c_meyer/pxt-calliope
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Add info to some examples (#716)

Browse Source 
* Add info to some examples

* Push a few more descriptions

* Couple more

* Touch up card descriptions

* Fix 'drop' typo

* Live typo
This commit is contained in:
Galen Nickel
2018-03-21 16:30:58 -07:00
committed by GitHub
parent 93163ee226
commit 6398d60b3b
10 changed files with 47 additions and 17 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
docs/examples/pi-montecarlo.md
View File

@ -4,13 +4,13 @@ Approximate the value of **pi** using your @boardname@!
## Thinking about it...
Ok, let's pretend that a circle fits inside a square where the edge of the circle touches the sides of the square. If we say that the radius, called ``r``, of circle is `1` then the length of each side of the square is `2`, or ``2 * r``. The area of the circle is ``(pi * r) ** 2`` and the area of the square then is ``(pi * r * 2) ** 2``. We don't know what ``pi`` is so we can arrange a relationship between the area of the circle and the area of the square to solve for the value of ``pi``.
Ok, let's pretend that a circle fits inside a square where the edge of the circle touches the sides of the square. If we say that the radius, called ``r``, of circle is `1` then the length of each side of the square is `2`, or ``2 * r``. The area of the circle is ``pi * (r ** 2)`` and the area of the square then is ``(r * 2) ** 2``. We don't know what ``pi`` is so we can arrange a relationship between the area of the circle and the area of the square to solve for the value of ``pi``.
### Circle and square
An interesting relationship between the circle and the square is that the area of the circle divided by the area of the square is:
``area ratio = ((pi * r) ** 2) / ((pi * r * 2) ** 2) = pi / 4``
``area ratio = (pi * (r ** 2)) / ((r * 2) ** 2) = pi / 4``
Well, we can see that if we knew the area of both the circle and the square we could find out what the value of ``pi`` is! It's simply this:
@ -41,7 +41,7 @@ Of course, we can't completely fill the area of both shapes with dots but we cou
### Making and counting dots
To make the "dots" we can randomly make a value and see if it would fit as a coordinate with in the shape we're trying to fill. If it fits, increase the count of dots and try to make more for some amount of time. The more dots created, the better the accuracy of our value for ``area ratio``.
To make the "dots" we can randomly make a value and see if it would fit as a coordinate within the shape we're trying to fill. If it fits, increase the count of dots and try to make more for some amount of time. The more dots created, the better the accuracy of our value for ``area ratio``.
### Monte Carlo method