logistic regression

Stratified sampling

Imbalanced data is one of the major issue in classification problem. Why we will have imbalanced data? Let’s say if i have 100 customer who is holding credit card, may be maximum I may have 2 or 3% defaulters and remaining 95 to 97% are perfect payers (This is called presence of minority class ),Continue reading “Stratified sampling”

Deriving Logistic regression equation

Lets derive logistic regression equation. oops we know if we use linear regression we will get continuous values, but we need binary results. We are still not done to find the final logistic regression function. Step 1: we apply some algebra knowledge here to find equation. If we move log function to another side itContinue reading “Deriving Logistic regression equation”

Logistic regression assumptions

Binary Output Variable: Logistic regression is intended for binary (two-class) classification problems. It will predict the probability of an instance belonging to the default class, which can be snapped into a 0 or 1 classification.Remove Noise: Logistic regression assumes no error in the output variable (y), consider removing outliers and possibly misclassified instances from your Continue reading “Logistic regression assumptions”

Classification Accuracy,Confusion matrix, AUC and ROC

we already discussed how to calculate accuracy for linear regression with the help of R-Square, Adjusted R-Square, MSE etc..Can we use the same mechanism to calculate the accuracy for classification problem? Simple answer is NO, we have different mechanism to calculate accuracy for classification problems. Classification Accuracy: It is very simple to calculate, number ofContinue reading “Classification Accuracy,Confusion matrix, AUC and ROC”

Logistic regression will comes under supervised learning to solve classification problems.some real time use cases like if customer is good or bad,predicting defaulters, Email spam detection, Fraud detection etc.. Great I have a question why can’t we use linear regression to solve classification problem? As we seen above the usage of logistic regression we needContinue reading “Logistic regression”