saltClass=function(ec,ph,esp){
  ec=ec*1
  esp=esp*1
  ph=ph*1
  bb1=ifelse(negData("esp",esp)<15,4,13)
  bb2=ifelse(negData("esp",esp)<15,14,5)
  saltClass=ifelse(negData("ec",ec)<4,bb1,bb2)
  return(salinity=saltClass)
}
