Matlab matrices and vectors

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Steph surry
Steph surry on 6 Oct 2020
Commented: Steven Lord on 6 Oct 2020
A =[1,2,2,3,1,2,2] B =[1,2,2,2,2,2,2]
How to Generate a vector composed of first 4 elements of A and last 5 elements of B.
  4 Comments
Terin Richardson
Terin Richardson on 6 Oct 2020
There are several ways you could do this, the easiest just being C = horzcat(A(1:4), B(3:7)). horzcat stands for horizontal concatenation, meaning adding things horizontally. If these were column vectors, you would instead use the vertcat(A,B) function. You can also call these functions without using their names by creating arrays like this:
For horzcat: C = [A(1:4),B(3:7)]
For vertcat: C = [A(1:4);B(3,7)]
Note the difference in notation here is the horzcat uses a comma while the vertcat uses a semicolon.
If you want this to work for arrays of any size, meaning you always get the last 5 digits from B regardless of its size, you would need to use B(end-4:end) instead of B(3:7) in the line I listed above.
Steven Lord
Steven Lord on 6 Oct 2020
Since you're a beginner you may find the free MATLAB Onramp tutorial useful in familiarizing yourself with the basics of MATLAB.

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Answers (1)

KSSV
KSSV on 6 Oct 2020
Read about MATLAB indexing.......if A is given array.
A(1:3) % gives first three elements
A(end) % gives last element
A(1) % gives first element
size(A) % gives size
[A(1:2) A(4:end)] % joins two arrays
You should read basics of MATLAB instead asking such a simple questions.

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