Differences

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--- summer_2019:glowscript_tips [2019/08/07 05:40]
wellerd [Programmer Logic]
+++ summer_2019:glowscript_tips [2019/08/13 00:27] (current)
wellerd
@@ Line 23: / Line 23: @@
   * **Printing values and text** - The ''print()'' command will output any value called from within the parentheses. You can print variables and attributes from your code as a way of checking what numbers the simulation has calculated. The following code creates a conical object named ''IceCreamCone'', and the ''print(IceCreamCone.size.x)'' command prints the x-component of the object's size attribute. If you want to print text, it must be transformed into a "string" of letters by using quotation marks within the ''print()'' command.
 <code>
-IceCreamCone=cone(pos=vec(10,20,0), axis=vec(5,0,0), size=vec(12,3,3)
+IceCreamCone=cone(pos=vec(0,0,0), axis=vec(0,-5,0), size=vec(3,1,1))
-print(IceCreamCone.size.x)
+print("Ice cream cone length:", IceCreamCone.size.x)
 print("Two scoops of butter pecan please!")
 </code>
 ==== Graphing ====
+  * **Graphs** - the most convenient graphs in Glowscript utilize the ''gcurve'' command which plots x-y data points as a scatterplot and connects the points with a line. In general, Three lines of code are needed to graph in Glowscript...
+  - A line above the while loop which creates the axes and titles of the graph (line 3 in the picture below).
+  - A line above the while loop which tells the program what you are about to graph (line 4 in the picture below).
+  - A line inside of the while loop which plots the respective x-y data point for that iteration of the while loop (line 19 in the picture below).
+{{:summer_2019:python-trinket-physics.png?400|}}
+  * **Another graphing example** - In the following code, ''MyGraph1'' is needed to set up the graphing window with its various axes titles, minimum and maximum boundaries, and other features. The line with ''HeightGraph'' names a particular data-set that will be represented on our scatterplot. Lastly, **within the while loop**, the ''HeightGraph.plot(t,Cart.pos.y)'' command is used to ''plot'' data points for our specified data-set (''t'' will be on the x-axis and ''Cart.pos.y'' will be on the y-axis).
+<code>
+MyGraph1 = graph(title='Height vs Time', xtitle='Time (s)', ytitle='Height (m)', fast=False) #Name our graph and set some features
+HeightGraph = gcurve(color=color.red, label='Height') # Specifies a name for the data-set that we will be plotting
+Cart=box(pos=vec(0,0,0), size=vec(1,1,1),color=color.magenta)
+t=0
+dt=1
+while True:
+    rate(100)
+    Cart.pos=Cart.pos+vec(0,1,0)*dt
+    # This line plots data points as the program iterates
+    HeightGraph.plot(t,Cart.pos.y) # t will be on the x-axis and Cart.pos.y will be on the y-axis
+    t=t+dt
+</code>
+==== Programmer Logic ====
+* **If-then statements** - these act as triggers to start some new event once a condition in met. For example, it we have an object moving to the right with ''particle.velocity=vec(1,0,0)'' and we want it to move in the opposite direction after 10 seconds, then you might use the following code.
+<code>
+Particle = sphere(pos=vec(0,0,0))
+Particle.velocity=vec(1,0,0)
+t=0
+dt=1
+tf=20
+while t >= tf:
+  rate(100)
+  Particle.pos=Particle.pos+Particle.velocity*dt
+  if t >= 10:
+    Particle.velocity=vec(-1,0,0)
+  t=t+dt
+</code>
 ==== Mathematics ====