Differences

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--- summer_2019:glowscript_tips [2019/08/07 04:46]
wellerd
+++ 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>
@@ Line 39: / Line 84: @@
 AbsoluteNumber = abs(Number)
 </code>
-  * **Exponents** - to write an exponent in Python you have to use a ''$**$'' rather than ''$^$''. For example, to write $A=5.43*10^4$ in code you would write:
+  * **Exponents** - to write an exponent in Python you have to use a $**$ rather than ^. For example, to write $A=5.43*10^4$ in code you would write:
 <code>
 A=5.42*10**4
@@ Line 63: / Line 108: @@
 mag1=mag(vector1) #This will calculate sqrt(1^2+2^2+3^2)
 </code>
-==== Graphing ====
 ==== Tips for Coding ====
@@ Line 82: / Line 124: @@
 R=20 #cm (Everything in this line before the # would run in the program, everything after the # is ignored)
 </code>
+  * **Indentation errors** - these can be tricky sometimes. The best way to fix these is to [BACKSPACE] the faulty code up to the line above it and then pressing [ENTER] again to separate the lines and reset the indentation. This is not the only way to fix indentation errors.
 ==== Math Review ====
 Check out this link for a **[[http://p3server.pa.msu.edu/coursewiki/doku.php?id=184_notes:math_review#Vector_Notation|useful math review]]**.