필터 지우기
필터 지우기

Find intersection of two guassian curves

조회 수: 2 (최근 30일)
Trisha Kibaya
Trisha Kibaya 2018년 9월 11일
편집: jonas 2018년 9월 12일
Hi all these are my two curves:
y1 = p(1)*pdf(n1,xgrid); hold on; plot (xgrid, y1,'b'); % hold off
y2 = p(2)*pdf(n2,xgrid); hold on; plot (xgrid, y2,'r'); % hold off
I need to find the exact x coordinates where this two lines meet.
I tried using:
index_intersection = find(y1 == y2);
but it gives me index_intersection =
1×0 empty double row vector
I also tried:
idx = find (y1 - y2 < eps, 1);
but still didn't get the right coordinates.
Please, is there another alternative? I read online that I could use fzero, but I haven't understood how to use the syntax. Thanks in advance.
  댓글 수: 3
jonas
jonas 2018년 9월 11일
Check out InterX on FEX
Trisha Kibaya
Trisha Kibaya 2018년 9월 11일
numComponents=2;
paramEsts = fitgmdist(data(:),numComponents);
p = paramEsts.ComponentProportion;
and p has two values.
p =
0.3915 0.6085

댓글을 달려면 로그인하십시오.

채택된 답변

jonas
jonas 2018년 9월 11일
편집: jonas 2018년 9월 11일
If you have only one intersection, then you can just find the minimum difference
[~,idx] = min(abs(y1 - y2))
This will however always output a value even when there is no intersection. Also, the accuracy depends on the resolution of your x-vector, where higher resolution yields better accuracy (this is true for most methods). I always recommend InterX from FEX for finding intersections. It interpolates your data per default for high accuracy.
  댓글 수: 2
Trisha Kibaya
Trisha Kibaya 2018년 9월 12일
Please, pardon my ignorance but is FEX another MathWorks product? Cause i don't have that
jonas
jonas 2018년 9월 12일
편집: jonas 2018년 9월 12일
Sorry, FEX is short for fileexchange where you can find open source user-submitted functions. Follows the link in my answer, download and put it in your matlab search path

댓글을 달려면 로그인하십시오.

추가 답변 (1개)

KSSV
KSSV 2018년 9월 11일
편집: KSSV 2018년 9월 11일
tol = 10^-3 ; % Change this if required
idx = abs(y1-y2)<=tol ;
  댓글 수: 3
KSSV
KSSV 2018년 9월 11일
To compare two flottant numbers it is suggested to subtract check for inequality with tolerance, rather then using ==.
Trisha Kibaya
Trisha Kibaya 2018년 9월 12일
Thanks a lot

댓글을 달려면 로그인하십시오.

카테고리

Help CenterFile Exchange에서 Programming에 대해 자세히 알아보기

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by