Octave 如何在GNU八度音阶中画圆

在这种情况下：

R = 10;
Center = [5,8];
circle(Center,R,1000,'b-');
hold on
plot(Center(1),Center(2),'g.')

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同样的MatLab代码不适用于GNU倍频程。给定中心x、y坐标和半径，哪个倍频程代码会绘制一个圆？

如果您想要一个可重用的函数，这里有一种可能性：

t = linspace(0,2*pi,100)'; 
circsx = r.*cos(t) + x; 
circsy = r.*sin(t) + y; 
plot(circsx,circsy); 

function [h, hc] = circles(x,y,r,cmrk)
% CIRCLES   plot 2-D circles, given a set of center coordinates and radii.
%
% Description:
%
%   Plot 2-D circles, given a set of center coordinates and radii. Values
%   can be vectors or matrices, as long as dimensions are consistent. If
%   a marker type (e.g. '+') is also given, circle centers will be marked
%   with it. The function returns a vector of handles for each circle and
%   a handle for all the center markers, if plotted.

assert(size(x)==size(y), 'Mismatching sizes')
assert(size(y)==size(r), 'Mismatching sizes')

if (nargin==4)
    hc = scatter(x,y,[],[],cmrk);
end
axis([min(x-r) max(x+r) min(y-r) max(y+r)], 'equal');

a = linspace(0, 2*pi, 12);
dx = sin(a); dy = cos(a);
hold on
for i=1:numel(x);
    h(i) = line(x(i)+dx*r(i), y(i)+dy*r(i));
end
hold off

下面是一个用法示例：

x = 0:.1:2*pi; y = sin(x); r = rand(size(x))*.3;
circles(x, y, r, '+')

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以GNU倍频程绘制一个圆：

x = -3:0.01:3;
y = (4 - x .^ 2) .^ 0.5;
figure; plot(x,y); hold on; plot(x,-y);

octave> x = -1:0.01:1;
octave> y = (1 - x .^ 2) .^ 0.5;
octave> plot(x,y, "linewidth", 4, x,-y, "linewidth", 4);

octave> r = 1;
octave> t = linspace(0,2.*pi,1);
octave> circsx = r.*cos(t) + x;
octave> circsy = r.*sin(t) + y;
octave> plot(circsx,circsy, "linewidth", 4, circsx, -circsy, "linewidth", 4); 

---

画一个圆，方程x^2+y^2=4

使用倍频程额外包倍频程几何体，您可以将函数用作

从下载软件包

八度：

• pkg安装路径到文件.tar.gz

• pkg装载几何图形

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如何在gnu倍频程版本3.8中绘制圆：

x = -3:0.01:3;
y = (4 - x .^ 2) .^ 0.5;
figure; plot(x,y); hold on; plot(x,-y);

octave> x = -1:0.01:1;
octave> y = (1 - x .^ 2) .^ 0.5;
octave> plot(x,y, "linewidth", 4, x,-y, "linewidth", 4);

octave> r = 1;
octave> t = linspace(0,2.*pi,1);
octave> circsx = r.*cos(t) + x;
octave> circsy = r.*sin(t) + y;
octave> plot(circsx,circsy, "linewidth", 4, circsx, -circsy, "linewidth", 4); 

代码：

x = -3:0.01:3;
y = (4 - x .^ 2) .^ 0.5;
figure; plot(x,y); hold on; plot(x,-y);

octave> x = -1:0.01:1;
octave> y = (1 - x .^ 2) .^ 0.5;
octave> plot(x,y, "linewidth", 4, x,-y, "linewidth", 4);

octave> r = 1;
octave> t = linspace(0,2.*pi,1);
octave> circsx = r.*cos(t) + x;
octave> circsy = r.*sin(t) + y;
octave> plot(circsx,circsy, "linewidth", 4, circsx, -circsy, "linewidth", 4); 

语言化：

x = -3:0.01:3;
y = (4 - x .^ 2) .^ 0.5;
figure; plot(x,y); hold on; plot(x,-y);

octave> x = -1:0.01:1;
octave> y = (1 - x .^ 2) .^ 0.5;
octave> plot(x,y, "linewidth", 4, x,-y, "linewidth", 4);

octave> r = 1;
octave> t = linspace(0,2.*pi,1);
octave> circsx = r.*cos(t) + x;
octave> circsy = r.*sin(t) + y;
octave> plot(circsx,circsy, "linewidth", 4, circsx, -circsy, "linewidth", 4); 

以

.01

的增量创建一个介于-1和1之间的列表，以表示x轴。y轴是圆的直径减去x平方的每个索引处的值，所有值均升高到

0.5

绘制x和y（蓝色），给出圆的上半部分，然后绘制x到-y，反转顶部（绿色），创建圆的下半部分

或者，使用linspace：

代码：

x = -3:0.01:3;
y = (4 - x .^ 2) .^ 0.5;
figure; plot(x,y); hold on; plot(x,-y);

octave> x = -1:0.01:1;
octave> y = (1 - x .^ 2) .^ 0.5;
octave> plot(x,y, "linewidth", 4, x,-y, "linewidth", 4);

octave> r = 1;
octave> t = linspace(0,2.*pi,1);
octave> circsx = r.*cos(t) + x;
octave> circsy = r.*sin(t) + y;
octave> plot(circsx,circsy, "linewidth", 4, circsx, -circsy, "linewidth", 4); 

语言化：

x = -3:0.01:3;
y = (4 - x .^ 2) .^ 0.5;
figure; plot(x,y); hold on; plot(x,-y);

octave> x = -1:0.01:1;
octave> y = (1 - x .^ 2) .^ 0.5;
octave> plot(x,y, "linewidth", 4, x,-y, "linewidth", 4);

octave> r = 1;
octave> t = linspace(0,2.*pi,1);
octave> circsx = r.*cos(t) + x;
octave> circsy = r.*sin(t) + y;
octave> plot(circsx,circsy, "linewidth", 4, circsx, -circsy, "linewidth", 4); 

---

绘制一个圆。

在“geometry”包中有一个内置函数，可用于绘制不同的几何形状。下面是圆的代码：

pkg load geometry
drawCircle (x0, y0, r)

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我有几种画圆的方法，这是一种简单的方法

pkg load geometry
x=0;
y=0; #center point ordered pair
r1=10; #radius of circule
h1=drawCircle(x,y,r1);

如果你想让卓尔再绕一圈

hold on;
r2=8;
h2=drawCircle(x,y,r2);

另一种方法是

angle=linspace(0,2*pi,360);

r=5; #radius

x=2;

y=5; #x and y is hear center point 

horizantalValue=r*cos(angle)+x;

verticalValue=r*sin(angle)+y;

plot(verticalValue,horizantalValue);

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您能否提供一个完整的示例，说明您正在使用的八度音阶版本？八度音阶3.2.4的完整示例：。这就是它的样子：为什么不把这个函数贡献给倍频程呢？它写得很好，可能对未来的用户有用。我只是将其重命名为与Matlab兼容。