From: flebber Date: 2010-11-07T07:50:14+09:00 Subject: Re: Create a class - ideas On Nov 7, 2:24 am, Robert Klemme wrote: > On 06.11.2010 10:19, flebber wrote: > > > I am trying to create a class. I am struggling to figure the best flow > > to get the maths side to work. > > > So say that > > > R is a float given by user input > > P is a Total amount(Pool) > > Per is a variable % > > X is a variable that is a percentage of P defined by a maximum > > allocation. > > > So main = (( R * X)/P)*100 > > First of all you should get your variables right.  Variable "Per" does > not show up in the formula and "main" is not mentioned in the list. > > The meaning of the formula is totally unclear to me.  From what you gave > you are calculating the fraction (R/P) multiply it with 100 (so you > actually get (R/P) percent and now you multiply with another percentage > (X).  So you have a percentage of a percentage. > > > What I want to test is the value of X needed to equal Per from X's > > maximum allocation down. > > Can you write down a formula that contains all variables in your list > and point at the fixed ones (constants), user inputs and variables you > want to resolve? > > > > > > > > > > > What i am thinking but cant get right > > > Say > > > R = 5 > > P = 10 > > Per = 190 > > X = max 80% of P > > > For X in main = Per ( Closest whole number or half that equals closest > > to but greater than Per) > > main = (( 5 * 8)/10)*100 > > > So in example intially main equalled 400%. And answer I would want to > > resolve it to is X = 4 which is 200% as 3.50 equals 180%. > > > Any ideas? > > Sorry you lost me somewhere along the path.  Also it's tea time right now... > > Cheers > >         robert > > -- > remember.guy do |as, often| as.you_can - without endhttp://blog.rubybestpractices.com/ So I want to check by changing X when in forumla "main" that it is => than "per" In simple terms I want to calculate units needed to reach a rate of return, X represents the variable units and per is the ROI(return of investment rate I would deaire to acheive), R is the ratio of return and P is a pool or base amount, I am using base 10 to start off with. I am trying to test X for a value, the only constraint on X is that it cannot exceed 80% of the P or Pool amount. So if I set per = 190% R = 5 P = 10 Per = 190 X = max 80% of P For X in main >= per main = (( 5 * X)/10)*100 >= 190% so for X = 80% of P or 8 base units main = (( 5 * 8)/10)*100 which would test out as main >= per 400 => 190 - So when X is 8 units the main section is greater than per but its not the closest whole unit to per. So when X = 40% or 4 base units main = (( 5 * 4)/10)*100 main >= per 200 >= 190 this is the largest unit in 0.5 increments that remains greater than Per of 190 so I would want X once tested to resolve to this. I hope that made sense.