Techniques to Estimate Model Parameters
Learn about different techniques to estimate model parameters using probability.
Maximum likelihood estimation (MLE), maximum a posteriori estimation (MAP), and Bayesian inference are all techniques used in machine learning to estimate the parameters of model-given data.
Maximum likelihood estimation
Maximum likelihood estimation (MLE) is a method for estimating the parameters of a probability distribution given a dataset. It involves finding the set of parameters that maximizes the likelihood of the observed data. MLE is a simple and widely used method in machine learning, particularly in supervised learning. It is generally easier to compute and understand. However, it doesn’t take into account any prior knowledge or belief about the parameters.
Example: Bug prediction
One example of using MLE in software engineering is in the field of bug prediction. Bug prediction is a technique used to predict the likelihood of a code having a bug. In this case, the goal is to estimate the probability of a bug given certain code features, such as the number of lines of code, the number of comments, and the number of changes.
Here’s how this can be done in Python:
from sklearn.linear_model import LogisticRegressionimport pandas as pd# Create a training datasetcode_data = pd.read_csv("software_data_file.csv")# Extract the featuresX = code_data[["lines_of_code", "comments", "changes"]]# Create the labelsy = code_data["bug"]# Create and train the modelmodel = LogisticRegression(solver='lbfgs')model.fit(X, y)# Test the model with new code datanew_code = [[100, 20, 5]] #Change these values and see effect on the probabilityprediction = model.predict_proba(new_code)prob_a=prediction[0][1]*100print(f"The likelihood of having a bug in new code is {round(prob_a,2)}%")
In this code, a ...