R/loadJSON.R

In jmarca/grid_data: Process CalVAD 4km grid data

parseImputeRecord <- function(rawjson){
  ## trim it down
  properties <- rawjson$features[[1]]$properties
  gridData <- properties$data
  header <- properties$header
  ncol = length(header)
  data.matrix <- matrix(unlist(gridData[1:12]),byrow=TRUE,ncol=ncol)
  colnames(data.matrix) <- header
  df <- data.frame(data.matrix)
  df[,3:17] <- apply(df[,3:17],2,as.numeric)
  df$dashts <- strptime(df$ts,"%Y-%m-%d %H:%M",tz='UTC')
}

default.header =c("ts","freeway","n","hh","not_hh","o","avg_veh_spd","avg_hh_weight","avg_hh_axles","avg_hh_spd","avg_nh_weight","avg_nh_axles","avg_nh_spd","miles","lane_miles","detector_count","detectors")

parseGridRecord <- function(rawjson){
  ## trim it down
    rows <- rawjson$rows
    df <- plyr::ldply(rows,.fun=function(x){

        ## the below stuff works, but is irrelevant right now as I am
        ## only worried about aadt_frac and timestamp.  so instead of
        ## the following, just grab one row to get the time stuff

        ## ## data is a ragged array.  build one row at a time
        ## dd <- NULL
        ## plyr::l_ply(x$doc$data,.fun=function(row){
        ##     dd <<- c(dd,unlist(row)[1:16])
        ## })
        ## dd <- matrix(dd,nrow=length(x$doc$data),byrow=TRUE)

        justtime <- unlist(x$doc$data)[1] ## should introspect here
        daadt <- unlist(x$doc$aadt_frac)
        dicell <- unlist(x$doc$i_cell)
        djcell <- unlist(x$doc$j_cell)
        c(justtime,daadt,dicell,djcell)
    })
    names(df) <- c(default.header[1],'n.aadt.frac','hh.aadt.frac','nhh.aadt.frac','i_cell','j_cell')
    df[,2:6] <- apply(df[,2:6],2,as.numeric)
    df$ts2 <- strptime(df$ts,"%Y-%m-%d %H:%M",tz='UTC')
    df$tsct <- as.POSIXct(df$ts2)
    df
}

aadt.cols <- c('n.aadt.frac','hh.aadt.frac','nhh.aadt.frac')


parseAADTRecord <- function(rawjson){
  ## just a doc, make it a df
  dfaadt <- data.frame(i_cell = rawjson$i_cell,
                   j_cell = rawjson$j_cell,
                   aadt.n = 0,
                   aadt.hh = 0,
                   aadt.nhh = 0
                   )
  ## sum these up
  plyr::l_ply(rawjson$aadt,.fun=function(x){
    dfaadt$aadt.n <<- dfaadt$aadt.n + x$n[1]
    dfaadt$aadt.hh <<-dfaadt$aadt.hh + x$hh[1]
    dfaadt$aadt.nhh <<- dfaadt$aadt.nhh + x$not_hh[1]
  })
  dfaadt
}


parseGridFile <- function(jsonfile){
  ## get it
  rawjson <- RJSONIO::fromJSON(jsonfile,simplify=FALSE)
  ## trim it down
  rows <- rawjson$features[[1]]$properties$data
  df <- plyr::ldply(rows,.fun=function(x){unlist(x)[1:16]})
  names(df) <- default.header[1:16]
  df[,3:16] <- apply(df[,3:16],2,as.numeric)
  df[,2] <- as.factor(df[,2])
  df$ts2 <- strptime(df$ts,"%Y-%m-%d %H:%M",tz='UTC')
  df$tsct <- as.POSIXct(df$ts2)
  df
}