How can get all the maximum and minimous values of peaks and valleys in a vector?

Question

Raul Torres 2018-5-7

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/399397-how-can-get-all-the-maximum-and-minimous-values-of-peaks-and-valleys-in-a-vector

回答： Yuvaraj Venkataswamy 2018-5-7

In the following code I'm trying to get the maximus and minimous of the graphic; I don't want to use max(i) because that would give me only the higher maximum point and I want the values of every peak and valley The code is shown next:

%close everything and clear everything
close all;
clear all;
clc;
% First we read an image wich must contain a graphic in it and then convert it to black and white
A=im2bw(imread('prueba3.png'));
%Show the image
figure();
imshow(A);
%Obtain the rows and columns
[F,U]=size(A);
i=1;
%Then we "sweep" the matrix looking for the black pixels defined by a 0 and save the
%position "(m,n)" in the vector "x" and "y"
for n=1:U;
     for m=1:F;
         if A(m,n)~=1;
             x(i)=n;
             y(i)=m;
           else
               m=m+1;
           end
       end
       n=n+1;  
       i=i+1;
  end
figure();
plot(x,y);
set(gca, 'YDir', 'reverse')