How can I create a new column in a table via if function?

I have a 45060x3 timetable, where the value kW ranges form 0 to 800. Now I want to create a new column (charger) which is definded by the if function down below. However when I execute this code, it creates a column (charger) where all the values equal the ones in kW even there are a lot of values which fullfill the if statement. Can you tell me what is the problem with this code? Or is there a other way to get the values I want for the new column?

if T3DHM18.kW<=400
   T3DHM18.charger=T3DHM18.kW+150  %%Take the values form T3DHM18.kW and add 150
else 
   T3DHM18.charger=T3DHM18.kW      %%if x>400 than it is same as T3DHM18.kW
end

Answer 1

[David Fletcher]

By way of a smaller example -

%Create dummy table for the purpose of example
tbl=table()
tbl.KW=(1:10)'

%Copy KW column to a new charger column
tbl.Charger=tbl.KW

%Create indexer into the table for all rows where KW<4
ind=tbl.KW<4
%Add 150 to the rows where KW is less than 4
tbl.Charger(ind,:)=tbl.Charger(ind,:)+150

tbl =

10×2 table

    KW    Charger
    __    _______

     1    151    
     2    152    
     3    153    
     4      4    
     5      5    
     6      6    
     7      7    
     8      8    
     9      9    
    10     10

[Jennifer Pichl]

Thank you very much!

Answer 2

[Peter Perkins]

Another possibility, similar to David's solution:

T3DHM18.charger = T3DHM18.kW + 150*(T3DHM18.kW<=400)

The problem with the original code is that the if statement is written with element-wise assignment in mind, while the assignment itself is vectorized. When given a logical vector, an if statement evaluates only the first element (for historical reasons).