Help me find the index value for first minimum value in a matrix.

6 visualizaciones (últimos 30 días)
I have a matrix
A=[ 34 67 78 88 4 15 23 67 78 56 3 2 24 67]
First minimum value in this matrix is 4. (this is first drop). Index of 4 is 5.
After 4 many minimum value is there (i.e) 2.
I don't want to consider the other minimum value 2.
I want index of first minimum value (i.e first drop) as a output...
output =( first minimum value 4 and its index is 5)
someone please suggest me a code to solve this..

Respuesta aceptada

Walter Roberson
Walter Roberson el 29 de Mzo. de 2021
A=[ 34 67 78 88 4 15 23 67 78 56 3 2 24 67]
A = 1×14
34 67 78 88 4 15 23 67 78 56 3 2 24 67
find(diff(A) < 0, 1)
ans = 4

Más respuestas (2)

Bruno Luong
Bruno Luong el 29 de Mzo. de 2021
[~,idx] = min(A)
  5 comentarios
Walter Roberson
Walter Roberson el 29 de Mzo. de 2021
OP stands for "Original Poster"
Bruno Luong
Bruno Luong el 29 de Mzo. de 2021
Not sure your definition of "first drop", but try this
d=diff(A);
find(d(1:end-1)<=0 & d(2:end)>=0,1,'first')+1

Iniciar sesión para comentar.


Riley
Riley el 29 de Mzo. de 2021
Editada: Riley el 29 de Mzo. de 2021
A=[ 34 67 78 88 4 15 23 67 78 56 3 2 24 67];
flag=0;
for i=1:length(A)-1
if flag==0&&A(i+1)<A(i)
flag=1;
continue;
end
if flag==1&&A(i)<A(i+1)
first_min=A(i);
idx=i;
break;
else
flag=0;
end
end
first_min
idx
Hi, OP means original poster which is you here. The code above can find the first minimum value and its indice, only if 4 is the first drop. As you can see, if the number ahead of 4 is smaller than 88, this code fails. This is not the perfect solution. Hope you can find a better one.

Categorías

Más información sobre Matrix Indexing en Help Center y File Exchange.

Etiquetas

Community Treasure Hunt

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

Start Hunting!

Translated by