How to plot 2 lines and find the coordinates of their intersection?
923 ビュー (過去 30 日間)
古いコメントを表示
I need to plot the lines x+y=3 and x-y= -1 and find their point of intersection. I know that to plot the lines I could use 'fplot'. How can I find the coordinates of their intersection and plot it? Please help.
0 件のコメント
回答 (5 件)
Star Strider
2017 年 9 月 17 日
Another approach:
xymtx = [1 1; 1 -1];
cv = [3; -1];
xy = xymtx\cv; % Calculate Intercept
xint = xy(2); % X-Value Of Intercept
yint = xy(1); % Y-Value Of Intercept
xyind = [xint - 1, xint + 1]'; % X-Values For Plot
xydep = [cv -xyind.*xymtx(:,2)]; % Y-Values For Plot
figure(1)
plot(xyind, xydep(1,:), xyind, xydep(2,:), '-r')
hold on
plot(xint, yint, 'pg', 'MarkerFaceColor','g', 'MarkerSize',10)
hold off
This is straightforward and relatively simple linear algebra. The ‘xydep’ variable calculates the y-values corresponding to the arbitrary values in ‘xydep’, and is the result of solving ‘[X + Y] = C’ for ‘Y’.
0 件のコメント
Tutku Oztel
2019 年 1 月 9 日
Hello,
I'm sharing the function that I wrote to find the intersection points of two lines with their given slope and constant values:
function [x0 y0] = intersectPoints(m1,m2,b1,b2)
% Insersection point of two lines with known slope and constant
% parameters.
% [x0 y0] = intersectPoints(m1,m2,b1,b1)
% where m's are slope, and b's are constants.
% written by Tutku Öztel in 06.01.2019
x0 = (b2-b1)/(m1-m2); %find the x point
y0 = m1*x0+b1;
end
Late though, but still.. Hope it will be helpful! :)
Tutku
2 件のコメント
Simon Kölbl
2017 年 9 月 17 日
I would do it like this:
% define x Axis and evaluate functions
x_points = -5:0.1:5;
function1 = -x+1;
function2 = x+1;
index_intersection = find(function1 == function2);
x_value_intersection = x_points(index_intersection);
y_value_intersection = function1(index_intersection);
% plot functions and intersection point:
curve1 = plot(x_points, function1);
hold on
curve2 = plot(x_points, function2);
intersection = plot(x_value_intersection, y_value_intersection,...
'Marker', '+', 'MarkerSize', 6, 'Color', 'r');
2 件のコメント
Image Analyst
2021 年 6 月 5 日
clc; % Clear command window.
fprintf('Running %s.m ...\n', mfilename);
clear; % Delete all variables.
close all; % Close all figure windows except those created by imtool.
workspace; % Make sure the workspace panel is showing.
% Define x Axis and evaluate functions
x_points = -5:0.1:5;
function1 = -x_points+1;
function2 = x_points+1;
index_intersection = find(function1 == function2);
x_value_intersection = x_points(index_intersection)
y_value_intersection = function1(index_intersection)
% Plot functions and intersection point:
curve1 = plot(x_points, function1);
hold on
curve2 = plot(x_points, function2);
intersection = plot(x_value_intersection, y_value_intersection,...
'Marker', '+', 'MarkerSize', 20, 'Color', 'r', 'LineWidth', 2);
grid on
caption = sprintf('At intersection, x = %f, y = %f', x_value_intersection, y_value_intersection);
fontSize = 15;
title(caption, 'FontSize', 15);
xlabel('x', 'FontSize', 15);
ylabel('y', 'FontSize', 15);
fprintf('Done running %s.m\n', mfilename);
Preetham Manjunatha
2022 年 2 月 8 日
Here is the link to find the intersection point of two line segments/lines. A fast two line intersection point finder based on the line parametric space. Finds the intersection point between two lines if it exists or else submits NaN. if you need to find the intersection of the multiple line segments, MATLAB's Mapping Toolbox has function polyxpoly - that finds the intersection points for lines or polygon edges.
0 件のコメント
参考
カテゴリ
Help Center および File Exchange で Annotations についてさらに検索
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!