# Time Value of Money calculator

## Performs financial calculations for:

- n (number of periods)
- pv (present value)
- pmt (payment amount)
- fv (future value)
- i (interest rate)

**NOTE:** Only supports annuity due.

## Usage

Install the gem:

```
gem install time_value
```

Initialize with values:

```
time_value = TimeValue.new(n, i, pv, pmt, fv)
```

Or set values after initialization:

```
time_value = TimeValue.new()
time_value.n = my_n
time_value.i = my_i
time_value.pv = my_pv
time_value.pmt = my_pmt
my_fv = time_value.calc_fv()
```

Remember to follow a convention for signs of values:

- Money being paid should have a negative value (-)
- Money being received should have a positive value (+)

Failing to follow this convention may yield unexpected results