Hoi Wong
  • Effective C++ Consolidated

    Effective C++ is organized in terms of commandments (jokingly), but the ideas can also be organized by the rationales so the 50 recommendations can be easily compressed into <250 lines of text by starting from the main reasoning of C++'s design (extending C). This is a work-in-progress and might sacrifice some accuracy for menomics (like classifiying templates under preprocessors, which is not technically true)

  • Frequency Domain Interpretation of Constant Overlap Add (COLA)

    In EE367B / Music 421 taught at Stanford University, the derivation between COLA(R) <-> Nyquist(2*Pi/R) is a long page of messy derivation using IDTFT (i.e. there's no intuiton in frequency domain).

    Given my experience with signal processing, pretty much everything LTI has an accessible frequency domain interpretation and I believe this transform pair is no exception. I worked it out in frequency domain using a few routine signal processing tricks (factoring dirac shifters out, superposition, impulse train <-> impulse train transform pair, sifting) and turned it into a easy derivation and interpretation.

  • Super condensed review sheet for basic Real Analysis (aka Baby Rudin)

  • High school electricity (physics) and mathematics done the easy way.

    This article is a bit outdated since the curriculum in Hongkong has changed and HKCEE/HKALE no longer exist. I also see some good changes in the new HKDSE that they finally teach students to invert matrices through Gaussian elimination in place of of Cramer's rule.

    I still think they should teach Euler's formula early on because without that, AC circuit analysis becomes a mess like this (Phasors) when it could have been easily done with basic complex number manipulations and reading the magnitude and phase off it.

  • My Quora answer to "What makes DSP so difficult?"