How to detect differencens between 2 vectors that are sorted?

1 Ansicht (letzte 30 Tage)
I have to following problem: I got a vector A = [1 20 3650 4000 NaN NaN] of fixed size (here 6). Given A I generate B in such a way that I generate a new value depending on the last non-NaN value of A (in this case 4000). The new Value is now 4000*rand. For example 4000*rand = 1111. So B becomes B = [1 20 1111 3650 4000 NaN], also of fixed Size 6 and sorted. More precisely the value 1111 is appended to the vector A and then sorted so that it becomes B.
But if I just have B and A given and the knwoledge of the generation process, how can I detect the 1111? My naive approch would be, looping from 1 to end through all the elements and since I know the vectors are sorted the first missmatch is the new element. But I wondered whether their is a nicer/faster solution for this?
Thanks in advance!
  2 Kommentare
Azzi Abdelmalek
Azzi Abdelmalek am 24 Aug. 2015
Please give a correct example, in your example B is 1x5 not 1x6 like you said, and explain how 4000*rand is located in your new matrix?
vthuongt
vthuongt am 24 Aug. 2015
Thanks for your remark. I edited the question for clarification.

Melden Sie sich an, um zu kommentieren.

Akzeptierte Antwort

Bjorn Gustavsson
Bjorn Gustavsson am 24 Aug. 2015
Surely this answer is what your teacher want you to learn:
setdiff(B,A)
  2 Kommentare
vthuongt
vthuongt am 24 Aug. 2015
Bearbeitet: vthuongt am 24 Aug. 2015
Thank you very much. This function seems to be exactly what I needed. I have no teacher :) This problem arouse in another larger program I am working on. But anyways- how does this function performs in contrast to the for-loop? If for example I have much bigger sets?
Bjorn Gustavsson
Bjorn Gustavsson am 24 Aug. 2015
I have no idea but just became curious. Please investigate and then tell us about the results.

Melden Sie sich an, um zu kommentieren.

Weitere Antworten (0)

Produkte

Community Treasure Hunt

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

Start Hunting!

Translated by