Solve the differential equation F'(x) = E(x) with F(0)=a and F(200) = b. The solution is F(X) = c*E(x) +d. Giving two linear equations for c and d.
c = (b-a)/(E(200) - 1) d = (a*E(200) - b)/(E(200) - 1) R -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Super Steve Sent: Tuesday, 12 May 2009 12:12 PM To: NZ PHP Users Group Subject: [phpug] Exponential Values I need a bit of help with working out some maths. I have a number somewhere between 0 and 200 that I want to map onto a range between 500 and 250000. This I can do with the calculation: mapped = (value * (249500 / 200)) + 500 But now I want the mapped value to rise exponentially between 500 and 250000. I.e. in a curved exponential rise. I know PHP has the exp() function, could I somehow use this? --~--~---------~--~----~------------~-------~--~----~ NZ PHP Users Group: http://groups.google.com/group/nzphpug To post, send email to [email protected] To unsubscribe, send email to [email protected] -~----------~----~----~----~------~----~------~--~---
