Question

我想绘制从北纬55度和东经20度的特定点开始的一些向量，并根据随机角度跟随方向（用randn生成）。我想过用循环来做这件事但是没有用完：

for i=1:100
    a=50+ 20.*randn;
    b = [a];
    i = i + 1;
    route = [20,50] + b * 
    plot(route, 'color', 'magenta')
    hold on
end

»»»route = [20,50] + b *我试过这样，因为对我而言，它看起来像是y = a + bx类型的愚蠢线性方程式...我只是不知道该怎么做用于x ... 这样它只会绘制1条路线，我需要100 ...

（所以我需要在一个图表上从相同的点开始的100个向量，其中唯一的参数变化是方向）

希望有人可以帮助我。有什么想法吗？

ps：我刚刚开始使用matlab。

Answer 1

1 - 对于带有方向的一行，请尝试以下代码：

%Initial line information
startPoint = [20 50] ;
direction  = [4 3] ;
lineLength = 100;

%Initialize line points with zeros
x  = zeros(lineLength);
y  = zeros(lineLength);

% Update line points
for i = 1 : lineLength
    x(i) = startPoint(1) + direction(1) * i;
    y(i) = startPoint(2) + direction(2) * i;
end

%Plot the line
plot( y , x ,'r.');

2 - 如果你想让每个点的方向发生变化，

使用以下代码：

%Initial line values
startPoint = [20 50] ;
lineLength = 100;

%create random direction vector
randomMax  = 100;
direction  = randi(randomMax,lineLength,2);

%Initialize line points with zeros
x  = zeros(lineLength);
y  = zeros(lineLength);

%set first points
x(1) = startPoint(1);
y(1) = startPoint(2);

% Update line points accumulating on previous point
for i = 2 : lineLength
    x(i) = x(i - 1) + direction(i,1) * i;
    y(i) = y(i - 1) + direction(i,2) * i;
end

%Plot the line
plot( y , x ,'r.');

3 - 对于具有不同方向的各种线路，请使用以下代码：

%Initial line values
startPoint = [20 50] ;
lineLength = 100;

%create random the 100 directions vector
randomMax  = 100;
directions = randi(randomMax,lineLength,2);

%Initialize line points with zeros
x  = zeros(lineLength,100);
y  = zeros(lineLength,100);

%set first points
x(1) = startPoint(1);
y(1) = startPoint(2);

h3 = figure;

% Update line points accumulating on previous point
for k = 1 : 100
    for i = 2 : lineLength

        x(i,k) = x(i - 1,k) + directions(k,1) * i;
        y(i,k) = y(i - 1,k) + directions(k,2) * i;

    end
    %hold the figure and plot the k-th line
    hold on;    
    plot( y(: , k) , x(: , k) , 'r.');
end

如何从起点绘制矢量并在matlab中跟随特定的度数方向？

1 个答案: