I need to fit some data to a sine to the fourth and I can’t get a user defined option in excel (or maybe I’m blind?) - Any of you guys know how to do it or know of any freeware programs that can do the same?

Thanks!

I need to fit some data to a sine to the fourth and I can’t get a user defined option in excel (or maybe I’m blind?) - Any of you guys know how to do it or know of any freeware programs that can do the same?

Thanks!

If you need the model in the form of y = a (sin x)^4 + b you can simply plot y vs (sin x)^4 , but if you want a model in the form of y = a(sin wx + phi)^4 +b that is hard. Will this help: http://forums.ni.com/ni/board/message?board.id=170&message.id=236070