Couple of things after skimming through it:
* "Consider a naive implementation of a .* operator to add two sequences
together:" -> to multiply two sequences
* in the equation for polynomial kernel use `\text{Offset}`
* personally would not define `var ret` and use `return ret`. Instead use the
implicit `result` variable and avoid explicit `return`
* semicolons at line ends look weird to me
* in `gaussian` I would define the `var tmp` before the loop and just reassign
* why define `n = x.len` if only used to indicate running index of the loops?
* you didn't show the implementation of `$` for the matrix type. Not a
problem, but I would mention that it has to be defined manually (maybe I missed
a reference to that)
* given that this is numeric code, which should probably run fast, I wouldn't
refer to `nim c -r <file>` without mentioning `-d:danger` to readers
* regarding no SIMD support from the compiler: thanks to macros one can sugar
coat SIMD in principle very well oneself
Other than that, nice article! Always great to see articles talking about Nim
for mathematical / scientific etc. usages!
