Algorithm 交集,多重根
我很难确定这个基本逻辑。给定两个函数:y1和y2,在MATLAB中绘制在x上。如何使用simpleforloop和if-else语句确定交点。这些y1和y2有多个交叉点。我很确定我在循环中遗漏了一些东西Algorithm 交集,多重根,algorithm,matlab,plot,intersection,Algorithm,Matlab,Plot,Intersection,我很难确定这个基本逻辑。给定两个函数:y1和y2,在MATLAB中绘制在x上。如何使用simpleforloop和if-else语句确定交点。这些y1和y2有多个交叉点。我很确定我在循环中遗漏了一些东西 clc clear x = linspace(0,2); y1 = 2.*x + 1; y2 = exp(x); tol = 0.05; x_intercept = zeros(size(x)); y_intersect = zeros(size(x)); for i = 1:100 i
clc
clear
x = linspace(0,2);
y1 = 2.*x + 1;
y2 = exp(x);
tol = 0.05;
x_intercept = zeros(size(x));
y_intersect = zeros(size(x));
for i = 1:100
if abs(y1(i) - y2(i)) == tol
y_intersect = y2(x(i));
x_intercept = x(i);
end
end
plot(x,y1)
hold on
plot(x,y2)
plot(x_intercept, y_intersect,'xr');
你能帮忙吗?我很抱歉,如果这似乎是一个非常简单的问题,但我已经搜索,并没有找到答案。我发现的只是使用polyval/polyfit等工具,但这些工具只显示一个交点 尝试将for循环更改为:
ctr=1;
for i = 1:100
if abs(y1(i) - y2(i)) <= tol
y_intersect(ctr) = y2(i);
x_intercept(ctr) = x(i);
ctr=ctr+1;
end
end
ctr=1;
对于i=1:100
如果abs(y1(i)-y2(i))可以使用该函数查找两条曲线的交点:
clc
clear
% Define the symbolic variables
syms x y
vars=[x y]
% Define the two eqautions
equations=([2*x+1-y == 0,exp(x)-y == 0])
% Call SOLVE to find the intersection point
[sol_x,sol_y]=solve(equations,vars,'Real', true)
% Get the values of the x and y coordinates of the intersectiin points
x_inters=double(sol_x)
y_inters=double(sol_y)
% Evaluate the two functions (only to plot them)
x = linspace(0,2);
y1 = 2.*x + 1;
y2 = exp(x);
plot(x,y1)
hold on
plot(x,y2)
% Add the intersection points
plot(x_inters,y_inters,'or','markerfacecolor','r')
如果您想/需要使用for
和If else
语句,则首先需要修改代码中的If
条件:
if abs(y1(i) - y2(i)) <= tol
希望这有帮助
Qapla’不客气。如果答案解决了你的问题,你可以接受它,让社区知道问题已经解决
clc
clear
% x = linspace(0,2);
% Define the x samaples
x=0:.001:2
y1 = 2.*x + 1;
y2 = exp(x);
% tol = 0.05;
tol = 0.001;
x_intercept = zeros(size(x));
% y_intersect = zeros(size(x));
y1_intersect = zeros(size(x));
y2_intersect = zeros(size(x));
% Initialize the counters
cnt=0;
once=0;
% Initialize the minimun_difference
min_diff=999;
% for i = 1:100
% Loop over the xsamples
for i = 1:length(x)
% if abs(y1(i) - y2(i)) == tol
y1_y2_diff=abs(y1(i) - y2(i));
if(y1_y2_diff <= tol)
% If the difference is lower than the threshold, set the flag to
% increment the number of solutions
if(~once)
cnt=cnt+1;
once=1;
end
% Store the values for the minimum difference
if(y1_y2_diff <= min_diff)
min_diff=y1_y2_diff;
y1_intersect(cnt) = y1(i);
y2_intersect(cnt) = y2(i);
x_intercept(cnt) = x(i);
end
else
% Rese the flag
min_diff=999;
once=0;
end
end
plot(x,y1)
hold on
plot(x,y2)
% plot(x_intercept, y_intersect,'xr');
plot(x_intercept(1:cnt), y1_intersect(1:cnt),'xr');
plot(x_intercept(1:cnt), y2_intersect(1:cnt),'dr');