smallscale changes to javascript tree traversal, jarvis julia, and euler text. (#492)

Author: leios

contents/forward_euler_method/forward_euler_method.md

@@ -95,7 +95,8 @@ That said, variations of this method *are* certainly used (for example Crank-Nic
 
 Like in the case of [Verlet Integration](../verlet_integration/verlet_integration.md), the easiest way to test to see if this method works is to test it against a simple test-case.
 Here, the most obvious test-case would be dropping a ball from 5 meters, which is my favorite example, but proved itself to be slightly less enlightening than I would have thought.
-So, this time, let's remove ourselves from any physics and instead solve the following ODE: $$y' = 5y$$. Note that in this case, the velocity is directly given by the ODE and the acceleration is not part of the model.
+So, this time, let's remove ourselves from any physics and instead solve the following ODE: $$y(t)' = -3t$$ with the initial condition that $$y(0) = 1$$.
+Note that in this case, the velocity is directly given by the ODE and the acceleration is not part of the model.
 
 {% method %}
 {% sample lang="jl" %}

contents/jarvis_march/code/julia/jarvis.jl

@@ -22,8 +22,7 @@ function jarvis_march(points::Vector{Pos})
 
     # Find cross product between points
     curr_product = jarvis_cross(Pos(0,0), hull[1], curr_point)
-    #while (curr_point != hull[1])
-    while (length(hull) < 4)
+    while (curr_point != hull[1])
         for point in points
                 product = 0.0
             if (i == 1)

contents/tree_traversal/tree_traversal.md

@@ -14,8 +14,8 @@ Trees are naturally recursive data structures, and because of this, we cannot ac
 {% sample lang="java" %}
 [import:110-126, lang:"java"](code/java/Tree.java)
 {% sample lang="js" %}
-This has not been implemented in your chosen language, so here is the Julia code
-[import:3-7, lang:"julia"](code/julia/Tree.jl)
+[import:1-10, lang:"javascript"](code/javascript/tree.js)
+As a note, a `node` struct is not necessary in javascript, so this is an example of how a tree might be constructed.
 {% sample lang="py" %}
 [import:1-4, lang:"python"](code/python/Tree_example.py)
 {% sample lang="scratch" %}