Repeating array row n times with change of indexes

Hello everyone,

I have matrix of 1 minute data of the household load (5760x2, where 1st column reflects minutes and second the load). I need to transform data into seconds, where every row will be repeated 60 times with the change of indexes.

Ex.

1min x1 1 x1

2min x2 -----------------> 2 x1

... .....

5760min x5760 60 x1

61 x2

...

120 x2 etc.

I tried many different options and now I think it's involved in multiplying the matrices, but I can't solve this properly.

Can somebody help me? Thanks!

Answer 1

[Shubh Sahu]

Hello Jonna,

Let us suppose, the household data is in ‘a’, to repeat the number of rows repelem function is used:

u(:,2) = repelem(a(:,2),[60]);
u(:,1)=1:(5760*60);

for more information regarding repelem refer the following link:

https://www.mathworks.com/help/matlab/ref/repelem.html?searchHighlight=repeat&s_tid=doc_srchtitle

[madhan ravi]

When I run the above code:

u(:,2) = repelem(a(:,2),[60]);
u(:,1)=1:(5760*60);

I get an error. Could you explain what is being implied?

[Shubh Sahu]

Have a look on this, may it explains

clc;
clear all;
close all;

a=[1,5;2,7;3,8];% take a 3*2 matrix
u(:,2) = repelem(a(:,2),[60]);
u(:,1)=1:(size(a,1)*60);

[madhan ravi]

+1

Answer 2

[Joanna Widzinska]

It worked! Thank you very much :)