Matlab make new array of values without a loop

2
votes

In Matlab, I don't know the best way to explain this except for an example. Let's say I have an array called tStart and a tDuration length:

tStart = [3,8,15,20,25];
tDuration = 2;

Is there some way to get a new array such that it would be: 

[3,4,5,8,9,10,15,16,17,20,21,22,25,26,27]

So what I want is to use the initial tStart array then make up a new array with the starting value and then next corresponding values for the length of tDuration.

If I do [tStart(1:end)+tDuration] I get an array of ending values, but how can I get the start, end, and all the values in between?

If I [tStart(1:end):tStart(1:end)+tDuration] I get an error.

Any help of a way to do this without a loop would be greatly appreciated.

1
arraysmatlabmatrixindexing

1 Answers

5
votes

I would use MATLAB's implicit expansion, reshape, and the ordering of 2d arrays.

First, create a 2d array containing the desired values from tStart:

tStart = [3,8,15,20,25];
tDuration = 2;

tDurAdd = [0:tDuration].';  % numbers to add to tStart
tArray = tStart + tDurAdd;

This gives us 

tArray =

    3    8   15   20   25
    4    9   16   21   26
    5   10   17   22   27

These are the correct values, now we just have to reshape them to a row vector:

tResult = reshape(tArray, 1, []);

The final array is:

tResult =

    3    4    5    8    9   10   15   16   17   20   21   22   25   26   27

Of course, this can all be done on one line:

tResult = reshape(tStart + [0:tDuration].', 1, []);