Subset time series based on their position within an mts_monitor object

An mts_monitor object is reduced so as to contain only the first or last n timeseries. These functions work similarly to dplyr::slice_head and dplyr::slice_tail but apply to both dataframes in the mts_monitor object.

This is primarily useful when the mts_monitor object has been ordered by a previous call to monitor_arrange or by some other means.

monitor_slice_head() selects the first and monitor_slice_tail() the last timeseries in the object.

monitor_slice_head(monitor, n = 5)

monitor_slice_tail(monitor, n = 5)

Arguments

monitor: mts_monitor object.
n: Number of rows of monitor$meta to select.

Value

A subset of the incoming mts_monitor time series object. (A list with meta and data dataframes.)

Examples

library(AirMonitor)

# Find lowest elevation sites
Camp_Fire %>%
  monitor_filter(!is.na(elevation)) %>%
  monitor_arrange(elevation) %>%
  monitor_slice_head(n = 5) %>%
  monitor_getMeta() %>%
  dplyr::select(elevation, locationName)
#> # A tibble: 5 × 2
#>   elevation locationName           
#>       <dbl> <chr>                  
#> 1      0.9  San Rafael             
#> 2      0.9  Redwood City           
#> 3      1.5  San Francisco          
#> 4      2.21 Calexico - Ethel Street
#> 5      2.7  Oakland West           

# Find highest elevation sites
Camp_Fire %>%
  monitor_filterMeta(!is.na(elevation)) %>%
  monitor_arrange(elevation) %>%
  monitor_slice_tail(n = 5) %>%
  monitor_getMeta() %>%
  dplyr::select(elevation, locationName)
#> # A tibble: 5 × 2
#>   elevation locationName    
#>       <dbl> <chr>           
#> 1     1917. Tahoe City      
#> 2     2055. Lee Vining      
#> 3     2291  MMNPS1033       
#> 4     2306. Devil's Postpile
#> 5     2646. MMFS10401