Showing posts with label history. Show all posts
Showing posts with label history. Show all posts

Wednesday, October 5, 2016

Something For Your Mind, Polymath Podcast episode 2

A is for Anomaly

In this episode, "A is for Anomaly", our first of the alphabetical episodes, we cover financial fraud, the Roman quaestores, outliers, PDFs and EKGs. Bleep... Bleep... Bleep...
"so perhaps this is not the ideal way of keeping track of 15 individuals..."

Something for your mind is available on



art·chiv.es

/'ärt,kīv/



Francois Dion
@f_dion
P.S. There is a bit more detail on this podcast as a whole, on linkedin.
Posted by at No comments:
Labels: , , , , , , , ,

Monday, April 18, 2016

Los Alamos 10742: The Making of

Modern rendering of the original 1947 Memo 10742

Before reading


If you've not read the first part (The return of the Los Alamos Memo 10742) of this blog, go there now. There will be a link to come back here at the end, so you don't forget ...

Your assignment


If you remember, in the previous article, I had asked the students (and, you, the reader) to try this exercise:

"Replicate either:
a) the whole memo
or
b) the list of numbers 
Whichever assignment you choose, the numbers must be generated programmatically."

One possible way

We'll use Python 3 and do b):

In [1]:
def num_to_words(n):
    """Returns a number in words, covering 0 to 100 inclusive."""
    n2w = {
        0: 'zero', 1: 'one', 2: 'two', 3: 'three', 4: 'four', 5: 'five', 6: 'six',
        7: 'seven', 8: 'eight', 9: 'nine', 10: 'ten', 11: 'eleven', 12: 'a dozen',
        13: 'thirteen', 14: 'fourteen', 15: 'fifteen', 16: 'sixteen', 17: 'seventeen',
        18: 'eighteen', 19: 'nineteen', 
        20: 'twenty', 30: 'thirty', 40: 'fourty', 50: 'fifty', 60: 'sixty', 70: 'seventy',
        80: 'eighty', 90: 'ninety', 100: 'one hundred'
    }
    try:
        return n2w[n]
    except KeyError:
        return n2w[n-n%10] + ' ' + n2w[n%10]
The famous twelve as 'a dozen'
In [2]:
num_to_words(12)
Out[2]:
'a dozen'
In [3]:
num_to_words(7)
Out[3]:
'seven'
In [4]:
num_to_words(67)
Out[4]:
'sixty seven'
In [5]:
num_to_words(100)
Out[5]:
'one hundred'
Generating the alphabetical word list, not including number 10
In [6]:
word_tuples = sorted([(num_to_words(num),num) for num in range(101) if num != 10])
Now that the list is sorted alphabetically, just want the second item of each tuple [1]
In [7]:
result = list(zip(*word_tuples))[1]
Let's print this.
In [8]:
print(str(result)[1:-1])

12, 8, 18, 80, 88, 85, 84, 89, 81, 87, 86, 83, 82, 11, 15, 50, 58, 55, 54, 59, 51, 57, 56, 53, 52, 5, 4, 14, 40, 48, 45, 44, 49, 41, 47, 46, 43, 42, 9, 19, 90, 98, 95, 94, 99, 91, 97, 96, 93, 92, 1, 100, 7, 17, 70, 78, 75, 74, 79, 71, 77, 76, 73, 72, 6, 16, 60, 68, 65, 64, 69, 61, 67, 66, 63, 62, 13, 30, 38, 35, 34, 39, 31, 37, 36, 33, 32, 3, 20, 28, 25, 24, 29, 21, 27, 26, 23, 22, 2, 0
In [ ]:

If you read the commentaries for the previous article on the subject, you surely ran into Edward Carney's almost working proposed solution. I am adding it here as another way of attacking the problem. Edward used a module named num2words. As you'll discover over years of writing python code, most anything you can think of has already been done. And in some cases, multiple times.

Why did I say almost working? Let's see if somebody finds the issue. If not I'll post the correction in a future post (the very next one will diverge from this subject to talk about fractals). I'll also introduce the inflect module and since we're introducing some NLP concepts, I'll bring in NLTK too.

In [1]:
import num2words as n2w
In [2]:
key_set = []
[key_set.append(n2w.num2words(i)) for i in list(range(101))]
key_set[12] = 'dozen'
key_set[100] = 'one hundred'
numset_dict = dict(zip(key_set,list(range(101))))
line_breaks = [14, 30, 46, 62, 78, 94]
for i, k in enumerate(yvals):
    print('{} '.format(k[1]),end='')
    if i in line_breaks:
        print('\n')
---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)
<ipython-input-2-6c7998a49267> in <module>()
      5 numset_dict = dict(zip(key_set,list(range(101))))
      6 line_breaks = [14, 30, 46, 62, 78, 94]
----> 7 for i, k in enumerate(yvals):
      8     print('{} '.format(k[1]),end='')
      9     if i in line_breaks:

NameError: name 'yvals' is not defined






You know the solution? Post it in the comments section.


Francois Dion
@f_dion



















Posted by



at





No comments:
              

















Labels:
,
,
,
,
















          

        

          

        

Saturday, March 5, 2016


          

        










The return of the Los Alamos Memo 10742 -















Modern rendering of the original 1947 Memo 10742









The mathematician prankster



Can you imagine yourself receiving this memo in your inbox in Washington in 1947? There's a certain artistic je ne sais quoi in this memo...



This prank was made by J Carson Mark and Stan Ulam.  A&S was Administration and Services.



And Ulam, well known for working on the Manhattan project, also worked on really interesting things in mathematics. Specifically, a collaboration with Nicholas Constantine Metropolis and John Von Neumann. You might know this as the Monte Carlo method (so named due to Ulam's uncle always asking for money to go and gamble in a Monte Carlo casino...). Some people have learned about a specific Monte Carlo simulation (the first) known as Buffon's needle.





Copying the prankster

When I stumbled upon this many years ago, I decided that it would make a fantastic programming challenge for a workshop and/or class. I first tried it in a Java class, but people didn't get quite into it. Many years later I redid it as part of a weekly Python class I was teaching at a previous employer.



The document is the output of a Python script. In order to make the memo look like it came from the era, I photocopied it. It still didn't look quite right, so I then scanned that into Gimp, bumped the Red and Blue in the color balance tool to give it that stencil / mimeograph / ditto look.




Your assignment



Here is what I asked the students:





"Replicate either:

a) the whole memo

or

b) the list of numbers 



Whichever assignment you choose, the numbers must be generated programmatically."



That was basically it. So, go ahead and try it. In Python. Or in R, or whatever you fancy and post a solution as a comment.



We will come back in some days (so everybody gets a chance to try it) and present some possible methods of doing this. Oh, and why the title of "the return of the Los Alamos Memo"? Well, I noticed I had blogged about it before some years back, but never detailed it...





Learning more on Stan Ulam



See the wikipedia entry and also:





LOS ALAMOS SCIENCE NO. 15, 1987





[EDIT: Part 2 is at: los-alamos-10742-making-of.html]



Francois Dion

@f_dion








Posted by



at





6 comments:
              

















Labels:
,
,
,
,
,
,
,
,
















        

      









Subscribe to:
Posts (Atom)