SSRS - Pass Field Value List To Custom Function Assembly And Display Result

Question

I have written a SQL Server Reporting Services custom function as a C# assembly DLL and added it to my report. The purpose of the function is to search for outlier records in a collection of data. The data is represented as an array of floating point -tuplets
(float[][]). In a medical patient database, these might be things such as blood pressure, cholesterol, hight, weight, waist measurement, etc.
Several user input parameters are provided in the report, including numeric seed values for this particular algorithm. One multivalued parameter is a list of the numeric columns to be used as input to the algorithm because, importantly,
the user can choose any subset of the value columns. I have a tablix that will display columns from the dataset conditionally, based on which of those columns are chosen.
At this point, there are two issues I'm having difficulty with:
How do I, in the course of running the report, take just the numeric columns that the user has chosen (ignoring all others in the dataset) and pass them as a float[][] to my custom function? Or is there something in the
Microsoft.ReportingServices namespace that I should use to query an input dataset and convert it to an array in my C# code?
How can I present the array subset returned by my custom function in a tablix in the report?
Note: One thought that occurs to me is that outlier records tablix could be contained in a subreport, but I'm not clear on the logistics of passing dataset field results from a master report to a subreport.
I envision a final report when run to be similar to the following:
- Mark Z.

Answer 1

Hi Mark,
Sorry for the delay.
From your description, you want to pass the dataset data to a custom code array, and return the subset of the array, right? In this case, you can use a custom function to add the data to array, and use the a custom function to sort the data base on your
requirement and then use a function to get the subset of the array. Here are some sample custom code for your reference.
Add to arryay
Dim values As System.Collections.ArrayList=New System.Collections.ArrayList()
Function SetText(ByVal value As Integer) As Integer
    values.Add(value)
    return value
End Function
Sort array
Function Sort()
Dim i as Integer
Dim j as Integer
Dim t as Integer
Dim n as Integer=values.Count-1
For i=n To 1 Step-1
 For j=0 To i-1
 if values(j)<values(j+1) Then
    t=values(j)
    values(j)=values(j+1)
    values(j+1)=t
 End if
 Next j
Next i
End Function
Return value.
Function Rank(ByVal value As Integer)
   return values(value)
End Function
Assume that you pass [Weight] field to array, you can use the expression below on the Weight column:
=Code.SetText(Fields!Weight.Value)
Then use the expression below to get the values.
PatientID:=Sort() & Lookup(Code.Rank(0),Fields!Weight.Value,Fields.Patient.Value,"Dataset")
Height:=Lookup(Code.Rank(0),Fields!Weight.Value,Fields.Height.Value,"Dataset")
Weight:=Code.Rank(0)
Hope this helps.
Regards,
Charlie Liao
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