earle@mahendo.Jpl.Nasa.Gov (Greg Earle) (09/25/88)
Here's a little program to compute loan payments (using the standard
equations for loan payments) based on Principal, Interest rate and length
of term (in months). Nothing that hasn't been done before; just in this
case the main workhorse is a bc(1) program instead of being written in C.
I provide this for your edification, amusement, and hopefully to show
people how flexible `bc' is. You may discover something you didn't know!
I use this all the time to figure out car loan payments for all those cars
I can't afford :^)
Here is the `loan' Bourne Shell script: (System V sites modify the `echo -n'
to `echo Mumble\c' as appropriate)
----------------------------- >8 Cut here 8< --------------------------
#!/bin/sh
echo -n Enter the amount of the Principal: ""
read P
echo -n Enter the Interest in percent: ""
read I
echo -n Enter the loan Term in months: ""
read T
echo ""
echo -n The monthly payment is \$
/usr/bin/bc << EOBC
/* 'bc(1)' program to find out the amount of an exact payment */
/* due each month for a fixed-payment-plan car loan. */
define a(i, n) {
auto z
z = (1 + i) ^ n
return(z)
}
define r(i, n) {
auto z,x
z = i * a(i,n)
z /= (a(i,n) - 1)
scale=4
x = z
return(x)
}
define m(p, i, n) {
auto y,z
scale = 10
i /= 1200
y = p * r(i, n)
scale = 2
z = y * 100
z /= 100
return(z)
}
m($P, $I, $T)
EOBC
echo ""
exit 0
--
Greg Earle earle@Sun.COM
Sun Microsystems poseur!earle@mahendo.JPL.NASA.GOV
Los Angeles Consulting earle%mahendo@elroy.JPL.NASA.GOV
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