cap_growth = 5
v = (@property.current_value / 100 * cap_growth) + @property.current_value
puts v
v = (v / 100 * cap_growth) + v
puts v
v = (v / 100 * cap_growth) + v
puts v
v = (v / 100 * cap_growth) + v
puts v
v = (v / 100 * cap_growth) + v
puts v
v = (v / 100 * cap_growth) + v
puts v
v = (v / 100 * cap_growth) + v
puts v
v = (v / 100 * cap_growth) + v
there must be a better way to do this.
im doing something like the code below to calculate compund interest and print the result each year
2007-09-30T12:50:38+00:00
34
Ruby
compound-interest
6
compound interest
2007-09-30T12:50:38+00:00
89
cap_growth = 5
v += (@property.current_value / 100 * cap_growth)
for i in (0..7)
puts v
v += v / 100 * cap_growth
end
34
Why don't you use a loop?
(Untested)
2007-09-30T14:05:36+00:00
137
Ruby
2
3
On compound interest
84
typefreak
cap_growth = 5
v = @property.current_value
8.times do
puts v += v/ 100 * cap_growth
end
34
Here is the same thing, a bit shorter.
2007-09-30T15:14:25+00:00
138
Ruby
3
3
On compound interest
90
anshkakashi
a = (0..8).inject([]) {|a, i| a << (v += (v/100) * cap_growth)}
34
I'm not sure what you are trying to do, but if you wanted to keep track of the values, you could do something like...
2007-09-30T16:29:08+00:00
140
Ruby
1
2
On compound interest
81
bauser
#!/usr/bin/ruby -w
#
# Using geometric series to calculate value of:
# ar^n + ar^(n-1) + ... + ar^2 + ar + a
#
# = a(1-r^(n+1))/(1-r)
#
# also adding a starting savings to get:
#
# a(1-r^(n+1))/(1-r) + sr^n
#
puts "Enter Starting Amount"
s = gets.chomp.to_f
puts "Enter savings per year"
a = gets.chomp.to_f
puts "Enter savings rate of return"
r = gets.chomp.to_f
puts "Enter number of years"
n = gets.chomp.to_f
value = a*(1-r**(n+1))/(1-r) + s*r**n
value = (value*100).round / 100.0
puts "Saved: $#{value} in #{n} years"
34
Using a simple formula to calculate the final value. Not useful for every value, but does jump right to the end without looping.
2007-10-01T07:45:49+00:00
151
Ruby
5
1
On compound interest
jtm
class Investment < Struct.new(:start_year, :start_value, :interest_rate)
def value_at(year)
start_value * (1 + interest_rate) ** (year - start_year)
end
end
# # Sample usage
# we invest 100 in 1990 at 5% interest and want to know the value per
# every year from 1990 to 2005
i = Investment.new(1990, 100, 0.05)
(1990..2005).each { |year| puts i.value_at(year) }
34
This is just an example on how you can wrap the calculation in a class.
one method provide the calculation of the value at any time in the future.
2007-10-01T09:38:19+00:00
153
Ruby
4
3
On compound interest
95
hungryblank