AIS_..dimension::Compute() ..... donot have any code to compute dimension

hi
from last few dayz i was trying to display dimentions..

i have tried diffnt methods specially AIS_..Dimention

like AIS_LengthDimention method...i was able to creat object for it but not able to display it... then i found that there is a function call 'Compute()' need to call use prasentation object to display but it was not working.... there is only one public compute method and other are private so i ve been to AIS_LengthDimention.cxx file there i ve found i calcuates all stuff for private method

but for public method which we can call is called again from PrsMgr_PresentableObject class...
when i got to PrsMgr_PresentableObject.cxx file it do not have any code written there and raise a error and print no method written....

this means there not at all any method to display dimentions... this happened with all AIS_...Dimention

isnt there any method to compute n display dims????

i ve tried DsgPrs_LengthDimention it works but too slow n even make app too heavy...

any soln..... or there beings another method to display dims????