Find intersecting points of two functions
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I need to find the intersecting points ofr two functions but it only works for simple functions
If I try it with trig funtions it tells me my index exceeds my number of arrays, how do I fix this???
dx = 1/10;
x = 0:dx:10;
fun_1 = (power(x,2));
fun_2 = (x);
find (x==1)
difference = abs(fun_1 - fun_2);
sub_script = find (difference == min(difference) );
%%
difference = abs(fun_1 - fun_2);
min_difference = min(difference);
intersect_subs = find(difference == min(difference) );
sub_1 = intersect_subs(1);
sub_2 = intersect_subs(2); %tells me the error is here..
x_intersect_1 = x(sub_1);
x_intersect_2 = x(sub_2);
point_1 = fun_1(sub_1);
point_2 = fun_2(sub_2);
figure(1)
plot(x, fun_1,...
x, fun_2,...
x_intersect_1, point_1, 'ko',...
x_intersect_2, point_2, 'ko', 'Markersize', 7)
5 Comments
darova
on 18 Mar 2020
Because you have only one minimum point
sub_script = find (difference == min(difference) ); % sub_script is 1x1 size
Isaac Fife
on 18 Mar 2020
darova
on 18 Mar 2020
I see only one intersection point

Isaac Fife
on 18 Mar 2020
darova
on 18 Mar 2020
Can't you just use polyxpoly?
Answers (1)
Sajeer Modavan
on 18 Mar 2020
clc
clear
dx = 1/100;
x = 0:dx:2;
fun_1 = (power(x,2));
fun_2 = (x);
intersect_subs = find(round(fun_1,1) == round(fun_2,5));
figure(1)
plot(x, fun_1,...
x, fun_2,...
x(intersect_subs), fun_1(intersect_subs), 'ko', 'Markersize', 7)
%%
dx = 1/100;
x = 0:dx:2;
fun_1 = (cos(x));
fun_2 = (x);
intersect_subs = find(round(fun_1,1) == round(fun_2,1));
figure(2)
plot(x, fun_1,...
x, fun_2,...
x(intersect_subs), fun_1(intersect_subs), 'ko', 'Markersize', 7)
1 Comment
Sajeer Modavan
on 19 Mar 2020
is it solved your problem?
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