Week3 Optional lab 02 - sigmoid function, value of z

Hi, in week 3 optional lab 02 - sigmoid function, the part when we draw the classification graph, why z (orange line) here does not match the line in a linear regression model. (please see image for clarification)

I thought we would run the linear regression model as usual, then map the input to a sigmoid function to get the final function. Hence, z should match the linear regression model

Hi @Oanh,

I think the message is, if you had fit the data to a linear regression model, it’s likely you will get the green line (illustrated below) instead of the orange line. The green line is different because it attempts to pass through the data points.

Raymond

Screenshot from 2022-07-21 10-08-01