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What is the fastest way to check if a class has a function defined?
I'm writing an AI state space search algorithm, and I have a generic class which can be used to quickly implement a search algorithm. A subclass would define the necessary operations, and the algorithm does the rest.
...
Are there any downsides to passing structs by value in C, rather than passing a pointer?
...t;
void give_two_doubles(double * x, double * y)
{
*x = 1.0;
*y = 2.0;
}
point give_point()
{
point a = {1.0, 2.0};
return a;
}
int main()
{
return 0;
}
Compile it with full optimizations
gcc -Wall -O3 foo.c -o foo
Look at the assembly:
objdump -d foo | vim -
This is w...
Python - abs vs fabs
...type of its argument.
In [7]: type(abs(-2))
Out[7]: int
In [8]: type(abs(-2.0))
Out[8]: float
In [9]: type(abs(3+4j))
Out[9]: float
In [10]: type(math.fabs(-2))
Out[10]: float
In [11]: type(math.fabs(-2.0))
Out[11]: float
In [12]: type(math.fabs(3+4j))
------------------------------------------...
Rename an environment with virtualenvwrapper
...
if you do:
$ ack-grep -ai doors ~/.virtualenvs/django/bin
you'll notice that will have doors as location and not django, you'll to change each file with the new location.
solution:
after renamed the folder execute the command below.
$ sed -i "...
Difference between and text
... @BalusC: True, but it's purpose, at the time of writing the HTML 2.0 standard, when there was no CSS, was, as described, to use an image as a button or as a server-side image map. But indeed, you can (ab)use a normal button with a background image to do the same with CSS and HTML.
...
How to convert a unix timestamp (seconds since epoch) to Ruby DateTime?
...n):047:2> end
irb(main):048:1> end
=> #<Benchmark ... @real=2.0e-05 ... @total=0.0>
irb(main):050:0* Benchmark.measure do
irb(main):051:1* ["1318996912", "1318496912"].each do |s|
irb(main):052:2* Time.at(s.to_i).to_datetime
irb(main):053:2> end
irb(main):054:1> end
...
get list from pandas dataframe column
...ntype:{type(col_one_arr)}")
Output:
DataFrame:
one two
a 1.0 1
b 2.0 2
c 3.0 3
d NaN 4
column types:
one float64
two int64
dtype: object
col_one_list:
[1.0, 2.0, 3.0, nan]
type:<class 'list'>
col_one_arr:
[ 1. 2. 3. nan]
type:<class 'numpy.ndarray'>
...
.NET data structures: ArrayList, List, HashTable, Dictionary, SortedList, SortedDictionary — Speed,
...t of the collections are duplicates because generics were added in version 2.0 of the framework.
So, although the generic collections likely add features, for the most part:
List is a generic implementation of ArrayList.
Dictionary is a generic implementation of Hashtable
Arrays are a fixed s...
Difference between '..' (double-dot) and '…' (triple-dot) in range generation?
...s.
>> (-1..2).step(0.5).to_a
=> [-1.0, -0.5, 0.0, 0.5, 1.0, 1.5, 2.0]
>> (-1...3).step(0.5).to_a
=> [-1.0, -0.5, 0.0, 0.5, 1.0, 1.5, 2.0, 2.5]
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...
proper hibernate annotation for byte[]
...nds on what you want. JPA can persist a non annotated byte[]. From the JPA 2.0 spec:
11.1.6 Basic Annotation
The Basic annotation is the simplest
type of mapping to a database column.
The Basic annotation can be applied
to a persistent property or instance
variable of any of the fo...