Calculation using LINQ

[shapper]

Hello,

I have a List<MyObject> where MyObject has two properties: N (int) and
Weight (int).

In this list only the N is defined for each tag.

I want to calculate the Weight for each MyObject in the list, as
follows:

Weight of MyObject = N of Tag / Maximum N of all MyObject in list

How can I do this using a Linq expression?

Thanks,
Miguel

 

[Alex Meleta]

Hi shapper,

It can be like this:

var secondList = from item in list select new MyObject
{
N = item.N,
Weight = item.N/ (from aggitem in list select item.N).Max() // or simple
list.Max(l => l.N)
};

Regards, Alex Meleta
mailto:[email protected]; blog:devkids.blogspot.com

 

[Pavel Minaev]

It can be like this:

var secondList = from item in list select new MyObject
{
N = item.N,
Weight = item.N/ (from aggitem in list select item.N).Max() // or simple
list.Max(l => l.N) };

This obviously works, but it will recalculate list.Max for every item in the
list. Better to calculate it outside the LINQ expression and then reuse the
stored value inside.

 

[Pavel Minaev]

Hello,

I have a List<MyObject> where MyObject has two properties: N (int) and
Weight (int).

In this list only the N is defined for each tag.

I want to calculate the Weight for each MyObject in the list, as
follows:

Weight of MyObject = N of Tag / Maximum N of all MyObject in list

How can I do this using a Linq expression?

You don't. LINQ takes one sequence as input, and produces another new
sequence at the output. From your description, you want to mutate the values
in-place, and within the same List - in which case foreach is the best tool
for the job here (though you could still use Enumerable.Max() to calculate
the maximum N first).

 

[Alex Meleta]

Hi Pavel,

Sure, mate. But we're just talking about the way, regardless of best one

Regards, Alex Meleta
mailto:[email protected]; blog:devkids.blogspot.com