set absolute values for Expression

Question

I need to set absolute value for the following expression

formula Dealt_sigma = |Mean_new - Mean_refrence| /(sigma)
delta_sigma cannot be negative.

Delta_sigma.Expression = "(Convert(mean_new,'System.Double')-Convert(Mean_refrence,'System.Double'))/(sigma)";

Vulpes · Answer

IIF(condition a b) is equivalent to the C# ternary operator: condition ? a : b where 'condition' is a bool and 'a' and 'b' are values of the same type. So if condition is true it returns 'a' and if it's false it returns 'b'. Conceptually it's simple enough though where you have complex expressions you can drown in a sea of brackets if you're not careful! Check this link for everything that's allowed in the Expression property: http://msdn.microsoft.com/en-us/library/system.data.datacolumn.expression(v=vs.110).aspx

Farhan Shariff · Answer

Seriously you are the best.It is working. I have to learn this IIF. thanks_a_lot Vulpes

Vulpes · Answer

Good that makes life a little easier :) So try this: Delta_sigma.Expression = IIF((Convert(Mean_new'System.Double') - Convert(Mean_refrence'System.Double')) >= 0.0 Convert(Mean_new'System.Double') - Convert(Mean_refrence'System.Double') Convert(Mean_refrence'System.Double') - Convert(Mean_new'System.Double'))/sigma;

Farhan Shariff · Answer

sigma is not negative or zero it is a positive value

Vulpes · Answer

You'll need to use IIF here as Math.Abs isn't supported in the Expression property. To enable me to come up with an answer can you advise whether the 'sigma' column could be negative or zero?