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How does BLAS get such extreme performance?
...e optimization. This boost significantly exceeds the second boost from parallelism and other hardware optimizations.
By the way, most (or even all) of the high performance BLAS implementations are NOT implemented in Fortran. ATLAS is implemented in C. GotoBLAS/OpenBLAS is implemented in C and i...
Check if all elements in a list are identical
... = next(iterator)
except StopIteration:
return True
return all(first == rest for rest in iterator)
One-liner:
def checkEqual2(iterator):
return len(set(iterator)) <= 1
Also one-liner:
def checkEqual3(lst):
return lst[1:] == lst[:-1]
The difference between the 3 versi...
Which SQL query is faster? Filter on Join criteria or Where clause?
...
Performance-wise, they are the same (and produce the same plans)
Logically, you should make the operation that still has sense if you replace INNER JOIN with a LEFT JOIN.
In your very case this will look like this:
SELECT *
FROM TableA a
LEFT JOIN
TableXRef x
ON x.TableAID = ...
Python extract pattern matches
...h a standard python REPL, the last result is stored in a special variable called _. It isn't valid outside anywhere else.
– UltraInstinct
Mar 13 '19 at 2:25
...
Installing older version of R package
...
To install an older version of a package from source (within R):
packageurl <- "http://cran.r-project.org/src/contrib/Archive/ggplot2/ggplot2_0.9.1.tar.gz"
install.packages(packageurl, repos=NULL, type="source")
If this doesn'...
How do I get indices of N maximum values in a NumPy array?
...t been able to find one.
If this solution turns out to be too slow (especially for small n), it may be worth looking at coding something up in Cython.
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PHP: Convert any string to UTF-8 without knowing the original character set, or at least try
I have an application that deals with clients from all over the world, and, naturally, I want everything going into my databases to be UTF-8 encoded.
...
Disable migrations when running unit tests in Django 1.7
... syncdb did in 1.6. I defined a new settings module just for unit
tests called "settings_test.py", which imports * from the main
settings module and adds this line:
MIGRATION_MODULES = {"myapp": "myapp.migrations_not_used_in_tests"}
Then I run tests like this:
DJANGO_SETTINGS_MODU...
Why can I access TypeScript private members when I shouldn't be able to?
...bers in TypeScript, and I find it a little confusing. Intellisense doesn't allow to access private member, but in pure JavaScript, it's all there. This makes me think that TS doesn't implement private members correctly.
Any thoughts?
...
How to compile a static library in Linux?
...:
target: prerequisites - the rule head
$@ - means the target
$^ - means all prerequisites
$< - means just the first prerequisite
ar - a Linux tool to create, modify, and extract from archives see the man pages for further information. The options in this case mean:
r - replace files existing...