Talk:Van der Corput sequence: Difference between revisions

From Rosetta Code
Content added Content deleted
m (added a (forced) TOC.)
m (→‎displaying of terms: added whitespace.)
 
(One intermediate revision by the same user not shown)
Line 10: Line 10:
== displaying of terms ==
== displaying of terms ==


In every reference I've looked at, the 2nd term of the van der Corput sequenct (for base two) is
In every reference I've looked at, the 2nd term of the van der Corput sequence (for base two) is
'''.1'''
<br> .1
<br>(not) .10000000
(not) '''.10000000'''
<br><br>I suggest that trailing zeroes illegitimatizes the terms.
<br><br>I suggest that trailing zeroes illegitimize the terms. Mathematically, of course, .1 is equal to .100 (except to an engineer, where trailing zeroes signify more precision). -- [[User:Gerard Schildberger|Gerard Schildberger]] 03:28, 26 March 2012 (UTC)

Mathematically, of course, &nbsp; '''.1''' &nbsp; is equal to &nbsp; '''.100''' &nbsp; (except to an engineer, where trailing zeroes signify more precision). &nbsp; &nbsp; -- [[User:Gerard Schildberger|Gerard Schildberger]] 03:28, 26 March 2012 (UTC)


==Generation of the image in the task description==
==Generation of the image in the task description==

Latest revision as of 21:30, 4 October 2020


Python output

Looks to me like the base 2 sample output for the Python example is actually base 3?--Tikkanz 08:34, 11 March 2011 (UTC)

Umm, my (very good) maths teachers defence in such situations was to say "Excellent lad, you've found the deliberate mistake"! :-)
I'm at work at the moment but will correct the copy/paste error this evening. Thanks, --Paddy3118 09:53, 11 March 2011 (UTC)
Hmm? The text says base 3, numbers do look like base 2. Edit conflict? --Ledrug 07:03, 10 June 2011 (UTC)

displaying of terms

In every reference I've looked at, the 2nd term of the van der Corput sequence (for base two) is

            .1
   (not)    .10000000



I suggest that trailing zeroes illegitimatizes the terms.

Mathematically, of course,   .1   is equal to   .100   (except to an engineer, where trailing zeroes signify more precision).     -- Gerard Schildberger 03:28, 26 March 2012 (UTC)

Generation of the image in the task description

My windows machine has packed up so I am using Ipython on Ubuntu. I did the following to create the image:

<lang python>In [211]: from __future__ import division

In [212]: def vdc(n, base=2):

    ...:     vdc, denom = 0,1
    ...:     while n:
    ...:         denom *= base
    ...:         n, remainder = divmod(n, base)
    ...:         vdc += remainder / denom
    ...:     return vdc

In [213]: plt.plot([(random.random()*0.5, 0.5+vdc(i)*0.5) for i in range(2500)], '.') Out[213]: [<matplotlib.lines.Line2D at 0x12c73f2c>,

<matplotlib.lines.Line2D at 0x1311fe4c>]

In [214]: plt.title('Distribution: Van der Corput (top) vs pseudorandom') Out[214]: <matplotlib.text.Text at 0x12ed6fcc>

In [215]: </lang> --Paddy3118 21:59, 7 August 2012 (UTC)