Sign function in tableau

sign function will takes input as number if the input number is "+ve" it returns +1 ,


                                             if the input number is "-ve" it returns -1 ,

                                     
                                             if the input number is "0" it returns 0 ,



              Syntax                                    

                                 sign(number)

               Examples
                                 sign(4)=1

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Trimming functions in tableau

  In tableau 3 types of trimming functions are available.

 
        LTRIM

        RTRIM

        TRIM

LTRIM function removes the empty space from the left part of the input string.where as Rtrim removes the empty space from the right part of the string. where as Trim function eliminates empty spaces from both sides of the string.


            syntax:

             Ltrim(string)


             example:


                Ltrim(' tableau ') ='tableau '




            syntax

             Rtrim(string)


             example


                Rtrim(' tableau ') =' tableau'



         
            syntax

             Trim(string)


             example:


                trim(' tableau ') ='tableau'


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Round function in tableau

  Round function rounds the number of  places in the input number and it displays  the nearest value


         syntax :

                   Round(number,[no-of-places)



 while rounding the input number to 'n' places tableau will checks the 'n+1' values .If "N+1 value is '>=5'.in tableau will acts 1 to the n position value . if the number is less 5(<5) then it will display 'n' vale as it is.

Hierarchical filtering in tableau

 Selecting  the values in one filter if it is effecting in the other filter then such a kind of filtering is known as cascading filters this cascading filters are also known as hierarchical filters normally this cascading filters can be applied for the hierarchical data. if you  apply only relevant values on more than one filter means their filtering each other some time may resulting leads degrade the performance. so it is not good practice by applying only relevant values on two quick filters simultaneously at a time.

Calculations in tableau

   Normally each and every time in tableau it is not possible to obtain the meaningful output from the existing data field .some times we need to create the new field in the tableau known as the calculated field.this calculated fields can be obtain  by writing calculations this calculations contains data fields ,parameters,functions and optionally comments also as this calculated field are deriving from the existing data fields this calculated fields are also known as as derived fields.


   note 
 one calculated field can be used inside the second calculated field without restrictions.

Date functions in tableau

   date add function


             date add function takes the input as date and to  input date it will add the interval based on the             date part.


              syntax:

                    DATEADD(datepart,interval,input-date)
               where data part indicates month,year ,quarter ,day etc.



          example

                  Date add('month'3,,#8-nov-2014#)=8-feb-2015


       note 
             in tableau the date should be enclosed between the open# and the closed #


             in date functions always the datepart should be specified in the lowercase.



DATE DIFF


          date diff function finds the diff between two dates based on the datepart and optionally it will             takes the  'week start day also'.

 
                    syntax
                           DATEDIFF(datepart,start-date,end-date,[weeksstartday])



DATE NAME:

           the date name function takes the input as date along with the date part and it names that date                     part.


             syn

               datename('datepart',input-date,[week-start-day])


      
             
                example  datename('month',#8-nov-2014#)=nov



DATE TRUNK


              date trunk function reduce the accuracy of the input date based on the date part.


                  syn
                         datetrunc (datepart,date,[week-start-day])



                         datetrunc('month',#8-nov-2014#)=1-nov-2014



DATE PARSE


            The date parse function converts any string to the date based on the input format this function is available


            from tableau 8.2 based on the specified format tableau will convert the data.



                      syntax:


                            Dateparse(dformat,string) 



                       example

                           
                            Date parse("dd.mm.yyyy,'08.10.2014')= 8-nov-2014


 
today,now functions
         
                  today function gives the current date where as now function gives the current date+time.
       

Parameter in tableau

      All the values in the calculated field are static if you want make use of the dynamic values
        in place of static values we have to make use of a parameter .parameter will replace static value
        in the calculations, filters extra.in tableau we can create a different  types of parameters like
       string,integer,Boolean,date, extra  to the parameter based on the datatype we can add the values          manually we can add the values from field and even we can add from clipboard also.


  note:

     At a time the parameter we can select only single value multi values selection is not available.