# how can i know if x position of a vector is empty?

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Erick Guzman
on 21 Jun 2022

Commented: Erick Guzman
on 21 Jun 2022

im trying this to know if that element(1,2) is empty or zero, to make a decision from that condition

if (ps1(1,2))==0

paredes1=1;

else

paredes1=length(ps1);

end

i was watching function like isempty or ismissing but its doesnt works.

##### 1 Comment

per isakson
on 21 Jun 2022

### Accepted Answer

Image Analyst
on 21 Jun 2022

Element (1,2) of a numerical array will never be empty. It can't be. A whole array can be empty, or you can set a whole column or row of a matrix to null ([]) which will delete the column or row, but then it will be gone and the array will be smaller. It will not be empty.

To determine if that element is 0 you can simply do

if ps(1,2) == 0

% That element is 0.

end

##### 0 Comments

### More Answers (1)

Karan Kannoujiya
on 21 Jun 2022

Hi Erick,

So you want to check whether a element is ps1(in your case) is 0 or not.

So, isempty or ismissing function will not work here. Because 0 is itself a element. If in a vector there is 0 it doesn't mean it is empty or missing. For checking a vector element for 0 then you must check by indexing as you have done.

therefore, isempty function is used to check if a memory location is allocated whether there is an element present or not.

for e.g lets take a string str=["abc" "xyz" ""]

So, in str at pos 3 we have allocated memory but there is no element present there

##### 5 Comments

Image Analyst
on 21 Jun 2022

A 1x2 vector (x,y) will have a length of 2 since the length is the length of the longest dimension. You should use size():

[rows, columns] = size(ps1)

By the way did you see my explanation below?

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