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如何在matlab中绘制地圈?_Matlab_Geometry_Surf - Fatal编程技术网

如何在matlab中绘制地圈?

如何在matlab中绘制地圈?,matlab,geometry,surf,Matlab,Geometry,Surf,如何在matlab中绘制地球球体 通过Geosphere我指的是球体上离散点的方式(Geosphere是,例如在3Ds Max中) 在下图中,它显示为球体(左侧)和地球球体(右侧) 在Matlab中有一个函数sphere,它给出了这样一个结果: 我需要得到这样一个地球圈的图像。我有一个矩阵Nx3,有地球圈每个点的xyz坐标 更新: 我只在显示(绘制)geosphere时遇到问题,因为我已经有了每个点的数据-xyz坐标。这就是为什么Gunther Struyf的回答帮助了我,我接受了 这是我通

如何在matlab中绘制地球球体

通过
Geosphere
我指的是球体上离散点的方式(Geosphere是,例如在3Ds Max中)

在下图中,它显示为
球体
(左侧)和
地球球体
(右侧)

在Matlab中有一个函数
sphere
,它给出了这样一个结果:

我需要得到这样一个地球圈的图像。我有一个矩阵Nx3,有地球圈每个点的xyz坐标

更新:

我只在显示(绘制)geosphere时遇到问题,因为我已经有了每个点的数据-xyz坐标。这就是为什么Gunther Struyf的回答帮助了我,我接受了

这是我通过这种方式得到的:(地球圈因子=6,N=362)

如何获取地球球体的三维点?我使用自由库来获取3d球体的点。(在库中有不同的离散化方法)


另外,对于计算地球圈的点,感谢下面的回答
@Rody Oldenhuis

如果您已经掌握了要点,我认为您可以使用与以下相同的解决方案:


我有一个函数,可以生成任意精度的球面三角剖分。这是我基于Giacari Luigi的
buildsphere
编写的一个函数,遗憾的是,Giacari Luigi已经完全从互联网上消失了(和这个函数一起)

所以,我会把它贴在这里,并在我的文件交换帐户上。一旦获得批准,我将用链接替换此代码

请注意,我的计算机上有一些预生成的模型,此函数依赖于这些模型。您必须先删除该节,然后才能运行它

绘制生成的球体:请参见Gunther Struyf的答案

function [p, t] = TriSphere(N, R)
% TRISPHERE: Returns the triangulated model of a sphere using the
% icosaedron subdivision method.
%
% INPUT:
% N (integer number) indicates the number of subdivisions,
%   it can assumes values between 0-inf. The greater N the better will look
%   the surface but the more time will be spent in surface costruction and
%   more triangles will be put in the output model.
%
% OUTPUT:
% In p (nx3) and t(mx3) we can find points and triangles indexes
% of the model. The sphere is supposed to be of unit radius and centered in
% (0,0,0). To obtain spheres centered in different location, or with
% different radius, is just necessary a traslation and a scaling
% trasformation. These operation are not perfomed by this code beacuse it is
% extrimely convinient, in order of time perfomances, to do this operation
% out of the function avoiding to call the costruction step each time.
%
% NOTE:
% This function is more efficient than the matlab command sphere in
% terms of dimension fo the model/ accuracy of recostruction. This due to
% well traingulated model that requires a minor number of patches for the
% same geometrical recostruction accuracy. Possible improvement are possible
% in time execution and model subdivision flexibilty.
%
% EXAMPLE:
%
%  N=5;
%
%  [p,t] = TriSphere(N);
%
%  figure(1) axis equal hold on trisurf(t,p(:,1),p(:,2),p(:,3)); axis vis3d
%  view(3)

% Author: Giaccari Luigi Created:25/04/2009%
% For info/bugs/questions/suggestions : giaccariluigi@msn.com
% ORIGINAL NAME: BUILDSPHERE
%
% Adjusted by Rody Oldenhuis (speed/readability)

    % error traps
    error(nargchk(1,1,nargin));
    error(nargoutchk(1,2,nargout));
    if ~isscalar(N)
        error('Buildsphere:N_mustbe_scalar',...
            'Input N must be a scalar.');
    end    
    if round(N) ~= N
        error('Buildsphere:N_mustbe_scalar',...
            'Input N must be an integer value.');
    end

    % Coordinates have been taken from Jon Leech' files

    % Twelve vertices of icosahedron on unit sphere
    tau = 0.8506508083520400; % t   = (1+sqrt(5))/2, tau = t/sqrt(1+t^2)
    one = 0.5257311121191336; % one = 1/sqrt(1+t^2)  (unit sphere)    
    p = [
        +tau  +one  +0     % ZA
        -tau  +one  +0     % ZB
        -tau  -one  +0     % ZC
        +tau  -one  +0     % ZD
        +one  +0    +tau   % YA
        +one  +0    -tau   % YB
        -one  +0    -tau   % YC
        -one  +0    +tau   % YD
        +0    +tau  +one   % XA
        +0    -tau  +one   % XB
        +0    -tau  -one   % XC
        +0    +tau  -one]; % XD

    % Structure for unit icosahedron
    t = [  
         5  8  9 
         5 10  8 
         6 12  7 
         6  7 11 
         1  4  5 
         1  6  4 
         3  2  8 
         3  7  2 
         9 12  1 
         9  2 12 
        10  4 11 
        10 11  3 
         9  1  5 
        12  6  1 
         5  4 10 
         6 11  4 
         8  2  9 
         7 12  2 
         8 10  3 
         7  3 11 ];

    % possible quick exit
    if N == 0, return, end

    % load pre-generated trispheres (up to 8 now...)
    if N <= 8
        S = load(['TriSphere', num2str(N), '.mat'],'pts','idx');
        p = S.pts; t = S.idx; 
        if nargin == 2, p = p*R; end
        return
    else
        % if even more is requested (why on Earth would you?!), make sure to START 
        % from the maximum pre-loadable trisphere
        S = load('TriSphere8.mat','pts','idx');
        p = S.pts; t = S.idx; clear S; N0 = 10;
    end

    % how many triangles/vertices do we have? 
    nt = size(t,1); np = size(p,1); totp = np;    
    % calculate the final number of points    
    for ii=N0:N, totp = 4*totp - 6; end    
    % initialize points array
    p = [p; zeros(totp-12, 3)];

    % determine the appropriate class for the triangulation indices
    numbits   = 2^ceil(log(log(totp+1)/log(2))/log(2));
    castToInt = ['uint',num2str(numbits)];

    % issue warning when required
    if numbits > 64
        warning('TriSphere:too_many_notes',...
            ['Given number of iterations would require a %s class to accurately ',...
            'represent the triangulation indices. Using double instead; Expect ',...
            'strange results!']);
        castToInt = @double;
    else
        castToInt = str2func(castToInt);
    end

    % refine icosahedron N times
    for ii = N0:N
        % initialize inner loop
        told  = t;
        t = zeros(nt*4, 3);
        % Use sparse. Yes, its slower in a loop, but for N = 6 the size is
        % already ~10,000x10,000, growing by a factor of 4 with every
        % increasing N; its simply too memory intensive to use zeros().
        peMap = sparse(np,np); 
        ct    = 1;        
        % loop trough all old triangles        
        for j = 1:nt

            % some helper variables
            p1 = told(j,1);
            p2 = told(j,2);
            p3 = told(j,3);
            x1 = p(p1,1); x2 = p(p2,1); x3 = p(p3,1);
            y1 = p(p1,2); y2 = p(p2,2); y3 = p(p3,2);
            z1 = p(p1,3); z2 = p(p2,3); z3 = p(p3,3);

            % first edge
            % -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

            % preserve triangle orientation
            if p1 < p2, p1m = p1; p2m = p2; else p2m = p1; p1m = p2; end

            % If the point does not exist yet, calculate the new point            
            p4 = peMap(p1m,p2m);
            if p4 == 0
                np = np+1;
                p4 = np;
                peMap(p1m,p2m) = np;%#ok
                p(np,1) = (x1+x2)/2;
                p(np,2) = (y1+y2)/2; 
                p(np,3) = (z1+z2)/2;
            end

            % second edge
            % -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

            % preserve triangle orientation
            if p2 < p3; p2m = p2; p3m = p3; else p2m = p3; p3m = p2; end

            % If the point does not exist yet, calculate the new point
            p5 = peMap(p2m,p3m);
            if p5 == 0
                np = np+1;
                p5 = np;
                peMap(p2m,p3m) = np;%#ok
                p(np,1) = (x2+x3)/2; 
                p(np,2) = (y2+y3)/2; 
                p(np,3) = (z2+z3)/2;
            end

            % third edge
            % -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

            % preserve triangle orientation
            if p1 < p3; p1m = p1; p3m = p3; else p3m = p1; p1m = p3; end

            % If the point does not exist yet, calculate the new point            
            p6 = peMap(p1m,p3m);
            if p6 == 0
                np = np+1;
                p6 = np;
                peMap(p1m,p3m) = np;%#ok
                p(np,1) = (x1+x3)/2; 
                p(np,2) = (y1+y3)/2;
                p(np,3) = (z1+z3)/2;                
            end

            % allocate new triangles
            %   refine indexing
            %          p1
            %          /\
            %         /t1\
            %      p6/____\p4
            %       /\    /\
            %      /t4\t2/t3\
            %     /____\/____\
            %    p3    p5     p2            
            t(ct,1) = p1; t(ct,2) = p4; t(ct,3) = p6; ct = ct+1;            
            t(ct,1) = p4; t(ct,2) = p5; t(ct,3) = p6; ct = ct+1;
            t(ct,1) = p4; t(ct,2) = p2; t(ct,3) = p5; ct = ct+1;            
            t(ct,1) = p6; t(ct,2) = p5; t(ct,3) = p3; ct = ct+1;

        end % end subloop
        % update number of triangles
        nt = ct-1;         
    end % end main loop

    % normalize all points to 1 (or R)
    p = bsxfun(@rdivide, p, sqrt(sum(p.^2,2)));
    if (nargin == 2), p = p*R; end
    % convert t to proper integer class
    t = castToInt(t);    

end % funciton TriSphere
函数[p,t]=三球体(N,R)
%TRISPHERE:返回使用
%二十面体细分法。
%
%输入:
%N(整数)表示细分的数量,
%它可以假定值在0-inf之间。N越大,效果越好
%但是,更多的时间将花在表面施工和维护上
%将在输出模型中放置更多三角形。
%
%输出:
%在p(nx3)和t(mx3)中,我们可以找到点和三角形索引
%这是模型的一部分。球体应具有单位半径,并以
% (0,0,0). 获取位于不同位置中心的球体,或使用
%不同的半径,只是需要一个平移和缩放
%转换。这些操作不是由该代码执行的,因为它是
%按照时间性能的顺序,非常方便地执行此操作
%函数外避免每次调用构造步骤。
%
%注:
%此函数比中的matlab命令球体更有效
%模型尺寸术语/重建精度。这是由于
%受良好训练的模型,该模型需要少量的修补程序
%同样的几何重构精度。可能的改进是可能的
%实时执行和模型细分灵活性。
%
%例如:
%
%N=5;
%
%[p,t]=三球(N);
%
%图(1)三曲面上的轴相等保持(t,p(:,1),p(:,2),p(:,3));三维轴
%视图(3)
%作者:Giacari Luigi创作:25/04/2009%
%有关信息/错误/问题/建议:giaccariluigi@msn.com
%原名:BUILDSPHERE
%
%由Rody Oldenhuis调整(速度/可读性)
%错误陷阱
错误(nargchk(1,1,nargin));
错误(nargoutchk(1,2,nargout));
如果~isscalar(N)
错误('Buildsphere:N\u必须是\u标量',。。。
“输入N必须是标量。”);
结束
如果是圆形(N)~=N
错误('Buildsphere:N\u必须是\u标量',。。。
“输入N必须是整数值。”);
结束
%坐标取自Jon Leech的档案
%单位球面上二十面体的十二个顶点
tau=0.850650883520400;%t=(1+sqrt(5))/2,tau=t/sqrt(1+t^2)
一=0.5257311121191336;%1=1/sqrt(1+t^2)(单位球面)
p=[
+tau+1+0%ZA
-tau+1+0%ZB
-τ-1+0%ZC
+τ-1+0%ZD
+1+0+tau%YA
+1+0-τ%YB
-1+0-τ%YC
-1+0+tau%YD
+0+tau+1%XA
+0-tau+1%XB
+0-tau-1%XC
+0+tau-1];%除息的
%单位二十面体的结构
t=[
5  8  9 
5 10  8 
6 12  7 
6  7 11 
1  4  5 
1  6  4 
3  2  8 
3  7  2 
9 12  1 
9  2 12 
10  4 11 
10 11  3 
9  1  5 
12  6  1 
5  4 10 
6 11  4 
8  2  9 
7 12  2 
8 10  3 
7  3 11 ];
%可能的快速退出
如果N==0,返回,结束
%加载预生成的三球体(现在最多8个…)
如果N 64
警告('TriSphere:注释太多',。。。
[“给定的迭代次数将需要%s类才能准确执行”,。。。
'表示三角剖分索引。改为使用double;Expect',。。。
“奇怪的结果!”);
castToInt=@double;
其他的
castToInt=str2func(castToInt);
结束
%细化二十面体N次
对于ii=N0:N
%初始化内部循环
t=t;
t=零(nt*4,3);
%使用稀疏。是的,它在循环中较慢,但对于N=6,大小为
%已经~10000x1000,每增加一次增长4倍
%增加氮;它的内存太大,无法使用零()。
peMap=稀疏(np,np);
ct=1;
%通过所有旧三角形循环
对于j=1:nt
%一些辅助变量
p1=已知(j,1);
p2=已知(j,2);
p3=已告知(j,3);
x1=p(p1,1);x2=p(p2,1);x3=p(p3,1);
y1=p(p1,2);y2=p(p2,2);y3=p(p3,2);
z1=p(p1,3);z2
function [p, t] = TriSphere(N, R)
% TRISPHERE: Returns the triangulated model of a sphere using the
% icosaedron subdivision method.
%
% INPUT:
% N (integer number) indicates the number of subdivisions,
%   it can assumes values between 0-inf. The greater N the better will look
%   the surface but the more time will be spent in surface costruction and
%   more triangles will be put in the output model.
%
% OUTPUT:
% In p (nx3) and t(mx3) we can find points and triangles indexes
% of the model. The sphere is supposed to be of unit radius and centered in
% (0,0,0). To obtain spheres centered in different location, or with
% different radius, is just necessary a traslation and a scaling
% trasformation. These operation are not perfomed by this code beacuse it is
% extrimely convinient, in order of time perfomances, to do this operation
% out of the function avoiding to call the costruction step each time.
%
% NOTE:
% This function is more efficient than the matlab command sphere in
% terms of dimension fo the model/ accuracy of recostruction. This due to
% well traingulated model that requires a minor number of patches for the
% same geometrical recostruction accuracy. Possible improvement are possible
% in time execution and model subdivision flexibilty.
%
% EXAMPLE:
%
%  N=5;
%
%  [p,t] = TriSphere(N);
%
%  figure(1) axis equal hold on trisurf(t,p(:,1),p(:,2),p(:,3)); axis vis3d
%  view(3)

% Author: Giaccari Luigi Created:25/04/2009%
% For info/bugs/questions/suggestions : giaccariluigi@msn.com
% ORIGINAL NAME: BUILDSPHERE
%
% Adjusted by Rody Oldenhuis (speed/readability)

    % error traps
    error(nargchk(1,1,nargin));
    error(nargoutchk(1,2,nargout));
    if ~isscalar(N)
        error('Buildsphere:N_mustbe_scalar',...
            'Input N must be a scalar.');
    end    
    if round(N) ~= N
        error('Buildsphere:N_mustbe_scalar',...
            'Input N must be an integer value.');
    end

    % Coordinates have been taken from Jon Leech' files

    % Twelve vertices of icosahedron on unit sphere
    tau = 0.8506508083520400; % t   = (1+sqrt(5))/2, tau = t/sqrt(1+t^2)
    one = 0.5257311121191336; % one = 1/sqrt(1+t^2)  (unit sphere)    
    p = [
        +tau  +one  +0     % ZA
        -tau  +one  +0     % ZB
        -tau  -one  +0     % ZC
        +tau  -one  +0     % ZD
        +one  +0    +tau   % YA
        +one  +0    -tau   % YB
        -one  +0    -tau   % YC
        -one  +0    +tau   % YD
        +0    +tau  +one   % XA
        +0    -tau  +one   % XB
        +0    -tau  -one   % XC
        +0    +tau  -one]; % XD

    % Structure for unit icosahedron
    t = [  
         5  8  9 
         5 10  8 
         6 12  7 
         6  7 11 
         1  4  5 
         1  6  4 
         3  2  8 
         3  7  2 
         9 12  1 
         9  2 12 
        10  4 11 
        10 11  3 
         9  1  5 
        12  6  1 
         5  4 10 
         6 11  4 
         8  2  9 
         7 12  2 
         8 10  3 
         7  3 11 ];

    % possible quick exit
    if N == 0, return, end

    % load pre-generated trispheres (up to 8 now...)
    if N <= 8
        S = load(['TriSphere', num2str(N), '.mat'],'pts','idx');
        p = S.pts; t = S.idx; 
        if nargin == 2, p = p*R; end
        return
    else
        % if even more is requested (why on Earth would you?!), make sure to START 
        % from the maximum pre-loadable trisphere
        S = load('TriSphere8.mat','pts','idx');
        p = S.pts; t = S.idx; clear S; N0 = 10;
    end

    % how many triangles/vertices do we have? 
    nt = size(t,1); np = size(p,1); totp = np;    
    % calculate the final number of points    
    for ii=N0:N, totp = 4*totp - 6; end    
    % initialize points array
    p = [p; zeros(totp-12, 3)];

    % determine the appropriate class for the triangulation indices
    numbits   = 2^ceil(log(log(totp+1)/log(2))/log(2));
    castToInt = ['uint',num2str(numbits)];

    % issue warning when required
    if numbits > 64
        warning('TriSphere:too_many_notes',...
            ['Given number of iterations would require a %s class to accurately ',...
            'represent the triangulation indices. Using double instead; Expect ',...
            'strange results!']);
        castToInt = @double;
    else
        castToInt = str2func(castToInt);
    end

    % refine icosahedron N times
    for ii = N0:N
        % initialize inner loop
        told  = t;
        t = zeros(nt*4, 3);
        % Use sparse. Yes, its slower in a loop, but for N = 6 the size is
        % already ~10,000x10,000, growing by a factor of 4 with every
        % increasing N; its simply too memory intensive to use zeros().
        peMap = sparse(np,np); 
        ct    = 1;        
        % loop trough all old triangles        
        for j = 1:nt

            % some helper variables
            p1 = told(j,1);
            p2 = told(j,2);
            p3 = told(j,3);
            x1 = p(p1,1); x2 = p(p2,1); x3 = p(p3,1);
            y1 = p(p1,2); y2 = p(p2,2); y3 = p(p3,2);
            z1 = p(p1,3); z2 = p(p2,3); z3 = p(p3,3);

            % first edge
            % -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

            % preserve triangle orientation
            if p1 < p2, p1m = p1; p2m = p2; else p2m = p1; p1m = p2; end

            % If the point does not exist yet, calculate the new point            
            p4 = peMap(p1m,p2m);
            if p4 == 0
                np = np+1;
                p4 = np;
                peMap(p1m,p2m) = np;%#ok
                p(np,1) = (x1+x2)/2;
                p(np,2) = (y1+y2)/2; 
                p(np,3) = (z1+z2)/2;
            end

            % second edge
            % -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

            % preserve triangle orientation
            if p2 < p3; p2m = p2; p3m = p3; else p2m = p3; p3m = p2; end

            % If the point does not exist yet, calculate the new point
            p5 = peMap(p2m,p3m);
            if p5 == 0
                np = np+1;
                p5 = np;
                peMap(p2m,p3m) = np;%#ok
                p(np,1) = (x2+x3)/2; 
                p(np,2) = (y2+y3)/2; 
                p(np,3) = (z2+z3)/2;
            end

            % third edge
            % -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

            % preserve triangle orientation
            if p1 < p3; p1m = p1; p3m = p3; else p3m = p1; p1m = p3; end

            % If the point does not exist yet, calculate the new point            
            p6 = peMap(p1m,p3m);
            if p6 == 0
                np = np+1;
                p6 = np;
                peMap(p1m,p3m) = np;%#ok
                p(np,1) = (x1+x3)/2; 
                p(np,2) = (y1+y3)/2;
                p(np,3) = (z1+z3)/2;                
            end

            % allocate new triangles
            %   refine indexing
            %          p1
            %          /\
            %         /t1\
            %      p6/____\p4
            %       /\    /\
            %      /t4\t2/t3\
            %     /____\/____\
            %    p3    p5     p2            
            t(ct,1) = p1; t(ct,2) = p4; t(ct,3) = p6; ct = ct+1;            
            t(ct,1) = p4; t(ct,2) = p5; t(ct,3) = p6; ct = ct+1;
            t(ct,1) = p4; t(ct,2) = p2; t(ct,3) = p5; ct = ct+1;            
            t(ct,1) = p6; t(ct,2) = p5; t(ct,3) = p3; ct = ct+1;

        end % end subloop
        % update number of triangles
        nt = ct-1;         
    end % end main loop

    % normalize all points to 1 (or R)
    p = bsxfun(@rdivide, p, sqrt(sum(p.^2,2)));
    if (nargin == 2), p = p*R; end
    % convert t to proper integer class
    t = castToInt(t);    

end % funciton TriSphere