Extract group of identical values from an array
1 visualización (últimos 30 días)
Mostrar comentarios más antiguos
Sugyani Mahapatra
el 7 de Jul. de 2017
Comentada: Sugyani Mahapatra
el 7 de Jul. de 2017
I have the array
a = [0 0 0 1 1 1 0 0 0 0 0 1 1 1 1 0 0 1 1];
I want to extract the first and last index where a==1 as a group
o/p: [4 6; 12 15; 18 19];
Is there any efficient way to do this?
1 comentario
Adam
el 7 de Jul. de 2017
Editada: Adam
el 7 de Jul. de 2017
firstIndices = find( diff(a) == 1) + 1;
lastIndices = find( diff(a) == -1);
will give you most of what you need, but you would need to make a special case for the last index which it will not find, and obviously it is more efficient to do the diff just once, etc. Shaping the results into the format you want shouldn't be difficult.
Respuesta aceptada
Más respuestas (1)
C.J. Harris
el 7 de Jul. de 2017
a = [0 0 0 1 1 1 0 0 0 0 0 1 1 1 1 0 0 1 1];
nStart = find(diff([0 a 0]) == 1);
nEnd = find(diff([0 a 0]) == -1) - 1;
nResult = [nStart' nEnd'];
0 comentarios
Ver también
Categorías
Más información sobre Operators and Elementary Operations en Help Center y File Exchange.
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!