3(1,1)=u1(2,1)*u2(3,1)-u1(3,1)*u2(2,1);

    u3(2,1)=u1(3,1)*u2(1,1)-u1(1,1)*u2(3,1);

    u3(3,1)=u1(1,1)*u2(2,1)-u1(2,1)*u2(1,1);

    u3=1/norm(u3)*u3;

    %

    u2(1,1)=u1(2,1)*u3(3,1)-u1(3,1)*u3(2,1);

    u2(2,1)=u1(3,1)*u3(1,1)-u1(1,1)*u3(3,1);

    u2(3,1)=u1(1,1)*u3(2,1)-u1(2,1)*u3(1,1);

    u2=1/norm(u2)*u2;

    %orthnormale vektoren

    v1=u2;

    v2=u3;

    step=pi/50;

    a = step:step:2*pi;

    er=vector2;

    Er=repmat(er,1,numel(a));

    zerx=(Er(1,:))';

    zery=(Er(2,:))';

    zerz=(Er(3,:))';

    vectorscale=(1-length)*vector21;

    grund=(v1*sin(a)+v2*cos(a))*norm(vector2'-vector1')/3*thick;

    VS=repmat(vectorscale+vector1,1,numel(a));

    grund=grund+VS;

    xspitz=[zerx';grund(1,:)];

    yspitz=[zery';grund(2,:)];

    zspitz=[zerz';grund(3,:)];

    xrep=reshape(xspitz,1,2*numel(a))';

    yrep=reshape(yspitz,1,2*numel(a))';

    zrep=reshape(zspitz,1,2*numel(a))';

    plot3(ax, xrep, yrep, zrep, 'Color', color);

end