Why need if(Sum([Sales Margin Amount])/Sum([Sales Amount]) < 0,0, before compute GP% ?

[paulyeo11]

Hi All

I have notice that QS example expression on compute GP% as below ::-

if(Sum([Sales Margin Amount])/Sum([Sales Amount]) < 0,0,Sum([Sales Margin Amount])/Sum([Sales Amount]))

Usually i get below :-

Sum([Sales Margin Amount])/Sum([Sales Amount]))

Can some one share with me why need to add ?

if(Sum([Sales Margin Amount])/Sum([Sales Amount]) < 0,0,

I believe it is for remove those -ve GP%.

Paul