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How to check BLAS/LAPACK linkage in NumPy and SciPy?
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The method numpy.show_config() (or numpy.__config__.show()) outputs information about linkage gathered at build time. My output looks like this. I think it means I am using the BLAS/LAPACK that ships with Mac OS.
>>> import numpy as np...
Structure padding and packing
...It inserts the following "gaps" into your first structure:
struct mystruct_A {
char a;
char gap_0[3]; /* inserted by compiler: for alignment of b */
int b;
char c;
char gap_1[3]; /* -"-: for alignment of the whole struct in an array */
} x;
Packing, on the other hand prevents ...
Finding the index of an item in a list
...atch, you can give index a hint. For instance, in this snippet, l.index(999_999, 999_990, 1_000_000) is roughly five orders of magnitude faster than straight l.index(999_999), because the former only has to search 10 entries, while the latter searches a million:
>>> import timeit
>>&g...
How to set or change the default Java (JDK) version on OS X?
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First run /usr/libexec/java_home -V which will output something like the following:
Matching Java Virtual Machines (3):
1.8.0_05, x86_64: "Java SE 8" /Library/Java/JavaVirtualMachines/jdk1.8.0_05.jdk/Contents/Home
1.6.0_65-b14-462, x86_64: "Java SE...
Which $_SERVER variables are safe?
...lue comes from and hence whether it can be trusted for a certain purpose. $_SERVER['HTTP_FOOBAR'] for example is entirely safe to store in a database, but I most certainly wouldn't eval it.
As such, let's divide those values into three categories:
Server controlled
These variables are set by the ...
string sanitizer for filename
...are happy to be used? For example, you could allow just good ol' a-z, 0-9, _, and a single instance of a period (.). That's obviously more limiting than most filesystems, but should keep you safe.
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What's the cleanest way of applying map() to a dictionary in Swift?
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Swift 4+
Good news! Swift 4 includes a mapValues(_:) method which constructs a copy of a dictionary with the same keys, but different values. It also includes a filter(_:) overload which returns a Dictionary, and init(uniqueKeysWithValues:) and init(_:uniquingKeysWith:) ini...
Difference between reduce and foldLeft/fold in functional programming (particularly Scala and Scala
...ase of foldLeft
scala> val intParList: ParSeq[Int] = (1 to 100000).map(_ => scala.util.Random.nextInt()).par
scala> timeMany(1000, intParList.reduce(_ + _))
Took 462.395867 milli seconds
scala> timeMany(1000, intParList.foldLeft(0)(_ + _))
Took 2589.363031 milli seconds
reduce vs fo...
How do I parse an ISO 8601-formatted date?
... and are okay to tolerate occasional misreads.
– ivan_pozdeev
Apr 23 '15 at 23:34
2
Agreed. An ex...
Unix's 'ls' sort by name
...in some cases (for instance, %foo will sort between bar and quux in LANG=en_US). If you want an ASCIIbetical sort, use
LANG=C ls
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