enter image description here This is from the Coursera Supervised Machine Learning: Regression and Classificationby Andrew Ng, week 3 practice lab. X₁¹ X₂¹ X₁² X₁¹X₂¹ X₂² X₁³ X₁²X₂¹ X₁¹X₂² X₂³ X₁⁴ X₁³X₂¹ X₁²X₂² X₁¹X₂³ X₂⁴ X₁⁵ X₁⁴X₂¹ X₁³X₂² X₁²X₂³ X₁¹X₂⁴ X₂⁵ X₁⁶ X₁⁵X₂¹ X₁⁴X₂² X₁³X₂³ X₁²X₂⁴ X₁¹X₂⁵ X₂⁶
Below is how the 27 dimensional vectory is made. I wanted to figure out how it was made but couldn't find anything online so I figured it by hand and calculator.
