In mdsumner/splat: Bin Point Samples in Sparse Grids

knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>",
  fig.path = "README-"
)

knitr::opts_chunk$set(echo = TRUE)
library(raster)
library(splat)
library(rbenchmark)
library(dplyr)

R Markdown

load("bulkdata/082_WI_MARCH2013fitSST.RData")
#load("bulkdata/19747_WI_DEC2011fitSST.RData")
library(raster)
library(splat)
library(rbenchmark)
library(dplyr)



benchmark(
  Pimage = {px <- SGAT::Pimage(fit, type = "primary", proj = NULL)}, 
  splat = {sx <- splat(fit)}, 
  replications = 1)


format(as.numeric(object.size(px) / object.size(sx)))


r0 <- px[] * 0
imgsp <- function(x) {
  suppressMessages(xx <- tally(x %>% group_by(cell)))
  r0[xx$cell] <- xx$n
  r0
} 
imgsp2 <- function(x) {
  suppressMessages(xx <- x %>% group_by(cell) %>% summarize(n = sum(bin)))
  r0[xx$cell] <- xx$n
  r0
} 

benchmark(PimageRaster = {pall <- px[]}, 
          splatRaster = {sall  <- imgsp2(sx)}, 
          replications  = 10)

# plot(sqrt(pall), col = palr::sstPal(100))
# plot(sqrt(sall), col = palr::sstPal(100))

library(profr)
tx <- profr(x<-  SGAT::Pimage(fit, type = "primary", proj = NULL))
tsx <- profr(sx <- splat(fit))
op <-  par(mfrow = c(2, 1))
plot(tx)
plot(tsx)
par(op)

library(dplyr)

g <- setValues(x[], NA_real_)
g1 <- g
system.time({
  sgg <- sx$pix  %>% group_by(cell) %>% summarize(bin = sum(bin))
  g1[sgg$cell] <- sgg$bin
})

system.time({
  g2 <- x[]
})

## much simpler and almost as fast
g <- SGAT:::.chaingrid(SGAT::chainCollapse(fit$x))
g1 <- g
system.time({
x <- splatchain(g, SGAT::chainCollapse(fit$x))
xs <- x  %>% group_by(cell)  %>%  summarize(bin = sum(bin))
g1[xs$cell] <- xs$bin
})
system.time({
g2 <- SGAT::Pimage(fit, grid = g)[]
})