Why do I receive Arrays have incompatible sizes for this operation

I am trying to write an if statement, to prevent the array Index in position 1 exceeding the array bounds, this is the code I have but I recieve an error message as seen below.

Level_Either_Side = [];
for p = 1:length(Componentry_New);
    if length(Componentry_New) < Position(1,p)+5
        Level_Either_Side == [Level_Either_Side Sorted_Level(Position(1,p)-5:Position(1,p),1)];
    elseif Level_Either_Side == [Level_Either_Side Sorted_Level(Position(1,p)-5:Position(1,p)+5,1)];
    end 
end 

This is the error message I recieve.

Error using  == 
Arrays have incompatible sizes for this operation.

I was using this code prevously and didn't recieve the above error message:

Level_Either_Side = [];
for p = 1:length(Componentry_New);
Level_Either_Side = [Level_Either_Side Sorted_Level(Position(1,p)-5:Position(1,p)+5,1)];
end 

Does anybody know where the eror in the code is, Thank you in advance.

Answer 1

[Walter Roberson]

You have an if that is then followed by a comparison not by an assignment.

        Level_Either_Side == [Level_Either_Side Sorted_Level(Position(1,p)-5:Position(1,p),1)];

The right hand side of that includes Level_Either_Side and 6 additional items. The left hand side of that includes Level_Either_Side . No matter what size Level_Either_Side is, the expression is size N on one side, and N+6 on the other side, and that can never match.