How to load a R model?
This recipe helps you load a R model
Recipe Objective
Once we have trained a model and tested it's performance to be satisfactory, we should save the model. The trained model is lost as soon as we close the session. Additionally, with large dataset, training a model is quite time-consuming since you have to run the algorithm again and again. Hence, it is ideal to train and save the model which can be loaded later to predict the outcome on the new dataset.
In this recipe, we will demonstrate how to load an existing Regression Tree model and predict the test values
Learn About the Application of ARCH and GARCH models in Real-World
STEP 1: Loading the model
There are two ways to save and load the model:
- using save(), load(): When we use save(), we will have to load it using the same name.
- using saveRDS(), loadRDS(): saveRDS() does not save the model name and we have the flexibilty to load the model in any other name. Bur saveRDS() can only save one object at a time as it is lower-level function.
Most people prefer saveRDS() over save() as it is serialise the object.
Syntax: readRDS(file =)
where: file = path with the file extension .rda
#loading the model
model_regression_Tree = readRDS("C:/Users/Divit/Desktop/Internship/R-recipes_Jan/R_160 onwards/Decision Tree_classifier/model.rda")
#checking whether the model has been loaded with different name
ls()
STEP 2: Load the test dataset
# For data manipulation
library(tidyverse)
# Install readxl R package for reading excel sheets
install.packages("readxl")
library("readxl")
#reading the dataset
test = read_excel('R_254_df_test_regression.xlsx')
# scaling the dataset as the model was built on scaled data
test_scaled = scale(test[2:6])
# using cbind() function to add a new column Outcome to the scaled independent values
test_scaled = data.frame(cbind(test_scaled, Outcome = test$Cost))
glimpse(test_scaled)
Rows: 32 Columns: 6 $ Weight 0.72483012, 0.07204194, 0.17201851, 0.23082825, 0.35432872,... $ Weight1 0.72445274, 0.08459639, 0.17756697, 0.23225555, 0.35803927,... $ Length 0.69959684, 0.09077507, 0.24556027, 0.29715533, 0.34875040,... $ Height 2.15715925, 0.03471101, 0.07758442, 0.14769072, 0.25564092,... $ Width 1.87080937, -0.06904068, 0.29059599, 0.39466263, 0.22707121... $ Outcome 1000.0, 200.0, 300.0, 300.0, 300.0, 430.0, 345.0, 456.0, 51...
STEP 3: Predict cost from test dataset
We use Predict() function to do the same.
Syntax: predict(fitted_model, df, type = '')
where:
- fitted_model = model fitted by train dataset
- df = test dataset
predict_test = predict(model_regression_Tree, test_scaled)
predict_test %>% head()
1 700.909090909091 2 316.625 3 316.625 4 316.625 5 495.9 6 495.9
What Users are saying..
Abhinav Agarwal
I come from Northwestern University, which is ranked 9th in the US. Although the high-quality academics at school taught me all the basics I needed, obtaining practical experience was a challenge.... Read More