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Is Big O(logn) log base e?
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But it's very easy to show that log_2 n is in Θ(log_a n) for any base a, so I'm not sure I see how using base 2 is "more correct".
– bcat
Oct 15 '09 at 0:34
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Standardize data columns in R
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z = runif(10, 10, 20))
dat
dat2 <- dat %>% mutate_at(c("y", "z"), ~(scale(.) %>% as.vector))
dat2
which gives me this:
> dat
x y z
1 29.75859 3.633225 14.56091
2 30.05549 3.605387 12.65187
3 30.21689 3.318092 13.04672
4 29.53086 3.079992...
How to do parallel programming in Python?
... pool:
from multiprocessing import Pool
pool = Pool()
result1 = pool.apply_async(solve1, [A]) # evaluate "solve1(A)" asynchronously
result2 = pool.apply_async(solve2, [B]) # evaluate "solve2(B)" asynchronously
answer1 = result1.get(timeout=10)
answer2 = result2.get(timeout=10)
This will spa...
What kind of leaks does automatic reference counting in Objective-C not prevent or minimize?
...chain referring back to an earlier object.
It is for this reason that the __unsafe_unretained and __weak ownership qualifiers exist. The former will not retain any object it points to, but leaves open the possibility of that object going away and it pointing to bad memory, whereas the latter doesn...
How do I keep Python print from adding newlines or spaces? [duplicate]
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You can from __future__ import print_function in Python 2.6
– jfs
Nov 2 '08 at 18:10
14
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How to check Django version
... is as an executable command:
$ python -c "import django; print(django.get_version())"
2.0
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Python requests - print entire http request (raw)?
...'X-Custom':'Test'},data='a=1&b=2')
prepared = req.prepare()
def pretty_print_POST(req):
"""
At this point it is completely built and ready
to be fired; it is "prepared".
However pay attention at the formatting used in
this function because it is programmed to be pretty
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Why does the MongoDB Java driver use a random number generator in a conditional?
... laws it is a trivial observation that this piece of code amounts to
if (!_ok && Math.random() <= 0.1)
return res;
The commit that originally introduced this logic had
if (_ok == true) {
_logger.log( Level.WARNING , "Server seen down: " + _addr, e );
} else if (Math.random() < 0...
Creating your own header file in C
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foo.h
#ifndef FOO_H_ /* Include guard */
#define FOO_H_
int foo(int x); /* An example function declaration */
#endif // FOO_H_
foo.c
#include "foo.h" /* Include the header (not strictly necessary here) */
int foo(int x) /* Functi...
How to get a time zone from a location using latitude and longitude coordinates?
...rces of time zone boundary data, but are no longer actively maintained.
tz_world - the original shapefile data from Eric Muller
whereonearth-timezone - GeoJSON version with WOEDB data merged in
Time Zone Geolocation Offline Implementations
Implementations that use the Timezone Boundary Builder dat...