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如何在Matlab中用圆而不是直线轴绘图？

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我有一组3个数据集，我想在MATLAB中绘制，但是'x'轴，我想以圆形而不是直底线形式给出 . 有什么想法怎么做？

一个示例图：

alt text http://img526.imageshack.us/img526/5420/busvoltageplot.jpg

在MATLAB中绘制的正常命令是 plot(x, data1, x data2, x, data3) ，其中x轴被视为直线 . 我希望x轴取圆圈 . 有没有人知道它的命令 .

matlab plot polar-coordinates

4 回答

  • 4

    @Alok问你是否想要一个极地情节 . 我告诉你，你确实想要一个极地情节！有关函数 polar() 及其关系，请参阅Matlab文档，例如 cart2pol . 根据您的具体要求（我没有按照您的链接），您可能会发现准确生成您想要的图表相对容易或相当困难 .

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  • 1

    以下是一个完整示例，说明如何将数据从线轴映射到圆 .

    我展示了实现目标的两种方法：

    • 三个数据系列重叠的地方（即全部映射到相同范围）

    • 另一种选择是叠加它们（在不同的相邻范围内）

    基本思路：如果你有一个系列 D ，那么将点映射到一个圆，其中半径等于数据的值，使用：

    theta = linspace(0, 2*pi, N);    %# divide circle by N points (length of data)
r = data;                        %# radius
x = r.*cos(theta);               %# x-coordinate
y = r.*sin(theta);               %# y-coordinate
plot(x, y, '-');

    选项1

    %# some random data
K = 3;
N = 30;
data = zeros(K,N);
data(1,:) = 0.2*randn(1,N) + 1;
data(2,:) = 0.2*randn(1,N) + 2;
data(3,:) = 0.2*randn(1,N) + 3;

center = [0 0];                        %# center (shift)
radius = [data data(:,1)];             %# added first to last to create closed loop
radius = normalize(radius',1)'+1;      %# normalize data to [0,1] range

figure, hold on

%# draw outer circle
theta = linspace(5*pi/2, pi/2, 500)';  %# 'angles
r = max(radius(:));                    %# radius
x = r*cos(theta)+center(1);
y = r*sin(theta)+center(2);
plot(x, y, 'k:');

%# draw mid-circles
theta = linspace(5*pi/2, pi/2, 500)';  %# 'angles
num = 5;                               %# number of circles
rr = linspace(0,2,num+2);              %# radiuses
for k=1:num
    r = rr(k+1);
    x = r*cos(theta)+center(1);
    y = r*sin(theta)+center(2);
    plot(x, y, 'k:');
end

%# draw labels
theta = linspace(5*pi/2, pi/2, N+1)';    %# 'angles
theta(end) = [];
r = max(radius(:));
r = r + r*0.2;                           %# shift to outside a bit
x = r*cos(theta)+center(1);
y = r*sin(theta)+center(2);
str = strcat(num2str((1:N)','%d'),{});   %# 'labels
text(x, y, str, 'FontWeight','Bold');

%# draw the actual series
theta = linspace(5*pi/2, pi/2, N+1);
x = bsxfun(@times, radius, cos(theta)+center(1))';
y = bsxfun(@times, radius, sin(theta)+center(2))';
h = zeros(1,K);
clr = hsv(K);
for k=1:K
    h(k) = plot(x(:,k), y(:,k), '.-', 'Color', clr(k,:), 'LineWidth', 2);
end

%# legend and fix axes
legend(h, {'M1' 'M2' 'M3'}, 'location', 'SouthOutside', 'orientation','horizontal')
hold off
axis equal, axis([-1 1 -1 1] * r), axis off

    option1

    选项2

    %# some random data
K = 3;
N = 30;
data = zeros(K,N);
data(1,:) = 0.2*randn(1,N) + 1;
data(2,:) = 0.2*randn(1,N) + 2;
data(3,:) = 0.2*randn(1,N) + 3;

center = [0 0];                                %# center (shift)
radius = [data data(:,1)];                     %# added first to last to create closed loop
radius = normalize(radius',1)';                %# normalize data to [0,1] range
radius = bsxfun( @plus, radius, (1:2:2*K)' );  %# 'make serieson seperate ranges by addition

figure, hold on

%# draw outer circle
theta = linspace(5*pi/2, pi/2, 500)';   %# 'angles
r = max(radius(:))+1;                   %# radius
x = r*cos(theta)+center(1);
y = r*sin(theta)+center(2);
plot(x, y, 'k:');

%# draw mid-circles
theta = linspace(5*pi/2, pi/2, 500)';  %# 'angles
r = 1.5;                               %# radius
for k=1:K
    x = r*cos(theta)+center(1);
    y = r*sin(theta)+center(2);
    plot(x, y, 'k:');
    r=r+2;             %# increment radius for next circle
end

%# draw labels
theta = linspace(5*pi/2, pi/2, N+1)';    %# 'angles
theta(end) = [];
r = max(radius(:))+1;
r = r + r*0.2;                           %# shift to outside a bit
x = r*cos(theta)+center(1);
y = r*sin(theta)+center(2);
str = strcat(num2str((1:N)','%d'),{});   %# 'labels
text(x, y, str, 'FontWeight','Bold');

%# draw the actual series
theta = linspace(5*pi/2, pi/2, N+1);
x = bsxfun(@times, radius, cos(theta)+center(1))';
y = bsxfun(@times, radius, sin(theta)+center(2))';
h = zeros(1,K);
clr = hsv(K);
for k=1:K
    h(k) = plot(x(:,k), y(:,k), '.-', 'Color', clr(k,:), 'LineWidth', 2);
end

%# legend and fix axes
legend(h, {'M1' 'M2' 'M3'}, 'location', 'SouthOutside', 'orientation','horizontal')
hold off
axis equal, axis([-1 1 -1 1] * r), axis off

    option2

    我应该提到 normalize() 是一个自定义函数，它只执行minmax规范化（ (x-min)/(max-min) ），定义如下：

    function newData = normalize(data, type)
    [numInst numDim] = size(data);
    e = ones(numInst, 1);
    minimum = min(data);
    maximum = max(data);
    range = (maximum - minimum);

    if type == 1
        %# minmax normalization: (x-min)/(max-min)   =>   x in [0,1]
        newData = (data - e*minimum) ./ ( e*(range+(range==0)) );
    end

    %# (...)
end
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  • 7

    您可以找到here所有可用的MATLAB 2-D和3-D绘图功能 .

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  • 5

    对不起，如果这可能不是你问题的正确答案（你已经有很多） . 我最近发现了非常强大的绘制圆圈的工具 - CIRCOS：http://mkweb.bcgsc.ca/circos/看看，数字真是太棒了 . 它's not Matlab-based, but Perl, and it'是免费的 . 可能你会发现它很有用 .

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