R/functions_internal_simplifyPoints.R

In avisserquinn/OSMtidy: OSMtidy is an R package for anyone who needs to tidy Open Street Map data into a concise yet complex geospatial dataset with a consistent naming convention.

simplifyPoints <- 
  function(input, descNew = NA, distance = 1000, maxIterations = 100) {
    
    distance <- units::set_units(distance, "m")
    
    iI <- st_is_within_distance(input, input, 
                                units::set_units(distance, "m"))
    iL_n <- lengths(iI)
    
    iI <- iI[order(iL_n, decreasing = TRUE)]
    
    output <- list()
    
    input2 <- input %>% st_as_sf() %>% st_make_valid()
    
    for (i in 1:maxIterations) {
      
      check <- input %>% slice(iI[[1]])
      
      if (any(str_detect(check$desc, 
                         "Exhibition centres; Stadiums and arenas") == TRUE)) {
        descN <- "Exhibition centres; Stadiums and arenas"
      }
      
      else if (any(str_detect(check$desc, 
                              "Exhibition centres; Conference centres") == TRUE)) {
        descN <- "Exhibition centres; Conference centres"
      }
      
      else if (any(str_detect(check$desc, 
                              "Exhibition centres; Events venue") == TRUE)) {
        descN <- "Exhibition centres; Events venue"
      }
      
      else if (any(str_detect(check$desc, "Exhibition centres; Ice rink") == TRUE)) {
        descN <- "Exhibition centres; Ice rink"
      }
      
      else if (any(str_detect(check$desc, "Wastewater") == TRUE)) {
        descN <- "Wastewater; Treatment works and facilities"
      }
      
      else if (any(str_detect(check$desc, "Water") == TRUE)) {
        descN <- "Water; Treatment works and facilities"
      }
      
      else if (any(str_detect(check$desc, "Pumping station") == TRUE)) {
        descN <- "Buildings; Pumping station"
      }
      
      else {
        print("No preset descNew has been found for this object type. Ensure you have specified a descNew argument.")
        descN <- descNew
      }
      
      if (nrow(check) > 1 & 
          sum(str_detect(check$type, "POLYGON")) >= 1 & 
          sum(str_detect(check$type, "POINT")) >= 1) {
        output[[i]] <- 
          input %>% slice(iI[[1]]) %>% dplyr::filter(!str_detect(type, "POINT")) %>% 
          summarise() %>% mutate(desc = descN)
      }
      
      else {
        
        if (sum(str_detect(check$type, "POINT")) == nrow(check)) {
          output[[i]] <- 
            input %>% slice(iI[[1]]) %>% mutate(desc = descN)
        }
        
        else {
          output[[i]] <- 
            input %>% slice(iI[[1]]) %>% summarise() %>% mutate(desc = descN)
        }
      }
      
      remove <- 
        which(sapply(1:length(iI), function(x) {
          iI[[x]] %in% iI[[1]] %>% sum
        }
        ) > 0)
      
      input2 <- input2 %>% slice(-iI[[1]])
      
      iI <- iI[-remove]
      
      if (length(iI) == 0) 
        break
      
    }
    
    output <- output %>% .bind_rows_sf() %>% select(desc, geometry)
    
    return(output)
    
  }