R/demog_long.R

In davewutchiett/nets_demo_spatial_dynamics: Predicting Change and Modeling Relationships In NYC Local Retail and Population.

#' Transform census variables to long form 
#' where variable names are concatinated descriptor & two digit decade integer
#' @export

demog_long = function(d = df, t = t_var, ids = id, vars = demographics){
  t.i = unique(d[ ,t])
  t.i.abrev = substr(t.i, nchar(t.i) - 1, nchar(t.i))
  n = nrow(d)
  p = length(demographics) / length(t.i) + 2 
  d.out = as.data.frame(mat.or.vec(nr = n, nc = p))
  for (j in 1:length(t.i)){
    d.t = d[ d[,t] == t.i[j], ]
    t_set = t.i.abrev[j]
    if (t_set == '10'){
      t_set = paste(t_set, '0a', sep = '|')
      }
    t_var_indices = grep(t_set, vars)
    v.set = d.t[ ,vars][ ,t_var_indices]
    v.names = colnames(v.set)
    common_names = gsub(t_set, "", v.names)
    v.set.out = cbind(v.set, d.t[ ,c(t, ids)])
    colnames(v.set.out) = c(common_names, t, ids)
    n_d.t = nrow(d.t)
    rows = (((j - 1) * n_d.t) + 1):(j * n_d.t)
    d.out[rows,] = v.set.out
    colnames(d.out) = colnames(v.set.out)
  }
  return(d.out)
}