# fin_interest: Compute the value of a principal & annual deposits at a... In umx: Structural Equation Modeling and Twin Modeling in R

 fin_interest R Documentation

## Compute the value of a principal & annual deposits at a compound interest over a number of years

### Description

Allows you to determine the final value of an initial `principal` (with optional periodic `deposits`), over a number of years (`yrs`) at a given rate of `interest`. Principal and deposits are optional. You control compounding periods each year (n) and whether deposits occur at the beginning or end of the year. The function outputs a nice table of annual returns, formats the total using a user-settable currency `symbol`. Can also `report` using a web table.

notes: Graham valuation: fair P/E = 9 + (1.5 * growth%). e.g. \$INTEL fair P/E = 9+.53 = 10.5 up to 9+210 = 29 Can move the weighting between a conservative .5 and an optimistic 2 (in terms of how long the growth will last and how low the hurdle rate is)

### Usage

``````fin_interest(
principal = 0,
deposits = 0,
inflate = 0,
interest = 0.05,
yrs = 10,
final = NULL,
n = 12,
when = "beginning",
symbol = NULL,
largest_with_cents = 0,
baseYear = as.numeric(format(Sys.time(), "%Y")),
table = TRUE,
report = c("markdown", "html")
)
``````

### Arguments

 `principal` The initial investment at time 0. `deposits` Optional periodic additional investment each year. `inflate` How much to inflate deposits over time (default = 0) `interest` Annual interest rate (default = .05) `yrs` Duration of the investment (default = 10). `final` if set (default = NULL), returns the rate required to turn principal into final after yrs (principal defaults to 1) `n` Compounding intervals per year (default = 12 (monthly), 365 for daily) `when` Deposits made at the "beginning" (of each year) or "end" `symbol` Currency symbol to embed in the result. `largest_with_cents` Default = 0 `baseYear` Default = current year (for table row labels) `table` Whether to print a table of annual returns (default TRUE) `report` "markdown" or "html",

### Value

• Value of balance after yrs of investment.

### References

• `umx_set_dollar_symbol()`, `fin_percent()`, `fin_NI()`, `fin_valuation()`

Other Miscellaneous Functions: `deg2rad()`, `fin_JustifiedPE()`, `fin_NI()`, `fin_percent()`, `fin_ticker()`, `fin_valuation()`, `rad2deg()`, `umxBrownie()`

### Examples

``````## Not run:
# 1. Value of a principal after yrs years at 5% return, compounding monthly.
# Report in browser as a nice table of annual returns and formatted totals.
fin_interest(principal = 5000, interest = 0.05, rep= "html")

## End(Not run)

# Report as a nice markdown table
fin_interest(principal = 5000, interest = 0.05, yrs = 10)

umx_set_dollar_symbol("£")
# 2 What rate is needed to increase principal to final value in yrs time?
fin_interest(final = 1.4, yrs=5)
fin_interest(principal = 50, final=200, yrs = 5)

# 3. What's the value of deposits of \$100/yr after 10 years at 7% return?
fin_interest(deposits = 100, interest = 0.07, yrs = 10, n = 12)

# 4. What's the value of \$20k + \$100/yr over 10 years at 7% return?
fin_interest(principal= 20e3, deposits= 100, interest= .07, yrs= 10, symbol="\$")

# 5. What is \$10,000 invested at the end of each year for 5 years at 6%?
fin_interest(deposits = 10e3, interest = 0.06, yrs = 5, n=1, when= "end")

# 6. What will \$20k be worth after 10 years at 15% annually (n=1)?
fin_interest(deposits=20e3, interest = 0.15, yrs = 10, n=1, baseYear=1)
# \$466,986

# manual equivalent
sum(20e3*(1.15^(10:1))) # 466985.5

# 7. Annual (rather than monthly) compounding (n=1)
fin_interest(deposits = 100, interest = 0.07, yrs = 10, n=1)

# 8 Interest needed to increase principal to final value in yrs time.
fin_interest(principal = 100, final=200, yrs = 5)

``````

umx documentation built on Nov. 17, 2023, 1:07 a.m.