rajesh hamal jee, i am at it now. hope it will go through well. thanks again for your help. i have also sent an email through sajha. Hussain_Khan jee, my major is in civil engineering and it is related to surrogate-type modeling for the effect of ice regime on arctic structures based on >10 yrs of observed data. fortunately, looks like the suggestion by rajesh hamal is working well. earlier i had tried to use the GNU math library but i never understood the C-pointers- anyway, its going good for now. mickey mouse jee, thanks for the goodwill, looks like i got the help. timetraveller jee, it is in the univ for the project of my employer+supervisor thanks everyone again, Keep rolling...