Invert the vector in matlab? Why not y(5:1)=x(1:5)?

[davyzhu]

matlab invert vector

How to invert the vector?

For example,
x=[1 2 3 4 5];
And I want y = [5 4 3 2 1];
But y(5:1)=x(1:5) seems cannot do that work.

Any suggestions will be appreciated!

Davy

 

[gfloros]

matlab vektor invertieren

It is very simple.
If you have a matrix x=[1 2 3 4 5]; run the following script:

for i=1:size(x,2)
y(size(x,2)-i+1)=x(i);
end

and you will get the y you want. The function size() returns the size of the matrix x.
Regards
Flo

 

[Element_115]

invert vector matlab

This is what you where trying to do.

x=[1 2 3 4 5];
y=x(5:-1:1)

You have to study how Matlab handles matrices and indexes. It
a little different from other standard methods.

Peace

 

[Samer El-Saadany]

matlab invert

about your question "Why not y(5,1)=x(1,5)?"
In Matlab y(m,n) means the element in the mth row and nth column.
i.e if you have this script
x=[1 2 3 4 5];
y(5,1)=x(1,5);

will give you a vector of one column and 5 rows
y=[0
0
0
0
5]
and it will assign all the remaining elements to zero as shown above.
I think that you will need a script as the one mentioned by gfloros.
or you can define it exlicitly
y=[5:-1:1] which means the starting element is 5 and the step is -1 till you reach the final element which is 1
Matlab is primarily based on Matrices and vectors, to get more help I think the Matlab getting started tutorial is the best refrence for that topic