Computes interest rates for investments.

Load these functions with "load interest".

functionrate(x:vector, n:vector=none)

Compute the interest rate in % for an investment with returns. x : Vector of payments (negative) or income (positive) at evenly spaced periods or at times in the vector n. n : times of payments (default is yearly). >load interest; >rate([1000,-50,-50,-50,-50,-1050])+"%" // savings 5% >rate([-1000,0,0,0,0,1200])+"%" // accumulated interest 3.71372893366% >rate(100000|(-10150*ones(1,20))) // 20 year loan 7.95349754169 >rate([-1200,0,0,0,2100]), rate([-1200,2100],[0,4]) 15.0163316896 15.0163316895 See:

simrate (Interest Rates)

functionsimrate(v:vector, P:positive real, digits=none)

Simulates payments in vector v at rate P in % >v=simrate(100000|(-10150*ones(1,20)),7.96,2) [ 100000 97810 95445.68 92893.16 90137.46 87162.4 83950.53 80482.99 76739.44 72697.9 68334.65 63624.09 58538.57 53048.24 47120.88 40721.7 33813.15 26354.68 18302.51 9609.39 224.3 ] >columnsplot(v);

functionmap investment(start, instalment, final, n; i0=1, i1=1)

Computes the interest rate of a loan and other investments. Note that payments are negative! start: start investment at period 0 instalment: rate payed at the start of periods i0 to n-i1 (by default n-1 rates) final: that is the final dept after n periods >print(investment(1000,-50,-1050,10),2,unit="%") 5.00% >print(investment(1000,0,-1200,5),2,unit="%") 3.71% >print(investment(100000,-10150,0,21),2,unit="%") 7.95% The result is the interest rate in %. See:

rate (Interest Rates)

functionfinaldebt(loan,periods,rate,payment,start=1)

Compute the final dept of a loan after periods of payments. See:

rate (Interest Rates)