1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
extern crate round;
use round::round;
pub fn present_value(rate: f64, compounding_periods: f64, future_value: f64) -> f64 {
let discount_factor: f64 = 1. + rate;
future_value / (discount_factor.powf(compounding_periods))
}
#[test]
fn test_present_value() {
let test_value = present_value(0.1, 1., 1000.);
assert_eq!( round(test_value, 2), 909.09);
}
pub fn future_value(rate: f64, compounding_periods: f64, present_value: f64) -> f64 {
let compound_factor: f64 = 1. + rate;
present_value * (compound_factor.powf(compounding_periods))
}
#[test]
fn test_future_value() {
let test_value = future_value(0.1, 1., 1000.);
assert_eq!( round(test_value, 2), 1100.00);
}
pub fn net_present_value(rate: f64, cfs: &[f64]) -> f64 {
let discount_factor = 1. + rate;
let mut npv: f64 = 0.;
for n in 0..cfs.len() {
npv += cfs[n] / discount_factor.powf(n as f64);
}
npv
}
#[test]
fn test_net_present_value() {
let test_npv = net_present_value(0.1, &[-1000., 500., 500., 500.]);
assert_eq!(round(test_npv, 2), 243.43);
}
pub fn payment(present_value: f64, number_of_compounding: f64, rate: f64) -> f64 {
present_value / ( (1. - (1. / (1. + rate).powf(number_of_compounding)) ) / rate )
}
#[test]
fn main () {
let test_value = payment(190000., 30.0, 0.08);
assert_eq!(round(test_value, 2), 16877.21);
}
pub fn periodic_interest_rate(annual_percentage_rate: f64, number_of_compounding: f64) -> f64 {
annual_percentage_rate / number_of_compounding
}
#[test]
fn test_periodic_interest_rate() {
let test_value = periodic_interest_rate(0.10, 4.);
assert_eq!(round(test_value, 3), 0.025);
}
pub fn holding_period_return(profit: f64, cost: f64) -> f64 {
profit / cost
}
#[test]
fn test_hpr() {
let test_value = holding_period_return(5000., 4000.);
assert_eq!(test_value, 1.25);
}
pub fn number_of_compounding(future_value: f64, present_value: f64, rate: f64) -> f64 {
(future_value / present_value).ln() / (1. + rate).ln()
}
#[test]
fn test_number_of_compounding() {
let test_value = number_of_compounding(5000., 4000., 0.02);
assert_eq!(round(test_value, 2), 11.27);
}
pub fn return_on_investment(earnings: f64, cf0: f64) -> f64 {
(earnings - cf0.abs()) / cf0.abs()
}
#[test]
fn test_roi() {
let test_value = round( return_on_investment(5000., 4000.), 2);
assert_eq!(test_value, 0.25);
}
pub fn interest_rate(future_value: f64, present_value: f64, number_of_compounding: f64) -> f64 {
(future_value / present_value).powf( number_of_compounding.recip() ) - 1.
}
#[test]
fn test_interest_rate() {
let test_value = interest_rate(5000., 4000., 4.);
assert_eq!(round(test_value, 4), 0.0574);
}
pub fn rule_of_72(rate: f64) -> f64 {
72. / (rate * 100.)
}
#[test]
fn test_rule_of_72() {
assert_eq!( round( rule_of_72(0.035), 2) , 20.57);
}
pub fn rule_of_70(rate: f64) -> f64 {
70. / (rate * 100.)
}
#[test]
fn test_rule_of_70() {
assert_eq!( round(rule_of_70(0.035), 2) , 20.);
}
pub fn leverage_ratio(total_liabilities: f64, total_debts: f64, total_income: f64) -> f64 {
((total_liabilities + total_debts) / total_income)
}
#[test]
fn test_leverage_ratio() {
let test_ratio = leverage_ratio(1000., 2000., 4000.);
assert_eq!( round( test_ratio, 2) , 0.75);
}
pub fn weighted_cost_of_capital(market_value_of_equity: f64, market_value_of_debt: f64, cost_of_equity: f64, cost_of_debt: f64, tax_rate: f64) -> f64 {
let e = market_value_of_equity;
let d = market_value_of_debt;
let v = e + d;
let re = cost_of_equity;
let rd = cost_of_debt;
let t = tax_rate;
((e / v) * re ) + (((d / v) * rd ) * (1. - t))
}
#[test]
fn test_wacc() {
let test_value = weighted_cost_of_capital(2000000.00, 1000000.00, 0.07, 0.05, 0.4);
assert_eq!( round(test_value, 4), 0.0567);
}
pub fn effective_annual_rate(annual_rate: f64, number_of_compounding: f64) -> f64 {
(1. + (annual_rate / number_of_compounding)).powf(number_of_compounding) - 1.
}
#[test]
fn test_effective_annual_rate () {
let test = effective_annual_rate(0.05, 12.);
assert_eq!(round(test, 4), 0.0512);
}