# ActuaryUtilities

## Quickstart

cfs = [5, 5, 105]
times = [1, 2, 3]
discount_rate = 0.03
present_value(discount_rate, cfs, times) # 105.65
duration(Macaulay(), discount_rate, cfs, times) # 2.86
duration(discount_rate, cfs, times) # 2.78
convexity(discount_rate, cfs, times) # 10.62

## Features

A collection of common functions/manipulations used in Actuarial Calculations.

### Financial Maths

`duration`

:- Calculate the
`Macaulay`

,`Modified`

, or`DV01`

durations for a set of cashflows - Calculate the
`KeyRate(time)`

(a.k.a.`KeyRateZero`

)duration or`KeyRatePar(time)`

duration

- Calculate the
`convexity`

for price sensitivity- Flexible interest rate models via the
`FinanceModels.jl`

package. `internal_rate_of_return`

or`irr`

to calculate the IRR given cashflows (including at timepoints like Excel's`XIRR`

)`breakeven`

to calculate the breakeven time for a set of cashflows`accum_offset`

to calculate accumulations like survivorship from a mortality vector`spread`

will calculate the spread needed between two yield curves to equate a set of cashflows

### Risk Measures

- Calculate risk measures for a given vector of risks:
`CTE`

for the Conditional Tail Expectation`VaR`

for the percentile/Value at Risk`WangTransform`

for the Wang Transformation`ProportionalHazard`

for proportional hazards`DualPower`

for dual power measure

### Insurance mechanics

`duration`

:- Calculate the duration given an issue date and date (a.k.a. policy duration)

### Typed Rates

- functions which return a rate/yield will return a
`FinanceCore.Rate`

object. E.g.`irr(cashflows)`

will return a`Rate(0.05,Periodic(1))`

instead of just a`0.05`

(`float64`

) to convey the compounding frequency. This is compatible across the JuliaActuary ecosystem and can be used anywhere you would otherwise use a simple floating point rate.

A couple of other notes:

`rate(...)`

will return the scalar rate value from a`Rate`

struct:

```
julia> r = Rate(0.05,Periodic(1));
julia> rate(r)
0.05
```

- You can still pass a simple floating point rate to various methods. E.g. these two are the same (the default compounding convention is periodic once per period):

discount(0.05,cashflows)
r = Rate(0.05,Periodic(1));
discount(r,cashflows)

- convert between rates with:

r = Rate(0.05,Periodic(1));
convert(Periodic(2), r) # convert to compounded twice per timestep
convert(Continuous(2),r) # convert to compounded twice per timestep

For more on Rates, see FinanceCore.jl. FinanceModels.jl also provides a rich and flexible set of yield models to use.

## Documentation

Full documentation is available here.

## Examples

### Interactive, basic cashflow analysis

See JuliaActuary.org for instructions on running this example.

## Useful tips

Functions often use a mix of interest_rates, cashflows, and timepoints. When calling functions, the general order of the arguments is 1) interest rates, 2) cashflows, and 3) timepoints.