Using Null() in Calculated Dimension

[#1]

So I have a table where I want to hid any rows that have no value for a specific expression regardless if there is any data in the other expression fields.  See below for example of my table.  What I am trying to do is write a calculated dimension for "RVP" that would allow me to suppress the null values.  I am using the following but get and Error in Calculated Dimension.

if( (COGS/REVENUE) =0, NULL(), [RVP])

I would then supress the null values ideally eliminating RVPs "G" and "H" from the table.

Dimension	Dimension	Expression	Expression	Expression
RVP	Region	Revenue	COGS	COGS % Rev
A	1	$ 10,000	$ 5,000	50%
B	2	$ 20,000	$ 6,000	30%
C	3	$ 30,000	$ 7,000	23%
D	4	$ 40,000	$ 8,000	20%
E	5	$ 50,000	$ 9,000	18%
F	6	$ 60,000	$ 10,000	17%
G	7	$                 -	$                 -
H	8	$                 -	$                 -

Thanks in advance

[sunny_talwar]

May be try using the aggregate function

Aggr(If(Expression4Revenue = 0 or Expression4COGS = 0, Null(), RVP), RVP, Region)