鲁达
两点之间的有向箭头
比如我们需要画一条从A点到B点的有向箭头。
涉及知识点：
矩阵的旋转 平移 缩放
1、main.m
% 根据两点坐标画箭头
clear;
close all;
start_point = [0, 0];
end_point = [3, 4];
draw_arrow(start_point, end_point);
2、draw_arrow.m
function draw_arrow(start_point, end_point)
% 从start_point到end_point画一箭头
K = 0.05; %箭头比例系数
theta = pi / 8; %箭头角度
A1 = [cos(theta), -sin(theta);
sin(theta), cos(theta)]; %旋转矩阵
theta = -theta;
A2 = [cos(theta), -sin(theta);
sin(theta), cos(theta)]; %旋转矩阵
arrow = start_point' - end_point';
arrow_1 = A1 * arrow; %旋转
arrow_2 = A2 * arrow;
arrow_1 = K * arrow_1 + end_point'; %缩放加平移
arrow_2 = K * arrow_2 + end_point';
hold on;
grid on;
axis equal;
plot([start_point(1), end_point(1)], [start_point(2), end_point(2)], 'k');
plot([arrow_1(1), end_point(1)], [arrow_1(2), end_point(2)], 'k');
plot([arrow_2(1), end_point(1)], [arrow_2(2), end_point(2)], 'k');
hold off;
3、运行结果
改变起点和终点的坐标，结果如下图所示。