Linq Extension Methods for aggregate RSS

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  jayakumarvin...

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  Linq Extension Methods for aggregate

  Dec 10, 2018 10:51 AM|jayakumarvinayagam|LINK

  Hai All,

  How we extend the percentage function to calculate the percentage of its items.

  Example:

  Id	Name	Phone	Address
  1001	AAAAAAAAA	1234567890	XXXXXXXXXXXX
  	BBBBBBBBBB	1234567891
  1003	CCCCCCCCCC	1234567892
  1004		1234567893	VVVVVVVVVVVVVV

  Find the percentage about each property in the container.

  Total: 4

  Id:  75%

  Name = 75%

  Phone: 100%

  Address: 50% => (address / (decimal)total) * 100,

  I used to find the number of it available in list and calculate the percentage once by one, there is any other way to calculate the percentage by using generic extension methods.

  Thanks,

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  mgebhard

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  Re: Linq Extension Methods for aggregate

  Dec 10, 2018 01:35 PM|mgebhard|LINK

  jayakumarvinayagam

  I used to find the number of it available in list and calculate the percentage once by one, there is any other way to calculate the percentage by using generic extension methods.

  The Enumerable type has a average method.

  https://docs.microsoft.com/en-us/dotnet/api/system.linq.enumerable.average?view=netframework-4.7.2

  All you need to do is pass the column collection to the Average method.  

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  Ackerly Xu

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  Re: Linq Extension Methods for aggregate

  Dec 11, 2018 06:11 AM|Ackerly Xu|LINK

  Hi jayakumarvinayagam,

  You could use linq where clause so that you don't need to loop through the data.

  Below is my code.

   protected void Page_Load(object sender, EventArgs e)
          {
              DataTable table = new DataTable();
              table.Columns.Add(new DataColumn("id", typeof(Int32)));
              table.Columns.Add(new DataColumn("Name", typeof(string)));
              table.Columns.Add(new DataColumn("Phone", typeof(string)));
              table.Columns.Add(new DataColumn("Address", typeof(string)));
              table.Rows.Add(1001, "AAA", "1234", "XXX");
              table.Rows.Add(DBNull.Value, "BBB", "1234", DBNull.Value);
              table.Rows.Add(1003, "CCC", "1234", DBNull.Value);
              table.Rows.Add(1004, DBNull.Value, "1234", "XXX");
                               //chanage datatable to enumerable so that linq could be used and use where to filter the data
                            //r["id"] != DBNull.Value is a boolean , and linq will return the record when it is true
              double percentId = (double)table.AsEnumerable().Where(r =>  r["id"] != DBNull.Value).Count() / table.Rows.Count;
  
              double percentName = (double)table.AsEnumerable().Where(r => r["Name"] !=DBNull.Value).Count() / table.Rows.Count;
              double percentPhone = (double)table.AsEnumerable().Where(r => r["Phone"] != DBNull.Value).Count() / table.Rows.Count;
              double percentAddress = (double)table.AsEnumerable().Where(r => r["Address"] != DBNull.Value).Count() / table.Rows.Count;
            
             
              Response.Write("total:" + table.Rows.Count + "<br/>");
              Response.Write("id:" + string.Format("{0:0%}", percentId )+"<br/>");
              Response.Write("name:" + string.Format("{0:0%}", percentName ) + "<br/>");
              Response.Write("phone:" + string.Format("{0:0%}", percentPhone ) + "<br/>");
              Response.Write("address:" + string.Format("{0:0%}", percentAddress ) + "<br/>");
  
  
          }

  The result.

  

  Best regards,

  Ackerly Xu

  MSDN Community Support
  Please remember to click "Mark as Answer" the responses that resolved your issue.
  If you have any compliments or complaints to MSDN Support, feel free to contact MSDNFSF@microsoft.com.
• • Reply
  jayakumarvin...

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  Re: Linq Extension Methods for aggregate

  Dec 11, 2018 07:47 AM|jayakumarvinayagam|LINK

  That's good, am looking to a more generic way to handle percentage, because in my scenario that specific logic used more than one collection that's the reason am planning to implement generic/extends the percentage.

   

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  Ackerly Xu

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  1300 Posts

  Re: Linq Extension Methods for aggregate

  Dec 12, 2018 01:38 AM|Ackerly Xu|LINK

  Hi  Jayakumar Vinayagam,

  You could encapsulate a method of your own, for example.

  private string MyExtend(DataTable table)
          {
              string str = "";
              str += "total:"+table.Rows.Count+"<br/>";
          
              foreach (DataColumn item in table.Columns)
              {
                  string name = item.ColumnName;
                  double percent = (double)table.AsEnumerable().Where(r => r[item] != DBNull.Value).Count() / table.Rows.Count;
                  str += name + ":" + string.Format("{0:0%}",percent) + "<br/>";
              }
              return str;
          }

  Best regards,

  Ackerly Xu

  MSDN Community Support
  Please remember to click "Mark as Answer" the responses that resolved your issue.
  If you have any compliments or complaints to MSDN Support, feel free to contact MSDNFSF@microsoft.com.