README.md

coding-the-matrix

Coding work for the book from http://codingthematrix.com/.

While this does have some overlap with the Coursera course, the exercises tend to be more involved.

Code written using Python 3.5.4 on OSX using the Anaconda distribution.

Each chapter's work is setup in a corresponding python package chapter/#

So to use you would type something like:

>>> from chapter.0 import dictutil
>>> [dictutil.row(p, 20) for p in range(15)]

• Graded Stencil Files
• Book Python Resources

Comments

• itertools has been useful for many different problems
• Given all the issues with floating point arithmetic, should use the Decimal module instead.
• Sections entitled Problem X.Y.Z are exercises for the reader.
• Problem 2.14.10 the Vec class should be implemented earlier in the chapter.
• Problem 4.17.12 the Mat class should be implemented earlier in the chapter.
• solver.py module implementation is based 64 encoded pyc. No comments explaining why.
• 5.11 The Exchange Lemma is not well explained. It could use a concrete example before Problem 5.14.11
• 9.2.2 Augmenting project_orthogonal goes way off the reservation:
  • The Mathese vs Python array indexing syntax of one versus zero, respectively is annoying. That this section announces the Mathese therein will use zero is simply maddening.
  • Then telling the reader about what's Pythonic or not, is even nuttier.

Kindle Version Bugs

• OSX copy paste is a clown show.
  • Never clear when it's possible to copy or not.
  • Copying includes the copy right text.
• Missing Images
  • p 484
  • p 499-500 Fourier Transformations & Charting Waves

Errors Found

All of the following have also been sent to info@codingthematrix.com

A ^ at the end of a line indicates a "confirmed" response.

• 2.9.15 Off By One^
• 4.9.3 XKCD Matrix Transform should reference https://xkcd.com/184/ not https://xkcd.com/824/ ^
• ecc_lab.py Task 10 Bug: passes doctest but fails via submit.py ^
• matrix_resources/images: Section 4.15.5 references but not on the web site. Checked:
  • http://resources.codingthematrix.com/
  • http://grading.codingthematrix.com/edition1/index.html
  • http://resources.codingthematrix.com/images/
  • http://resources.codingthematrix.com/matrix_resources/images/
• geometry_lab.py Task 4 (Line 59) missing lead doctest angle brackets ">>>"
• The_Matrix_Problems.py Problem 16's most_agreeing_pair_of_countries is marked incorrect
• Problem 5.14.9 (c) not answerable due to value of last vector being cutoff (Kindle edition). Copy and paste doesn't solve as it comes across as:

  [one, one, 0, one, one], [0, 0, one, 0, 0], [0, 0, one, one, one], [one, 0, one, one, one], [one, one, one,
  
  Problem 5.14.10: Each of the subproblems...
  

• submit.py grading for Problem 7.9.7 in Gaussian_Eliminating_problems.py expects row_list but has rowlist.
• submit.py grading for Problem 8.6.3 #2 in The_Inner_Product_problems.py does not adhere to the description of 6 decimal places allowed where project_along(b, v) and project_orthogonal_1(b, v) produce decimals that I in turn rounded. Instead it wants vector values to fractions (x/y).
• http://resources.codingthematrix.com/orthonormalization.py update doctests to match http://grading.codingthematrix.com/edition1/Orthogonalization_problems.py