R/get_aggregation_last.R

In rasterly: Easily and Rapidly Generate Raster Image Data with Support for 'Plotly.js'

get_aggregation.last <- function(plot_width, plot_height, aesthetics,
                                 x_range, y_range, xlim, ylim, 
                                 func, glyph, group_by_data_table, ...) {
  
  if(is.null(aesthetics$on)) stop("No `on` argument was provided. Which variable should be used to specify the last value encountered for aggregation?")
  is_size <- !is.null(aesthetics$size)
  is_color <- !is.null(aesthetics$color)
  
  L <- if(group_by_data_table) {
    
    display <- aesthetics[,
                          list(
                            display = list(
                              aggregation_lastCpp(plot_width = plot_width, plot_height = plot_height,
                                                  x_range = x_range, y_range = y_range,
                                                  xlim = xlim, ylim = ylim,
                                                  x = x,
                                                  y = y,
                                                  on = on,
                                                  size = if(is_size) size else numeric(0),
                                                  glyph = glyph)
                            )
                          ),
                          by = if(is_color) color else NULL]
    remove(aesthetics)
    display$display
  } else {
    
    if(is_color) {
      levels <- unique(aesthetics$color)
      # agg_sumCpp return a list
      agg_lastCpp(L = lapply(1:length(levels), function(i) matrix(0, nrow = plot_height, ncol = plot_width)),
                  levels = levels,
                  category = aesthetics$color,
                  plot_width = plot_width, plot_height = plot_height,
                  x_range = x_range, y_range = y_range,
                  xlim = xlim, ylim = ylim,
                  x = aesthetics$x,
                  y = aesthetics$y,
                  on = aesthetics$on,
                  size = if(is_size) aesthetics$size else numeric(0),
                  glyph = glyph)
    } else {
      list(
        aggregation_lastCpp(plot_width = plot_width, plot_height = plot_height,
                            x_range = x_range, y_range = y_range,
                            xlim = xlim, ylim = ylim,
                            x = aesthetics$x,
                            y = aesthetics$y,
                            on = aesthetics$on,
                            size = if(is_size) aesthetics$size else numeric(0),
                            glyph = glyph)
      )
    }
  }
  return(L)
}