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HW#7

HW#7

Original Solution:

 

Part 1:

We sample the original solution from last week's homework at the given 12 locations:

  • along Y=0.20: X=-0.6, -0.3, 0.0, 0.3, 0.6
  • along Y=0.40: X=-0.3, 0.0, 0.3, 0.6
  • along Y=0.60: X= 0.0, 0.3, 0.6

The sampled elements are found by using the built-in MATLAB function inpolygon.  We build the sampling matrix S by looping through these elements and treating each iteration as a point source.

We then have d = [S]*u.

 

Part 2:

We use the Representer approach, which uses Lagrange multipliers.  This method was chosen because the number of data is much less than the number of unknowns n.

The following procedure was followed:

 

And the result:

 

Part 3:

rms_bias = 0.0726

rms_misfit = 0.0396

rms_dir = 0.0026

Part 4:

We find the inverse noise by taking the sqrt of the diagonal of Cov(u), where

Cov(u) = [U] * inv(I+R) * cov(d) * inv(I+R)' * [U]'

 

HW7 code: