REGRESSION EXAMPLES
DATA CLEANING PYTHON
DATA MUNGING
MACHINE LEARNING RECIPES
PANDAS CHEATSHEET
ALL TAGS
# How to create and optimize a baseline linear regression model?

# How to create and optimize a baseline linear regression model?

This recipe helps you create and optimize a baseline linear regression model

Many a times while working on a dataset and using a Machine Learning model we don't know which set of hyperparameters will give us the best result. Passing all sets of hyperparameters manually through the model and checking the result might be a hectic work and may not be possible to do.

To get the best set of hyperparameters we can use Grid Search. Grid Search passes all combinations of hyperparameters one by one into the model and check the result. Finally it gives us the set of hyperparemeters which gives the best result after passing in the model.

So this recipe is a short example of how we can create and optimize a baseline linear regression model

```
from sklearn import decomposition, datasets
from sklearn import linear_model
from sklearn.pipeline import Pipeline
from sklearn.model_selection import GridSearchCV, cross_val_score
from sklearn.preprocessing import StandardScaler
```

Here we have imported various modules like decomposition, datasets, linear_model, Pipeline, StandardScaler and GridSearchCV from differnt libraries. We will understand the use of these later while using it in the in the code snipet.

For now just have a look on these imports.

Here we have used datasets to load the inbuilt boston dataset and we have created objects X and y to store the data and the target value respectively.
```
dataset = datasets.load_boston()
X = dataset.data
y = dataset.target
```

StandardScaler is used to remove the outliners and scale the data by making the mean of the data 0 and standard deviation as 1. So we are creating an object std_scl to use standardScaler.
```
std_slc = StandardScaler()
```

We are also using Principal Component Analysis(PCA) which will reduce the dimension of features by creating new features which have most of the varience of the original data.
```
pca = decomposition.PCA()
```

Here, we are using Linear Regression as a Machine Learning model to use GridSearchCV. So we have created an object linear.
```
linear = linear_model.LinearRegression()
```

Pipeline will helps us by passing modules one by one through GridSearchCV for which we want to get the best parameters. So we are making an object pipe to create a pipeline for all the three objects std_scl, pca and linear.
```
pipe = Pipeline(steps=[('std_scl', std_scl),
('pca', pca),
('linear', linear)])
```

Now we have to define the parameters that we want to optimise for these three objects.

StandardScaler doesnot requires any parameters to be optimised by GridSearchCV.

Principal Component Analysis requires a parameter 'n_components' to be optimised. 'n_components' signifies the number of components to keep after reducing the dimension.
```
n_components = list(range(1,X.shape[1]+1,1))
```

Linear Regression requires a parameter 'normalize' to be optimised by GridSearchCV.
```
normalize = [True, False]
```

Now we are creating a dictionary to set all the parameters options for different modules.
```
parameters = dict(pca__n_components=n_components,
linear__normalize=normalize)
```

Before using GridSearchCV, lets have a look on the important parameters.

- estimator: In this we have to pass the models or functions on which we want to use GridSearchCV
- param_grid: Dictionary or list of parameters of models or function in which GridSearchCV have to select the best.
- Scoring: It is used as a evaluating metric for the model performance to decide the best hyperparameters, if not especified then it uses estimator score.

```
clf = GridSearchCV(pipe, parameters)
clf.fit(X, y)
```

Now we are using print statements to print the results. It will give the values of hyperparameters as a result.
```
print('Best Number Of Components:', clf.best_estimator_.get_params()['pca__n_components'])
print(); print(clf.best_estimator_.get_params()['linear'])
```

As an output we get:
Best Number Of Components: 4 LinearRegression(copy_X=True, fit_intercept=True, n_jobs=None, normalize=True)

In this data science project, you will contextualize customer data and predict the likelihood a customer will stay at 100 different hotel groups.

In this supervised learning machine learning project, you will predict the availability of a driver in a specific area by using multi step time series analysis.

Data Science Project in R-Predict the sales for each department using historical markdown data from the Walmart dataset containing data of 45 Walmart stores.

In this data science project, you will work with German credit dataset using classification techniques like Decision Tree, Neural Networks etc to classify loan applications using R.

In this R data science project, we will explore wine dataset to assess red wine quality. The objective of this data science project is to explore which chemical properties will influence the quality of red wines.

This data science in python project predicts if a loan should be given to an applicant or not. We predict if the customer is eligible for loan based on several factors like credit score and past history.

In this Kmeans clustering machine learning project, you will perform topic modelling in order to group customer reviews based on recurring patterns.

In this data science project, we will predict the credit card fraud in the transactional dataset using some of the predictive models.

Use the Adult Income dataset to predict whether income exceeds 50K yr based on
census data.

PySpark Project-Get a handle on using Python with Spark through this hands-on data processing spark python tutorial.