start_api_3.R

start_api_3.R

library(randomForest)
library(jsonlite)

# wczytanie modelu
model <- readRDS("model_rf.RDS")

# API - metody
predict_iris <- function(df) {
  df <- as.data.frame(df)
  ## this is a bug in the client, it uses wrong names - so we have to fix it
  names(df) <-
    c("Sepal.Length","Sepal.Width",
      "Petal.Length","Petal.Width")

  pred <- as.character(predict(model, df))
  # The python server only responds with the prediction
  # we could spit out the whole row, if that was desired:
  #jsonlite::toJSON(cbind(df, Species=pred))
}

alive <- function()
  "I'm alive!"

add_floats <- function(a, b)
  as.numeric(a) + as.numeric(b)

.http.request <- function(path, query, body, headers) {
  what <- if (length(body)) jsonlite::fromJSON(rawToChar(body)) else list()
  ## /add abuses path as arguments...
  pc <- strsplit(path, "/")[[1]][-1]
  as.character(switch(pc[1],
    iris = predict_iris(what),
    alive = alive(),
    add = add_floats(pc[2], pc[3])))
}

Rserve:::run.Rserve(http.port=8092)