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标题: 用MATLAB计算曲率 [打印本页]

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作者: uperrua    时间: 2020-4-21 10:44
标题: 用MATLAB计算曲率
曲率公式：
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注意：
①曲率半径为曲率的倒数
②如果是离散点，先用polyfit和polyval拟合出曲线
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程序：


clc; clear all; close all;
6 {8 t4 h' a7 `' }% ex0 = linspace(0, 1);
y0 = sin(x0).*cos(x0);
) j, i6 R- A% K# S: eh = abs(diff([x0(2), x0(1)]));
6 _4 C, z# `( O1 \; N1 c& \% D% 模拟一阶导
9 Z  r& u* J/ Ffigure; box on; hold on;
* c) p  `  a" K4 mythe1 = cos(x0).^2 - sin(x0).^2; %理论一阶导
yapp1 = gradient(y0, h); %matlab数值近似
' [$ X4 E* @7 p3 x: @$ n+ ]plot(x0, ythe1, '.');
, I( S& b! D0 u9 C  R1 qplot(x0, yapp1, 'r');
6 ?( a( `8 n% C8 F/ elegend('理论值', '模拟值');
5 z4 t6 s) e" q# b4 ftitle('模拟一阶导');
% 模拟二阶导
' P% @4 S; {5 X9 i. M2 G1 Y! hfigure; box on; hold on;
$ f4 o! I/ I2 k' f5 y4 Sythe2 = (-4)*cos(x0).*sin(x0); %理论二阶导
& m, `9 b2 F( K& T7 ayapp2 = 2*2*del2(y0, h); %matlab数值近似
9 E8 _. F  N& d; rplot(x0, ythe2,'.');
" u" U4 ?% \8 H6 u% a( D0 lplot(x0, yapp2,'r');
legend('理论值', '模拟值');
title('模拟二阶导');
/ h. U( ^8 Y' p' {& f$ {9 |- m% 模拟曲率
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1 A. @7 m# ]6 w  Y9 N, A# Y& w' Jy = sin(x)*cos(x);
yd2 = diff(y, 2);
yd1 = diff(y, 1);
k = abs(yd2)/(1+yd1^2)^(3/2);
k1 = subs(k, x, x0);
k2 = abs(yapp2)./(1+yapp1.^2).^(3/2);
" q5 w, X6 n* h" O) }figure; box on; hold on;
plot(x0, k1, '.');
plot(x0, k2, 'r');
1 }  A, Y. T5 Hlegend('理论值', '模拟值', 'Location', 'NorthWest');
- M; @) v9 Z/ w( w# s* Wtitle('模拟曲率');




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作者: CCxiaom    时间: 2020-4-21 13:28
用MATLAB计算曲率

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作者: NingW    时间: 2020-4-23 13:23
用MATLAB计算曲率

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