Finding a maximum period
4 visualizzazioni (ultimi 30 giorni)
Mostra commenti meno recenti
Hey Guys,
I'm trying to wrap my brain around how to find n maximum or minimum values in a row. I've used grpstats to generate mean values, but need to find the three highest or lowest in a row, so I can't use a sort function:
[m, g]=grpstats(data(:, 2), data(:, 1), {'mean', 'gname'})
m =
16.4605
19.6645
19.0127
20.0246
21.0003
20.0367
15.7379
22.7125
19.9485
20.4098
21.6320
17.6872
g =
'1'
'2'
'3'
'4'
'5'
'6'
'7'
'8'
'9'
'10'
'11'
'12'
Any ideas or functions to suggest? Thanks and all the best.
2 Commenti
Walter Roberson
il 18 Gen 2017
Are you looking for a moving maximum, where every point is replaced by the maximum of the point and the point before and the next point? Are you looking for a single group of three values in a row that has the highest average out of all of the sliding possibilities?
Risposta accettata
Image Analyst
il 18 Gen 2017
If you're looking for the group of 3 elements that have the highest sum (and mean) then you can use conv() or movmean()
threeElementSum = conv(data, [1,1,1], 'same');
[maxSum, indexOfMax] = max(threeElementSum);
This will tell you where the center of the 3 element window is where the values inside that 3 element window have the highest sum of any window location in the data. Is that what you're looking for?
Più risposte (1)
Alexandra Harkai
il 18 Gen 2017
If you're looking for the n highest and lowest entry for each row of input data, you can still use the sort function:
[sorted, row_idx] = sort(data, 2);
sorted will contain the sorted data, row_idx will contain the row-wise indices, so:
sorted(:,1:n) % n smallest elements in each row
sorted(:,(end+1-n):end) % n largest elements in each row
row_idx(1,1:n) % indices in rows for the n smallest elements in each row
row_idx(1,(end+1-n):end) % indices in rows for the n largest elements in each row
1 Commento
Vedere anche
Categorie
Scopri di più su Data Preprocessing in Help Center e File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!