_0e-calc-dist-to-mrt.Rmd

```{r}
source("misc/load_libraries.R")
```


```{r}
transactions_geocoded <- read_rds("data/intermediate/transactions_geocoded.RDS")
mrt_coords <- read_rds("data/intermediate/mrt_coords.RDS")
```

```{r}
transactions_geocoded <- transactions_geocoded %>% 
    mutate(sale_date = dmy(sale_date))
```


```{r}
mrt <- map2(mrt_coords$lon, mrt_coords$lat, c)
dist_to_mrt <- function(lat1, lon1, sale_date) {
    distances <- map(mrt, distHaversine,  c(lon1, lat1))
    distances_df <- mrt_coords %>% 
        mutate(dist = distances) %>% 
        filter(opening_date <= sale_date) %>% 
        unnest(dist) %>% 
        summarise(result = min(dist))
    return(distances_df$result[1] / 1000)
}
```

```{r}
start <- Sys.time()
transactions_with_distances <- transactions_geocoded %>% 
    mutate(ctrl_dist_mrt = pmap(list(lat, lon, sale_date), dist_to_mrt)) %>% 
    unnest(ctrl_dist_mrt)
end <- Sys.time()
time_taken <- end - start
print(str_c("Time taken: ", end - start, "s"))
transactions_with_distances
```


```{r}
transactions_with_distances %>% write_rds("data/intermediate/transactions_with_dist_mrt.rds")
```