Modern Finance SolveRatePerPeriod

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SolveRatePerPeriod

Returns the rate per period implied by a known payment, value and term.

Syntax

SolveRatePerPeriod( annuityTerms )
SolveRatePerPeriod( annuityTerms, solverOptions )

Examples

#import "std/money"
using money

'' The rate implied by a known payment -- the one function on this
'' surface that iterates, because there is no closed form for i.
dim as Decimal i = RatePerPeriod( DecimalParse( "0.0595" ).Value( ), COMPOUND_MONTHLY ).Value( )

dim as AnnuityTerms m = AnnuityTermsMake( i, 360, DecimalZero( ), _
                                          DecimalParse( "400000" ).Value( ), _
                                          DecimalZero( ), PAY_END_OF_PERIOD )
dim as Decimal pmt = PaymentAmount( m ).Value( )

'' Feed the payment back and the rate comes out again.
dim as AnnuityTerms back = AnnuityTermsMake( DecimalZero( ), 360, pmt, _
                                             DecimalParse( "400000" ).Value( ), _
                                             DecimalZero( ), PAY_END_OF_PERIOD )
print ( SolveRatePerPeriod( back ).Value( ).Round( 12 ) = i.Round( 12 ) )    '' true

'' A 0% loan solves to EXACTLY zero rather than to something tiny.
dim as AnnuityTerms z = AnnuityTermsMake( DecimalZero( ), 24, _
                                          DecimalParse( "-100" ).Value( ), _
                                          DecimalParse( "2400" ).Value( ), _
                                          DecimalZero( ), PAY_END_OF_PERIOD )
print SolveRatePerPeriod( z ).Value( ).IsZero( )                             '' true

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Library: Finance
Category: Finance
Documented under: Nothing Becomes A Keyword
Source: pkg/std/money/fintvm.tiko in the tiko repository.