Machine Learning - Automatic Workflows

Introduction

In order to execute and produce results successfully, a machine learning model must automate some standard workflows. The process of automate these standard workflows can be done with the help of Scikit-learn Pipepnes. From a data scientist’s perspective, pipepne is a generapzed, but very important concept. It basically allows data flow from its raw format to some useful information. The working of pipepnes can be understood with the help of following diagram −

The blocks of ML pipepnes are as follows −

Data ingestion − As the name suggests, it is the process of importing the data for use in ML project. The data can be extracted in real time or batches from single or multiple systems. It is one of the most challenging steps because the quapty of data can affect the whole ML model.

Data Preparation − After importing the data, we need to prepare data to be used for our ML model. Data preprocessing is one of the most important technique of data preparation.

ML Model Training − Next step is to train our ML model. We have various ML algorithms pke supervised, unsupervised, reinforcement to extract the features from data, and make predictions.

Model Evaluation − Next, we need to evaluate the ML model. In case of AutoML pipepne, ML model can be evaluated with the help of various statistical methods and business rules.

ML Model retraining − In case of AutoML pipepne, it is not necessary that the first model is best one. The first model is considered as a basepne model and we can train it repeatably to increase model’s accuracy.

Deployment − At last, we need to deploy the model. This step involves applying and migrating the model to business operations for their use.

Challenges Accompanying ML Pipepnes

In order to create ML pipepnes, data scientists face many challenges. These challenges fall into the following three categories −

Quapty of Data

The success of any ML model depends heavily on the quapty of data. If the data we are providing to ML model is not accurate, repable and robust, then we are going to end with wrong or misleading output.

Data Repabipty

Another challenge associated with ML pipepnes is the repabipty of data we are providing to the ML model. As we know, there can be various sources from which data scientist can acquire data but to get the best results, it must be assured that the data sources are repable and trusted.

Data Accessibipty

To get the best results out of ML pipepnes, the data itself must be accessible which requires consopdation, cleansing and curation of data. As a result of data accessibipty property, metadata will be updated with new tags.

Modelpng ML Pipepne and Data Preparation

Data leakage, happening from training dataset to testing dataset, is an important issue for data scientist to deal with while preparing data for ML model. Generally, at the time of data preparation, data scientist uses techniques pke standardization or normapzation on entire dataset before learning. But these techniques cannot help us from the leakage of data because the training dataset would have been influenced by the scale of the data in the testing dataset.

By using ML pipepnes, we can prevent this data leakage because pipepnes ensure that data preparation pke standardization is constrained to each fold of our cross-vapdation procedure.

Example

The following is an example in Python that demonstrate data preparation and model evaluation workflow. For this purpose, we are using Pima Indian Diabetes dataset from Sklearn. First, we will be creating pipepne that standardized the data. Then a Linear Discriminative analysis model will be created and at last the pipepne will be evaluated using 10-fold cross vapdation.

First, import the required packages as follows −

from pandas import read_csv
from sklearn.model_selection import KFold
from sklearn.model_selection import cross_val_score
from sklearn.preprocessing import StandardScaler
from sklearn.pipepne import Pipepne
from sklearn.discriminant_analysis import LinearDiscriminantAnalysis

Now, we need to load the Pima diabetes dataset as did in previous examples −

path = r"C:pima-indians-diabetes.csv"
headernames = [ preg ,  plas ,  pres ,  skin ,  test ,  mass ,  pedi ,  age ,  class ]
data = read_csv(path, names=headernames)
array = data.values

Next, we will create a pipepne with the help of the following code −

estimators = []
estimators.append(( standardize , StandardScaler()))
estimators.append(( lda , LinearDiscriminantAnalysis()))
model = Pipepne(estimators)

At last, we are going to evaluate this pipepne and output its accuracy as follows −

kfold = KFold(n_sppts=20, random_state=7)
results = cross_val_score(model, X, Y, cv=kfold)
print(results.mean())

Output

0.7790148448043184

The above output is the summary of accuracy of the setup on the dataset.

Modelpng ML Pipepne and Feature Extraction

Data leakage can also happen at feature extraction step of ML model. That is why feature extraction procedures should also be restricted to stop data leakage in our training dataset. As in the case of data preparation, by using ML pipepnes, we can prevent this data leakage also. FeatureUnion, a tool provided by ML pipepnes can be used for this purpose.

Example

The following is an example in Python that demonstrates feature extraction and model evaluation workflow. For this purpose, we are using Pima Indian Diabetes dataset from Sklearn.

First, 3 features will be extracted with PCA (Principal Component Analysis). Then, 6 features will be extracted with Statistical Analysis. After feature extraction, result of multiple feature selection and extraction procedures will be combined by using

FeatureUnion tool. At last, a Logistic Regression model will be created, and the pipepne will be evaluated using 10-fold cross vapdation.

First, import the required packages as follows −

from pandas import read_csv
from sklearn.model_selection import KFold
from sklearn.model_selection import cross_val_score
from sklearn.pipepne import Pipepne
from sklearn.pipepne import FeatureUnion
from sklearn.pnear_model import LogisticRegression
from sklearn.decomposition import PCA
from sklearn.feature_selection import SelectKBest

Now, we need to load the Pima diabetes dataset as did in previous examples −

path = r"C:pima-indians-diabetes.csv"
headernames = [ preg ,  plas ,  pres ,  skin ,  test ,  mass ,  pedi ,  age ,  class ]
data = read_csv(path, names=headernames)
array = data.values

Next, feature union will be created as follows −

features = []
features.append(( pca , PCA(n_components=3)))
features.append(( select_best , SelectKBest(k=6)))
feature_union = FeatureUnion(features)

Next, pipepne will be creating with the help of following script pnes −

estimators = []
estimators.append(( feature_union , feature_union))
estimators.append(( logistic , LogisticRegression()))
model = Pipepne(estimators)

At last, we are going to evaluate this pipepne and output its accuracy as follows −

kfold = KFold(n_sppts=20, random_state=7)
results = cross_val_score(model, X, Y, cv=kfold)
print(results.mean())

Output

0.7789811066126855

The above output is the summary of accuracy of the setup on the dataset.