{r setup, include=FALSE} knitr::opts_chunk$set(eval = FALSE) {r message=FALSE, warning=FALSE, include=FALSE} library(tidyverse)
估值72法则
$$1+100% = 1\times (1 + r%)^n \to n \approx \frac{72}{r}$$
{r message=FALSE, warning=FALSE, paged.print=TRUE} r <- seq(0.001,0.500,by = .001) yr_actual <- log(2)/log(1+r) yr_pred <- 72/(r*100) yr_data <- data_frame( r = r, yr_actual = yr_actual, yr_pred = yr_pred ) %>% mutate(yr_delta = yr_actual-yr_pred) yr_data %>% gather(key,value,yr_actual:yr_delta) %>% ggplot(aes(x = r, y = value, col = key)) + geom_line() + scale_y_log10() yr_data %>% mutate(leq0 = yr_delta > 0) %>% ggplot(aes(x = leq0)) + geom_bar(aes(y = ..count..))