Monday January 22nd

Plotting in Julia

Spent today plotting in Julia

  • Wrote a function and plotted X against Y

  • Then plotted it. The grid on command apparently changed from grid("on") to gr(). Oh..kayyy.
  • Also, what’s neat is that for the title, it truncates after any (, but it will, if you type ^, raise that to the power, as you would like it to do, which is nice!

User Defined Types in Julia

  • User defined types in Julia are just awesome. You can add constraints, and there are Any types, which are the subset of all types, and other types, such as Abstract, Concrete, and Composite.
  • Any is the supertype of all types
  • Concrete types can hold values, such as Int64 or Float64.
  • Abstract types cannot hold values
  • You can see the subtypes of a type by typing subtypes(T), where T is the specific type.
  • You can ask Float64 <: Any which reads “Is Float a subtype of Any?”, which is true because Any is a supertype that contains all subtypes.
  • I’m really enjoying it.


  • You can check types by ===(x, y) or is(x, y). This does bit-level comparison.

Other people

  • plotted some interesting stuff like the Legendre Polynomial or the Lemniscate function. I didn’t know about Lemniscate before, so that was really interesting! I think I may have made a moving sculpture via welding before that uses some version of the concept, though (don’t ask).


  • I have a list of things to get together for my sailing trip next week
  • I’m going to Sparklecon this weekend!
  • I’m reviewing types tonight and trying to get started on Week 3’s homework since I have a short week next week (ie on a boat)!
  • I’m going to work through the final SQL section of my Udacity course, and finish up Project 1.
  • I’m going to get that Julia certificate!
  • I saw this bokeh function, but it looks like it may be discontinued? In particular, this issue.


  • Oh, I watched this video on Julia’s Type system. It’s by Jeff Bezanson and it’s called “The State of the Type System”
  • Need to learn more about
    • Intersection Types (“given two types, find a type that is a subtype of both”)
    • Union Types

And that’s about it!

Written on January 22, 2018