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Old 06-04-2015, 03:23 PM
sayan751 sayan751 is offline
Junior Member
 
Join Date: Jun 2015
Posts: 5
Default Re: Bias-Variance Analysis

Hi,

I have a doubt regarding g bar.

I tried to calculate the bias for the second learner, i.e. h(x) = ax + b. So this is how did it:
  • Generated around 1000 data points (x ranging from -1 to 1)
  • Then picked up two sample data points at random
  • Solved for a and b using matrix
  • Repeated this process for around 3000 times and
  • Lastly took mean for a and mean for b, which formed the g2 bar
  • Used this g2 bar for calculating the respective bias, which also matched with the given value of bias

Now I have two questions:
1. Please let me know whether I am proceeding in the right direction or not.
2. When I am trying to repeat this process with a polynomial model instead of linear model, my calculated bias for the polynomial model varies in great margin, even if the sample data points doesn't change. For polynomial as well, I took the mean of the coefficients, but still my answer (both g bar and bias) varies greatly with each run. What I am missing here?
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