Reshaping 2d array

Question

venkat siddhartha rama 2019-10-20

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/486397-reshaping-2d-array

编辑： Andrei Bobrov 2019-10-22

采纳的回答： Andrei Bobrov

greetings friends,

Problem Definition:

I had a variable named Interpreted_power_1st_column = 105120 X 1 ;

This is the power availablitiy data at a location collected at every 5 mins interval for whole year.( 8760*12=105120) (there are 12 5 mins intervals in 1 hour ,and 8760 hours in 365 days)
I want the data to be avaerged to 1 hour interval, so I used reshape function in matlab( code below) to sum the 12 consequtive data points multiply by 5 and then divide the whole summation by 60....this is actually good way to get average data for 1 hour interval.

hourly_wind_energy1=zeros(8750,1);

hourly_wind_energy1=((sum(reshape(Interpreted_power*5,12,8760)))/60); %Hourly Wind energy generated from intepretation of power curve KW-hr

hourly_wind_energy1=hourly_wind_energy1';%%Hourly Wind energy generated from intepretation of power curve KW-hr

Now I have to do the same but Interpreted_power = 105120 X 5 (5 columns)

I have be trying various ways like for loops but couldnot achieve my final result.

Possible solution 1 : any experts who are well aware of reshape function help me with a possible way to do the process I have done in problem definityin for an variable with several columns (for now 105120 X 5, 5 columns)

Possible solution 2:

to create 5 different variables (Interpreted_power_1st_column, Interpreted_power_2nd_column, Interpreted_power_3rd_column, Interpreted_power_4th_column, Interpreted_power_5th_column)
Interpreted_power_1st_column has 1st column of Interpreted_power = 105120 X 5
Interpreted_power_2nd_column has 2nd column of Interpreted_power = 105120 X 5
Interpreted_power_3rd_column has 3rd column of Interpreted_power = 105120 X 5
Interpreted_power_4th_column has 4th column of Interpreted_power = 105120 X 5
Interpreted_power_5th_column has 5th column of Interpreted_power = 105120 X 5

Now follow the same procedure used in Problem definition ( Use reshape function 5 times for 5 of these variables, then combine all the results into single variable with 8760 X 5 )

Problem with solution 2 : I am having trouble creating individual column variables,

Interpreted_power_1st_column=Interpreted_power(1:end);

Interpreted_power_1st_column=Interpreted_power_1st_column'; %% this is giving 1st column elements

Interpreted_power_2st_column=Interpreted_power(2:end);

Interpreted_power_2st_column=Interpreted_power_2st_column'; %% but all below are not exactly the required column elements

Interpreted_power_3st_column=Interpreted_power(3:end);

Interpreted_power_3st_column=Interpreted_power_3st_column';

Interpreted_power_4st_column=Interpreted_power(4:end);

Interpreted_power_4st_column=Interpreted_power_4st_column';

Interpreted_power_5st_column=Interpreted_power(5:end);

Interpreted_power_5st_column=Interpreted_power_5st_column';

Thanks in advance

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David Hill 2019-10-22

Since you have an algorithm for (105120x1), just pass all columns into the function.

secondCol=powerMatrix(:,2);
thirdCol=powerMatrix(:,3);

Sebastian Bomberg 2019-10-22

I don't know which release you're on but starting from 2016b, if you had your data stored in a timetable you could simply call retime:

Thourly = retime(T,'hourly','mean')

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Answer 1

Andrei Bobrov 2019-10-22

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/486397-reshaping-2d-array#answer_397649

编辑：Andrei Bobrov 2019-10-22

As in comment by Sebastian Bomberg's (for MATLAB >= R2016b):

% Let A - your data of energy (150120 x 5 double)
TT = array2timetable(A,'RowTimes',(datetime(2018,1,1,0,0,0):minutes(5):datetime(2018,12,31,23,55,0))');
TT_hourly_mean = retime(TT,'hourly','mean');

if MATLAB <= R2016a:

[y,m,d,h,~,~] = datevec((datetime(2018,1,1,0,0,0):minutes(5):datetime(2018,12,31,23,55,0))');
T = [table(y,m,d,h),array2table(A)];
T_hourly_mean = varfun(@mean,T,'GroupingVariable',{'y','m','d','h'});