SOLVED

LAMBDA Bug - wrong output in array form

New Contributor

I created a LAMBDA function using Name manager which included an IF function to the GCD between the two input variables (one in the row & other in the column) and only to perform a calculation if the GCD = 1, otherwise the formula should return 0 as the answer.

 

the function works fine when used in an ordinary set-up. However, when I use it in the array format it fails to perform the IF function and perform the remaining calculation regardless of the GCD of the two inputs.

 

the formula is =LAMBDA(O,E,IF(GCD(E,O)=1,E^2+O^2,0)) and named as TOE in the name manager.

 

LAMBDA.JPG

 

the file can be accessed here

3 Replies

@MafazAnsar That's not a bug. When you use GCD on two arrays like in your example, the formula returns a single number 1. The the if_true argument is always executed producing the spilled array. 

 

Should you apply that formula on an array of 4's and another of 2's, GCD will return 2 which is not equal to 1. Thus, the LAMBDA produces a single 0.

You need to re-think and re-write the LAMBA. I haven't gotten that far.

@Riny_van_Eekelen thanks, In the workbook I have used odd numbers in the raws and even numbers in the columns. I tried changes everything to even numbers, basically, whichever the way it computes the GCD the answer should be at least 2, meaning the result should be 0. once I replaced all the odd numbers with even numbers, the formula output became 0 in the very first cell. not across the whole range. (screenshot below). I presume what you suggested was the case, may have to have a newer approach to writing the LAMBDA.

LAMBDA1.JPG

 

best response confirmed by MafazAnsar (New Contributor)
Solution

@MafazAnsar 

For the first sample

image.png

it could be

TOE=
LAMBDA( O, E,
    LET(
        fn, LAMBDA(O,E,IF(GCD(E,O)=1,E^2+O^2,0)),
        MAKEARRAY( ROWS(O), COLUMNS(E),
            LAMBDA(r,c, fn(INDEX(O,r), INDEX(E, c) ))
        )
    )
)