Find maxima in proximity

I have 2 timetables with data covering the same time period at 2 different intervals.

I want to find the local maxima in the Q timetable ('st_Q_exert') that is within a 24 hour window of the daily T ('st_T_exert') maximum.

I grouped them together using:

TT = synchronize(st_T_exert,st_Q_exert,'union', 'linear');

First, I need the daily T max. I did this using:

dailyTemp= reshape(TT.Temp(1:end-1),288,[]);
>> [valT,indT]=max(dailyTemp);

indT gives me the index of each day where the maxima occured. I would now like to find the maximas of the other data table in a 24 hour window around these indexes.

for i=2:length(indT)
    idxT_all(i)=indT(i)+288*(i-1);
end

This expands the indexing for the entire data set.

I would now like to do "search" the st_Q_exert in a window of size 288 around the indexes saved in idxT_all for the nearest maxima of Q around maxima of T.

Answer 1

[sai charan sampara]

Hello Raphael,

I understand you are trying to find the maximums in “st_Q_exert” around known indices of maximums in “st_T_exert” with a window of length 288. It can be done as follows:

load("Q_excerpt.mat");
load("T_excerpt.mat");
TT = synchronize(st_T_exert,st_Q_exert,'union', 'linear');
dailyTemp= reshape(TT.Temp(1:end-1),288,[]);
 [valT,indT]=max(dailyTemp);
 for i=2:length(indT)
    idxT_all(i)=indT(i)+288*(i-1);
 end
 max_q=[];
 for i=1:length(idxT_all)
     lower_limit=idxT_all(i)-143;
     upper_limit=idxT_all(i)+144;
     if lower_limit<1
         lower_limit=1;
     end
     if upper_limit>size(st_Q_exert,1)
         upper_limit=size(st_Q_exert,1);
     end
     max_q(i)=max(st_Q_exert{lower_limit:1:upper_limit,"Q"});
 end
 max_q

max_q = 1×14

14.3020 20.5780 20.3880 16.3650 15.2140 14.4540 14.4160 14.6070 13.8930 13.0060 36.8630 63.4560 28.2650 18.4160