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How to calculate cumulative normal distribution?
...
Here's an example:
>>> from scipy.stats import norm
>>> norm.cdf(1.96)
0.9750021048517795
>>> norm.cdf(-1.96)
0.024997895148220435
In other words, approximately 95% of the standard normal interval lies with...
Difference between Django's annotate and aggregate methods?
...rage_price': 34.35}
Returns a dictionary containing the average price of all books in the queryset.
Annotation
>>> q = Book.objects.annotate(num_authors=Count('authors'))
>>> q[0].num_authors
2
>>> q[1].num_authors
1
q is the queryset of books, but each book has been...
When is del useful in python?
I can't really think of any reason why python needs the del keyword (and most languages seem to not have a similar keyword). For instance, rather than deleting a variable, one could just assign None to it. And when deleting from a dictionary, a del method could be added.
...
Remove a string from the beginning of a string
...
Plain form, without regex:
$prefix = 'bla_';
$str = 'bla_string_bla_bla_bla';
if (substr($str, 0, strlen($prefix)) == $prefix) {
$str = substr($str, strlen($prefix));
}
Takes: 0.0369 ms (0.000,036,954 seconds)
And with:
$prefix = 'bla_';
$str = 'bla_string...
Converting JSONarray to ArrayList
...n the github gist.github.com/codebutler/2339666
– inexcii
Aug 27 '14 at 1:54
2
Why not use an Arr...
Build query string for System.Net.HttpClient get
...olve building a name value collection and url encoding
those and then finally concatenating them?
Sure:
var query = HttpUtility.ParseQueryString(string.Empty);
query["foo"] = "bar<>&-baz";
query["bar"] = "bazinga";
string queryString = query.ToString();
will give you the expected re...
Any way to write a Windows .bat file to kill processes? [closed]
...out of my IDE. Yes, these are processes from programs that my company installs on my machine for security and compliance. What I'd like to do is have a .bat file or script of some kind with which I can kill the processes in question.
...
C++: How to round a double to an int? [duplicate]
I have a double (call it x), meant to be 55 but in actuality stored as 54.999999999999943157 which I just realised.
5 Answe...
How to generate an entity-relationship (ER) diagram using Oracle SQL Developer
... is exported. To export in a vector format, use To PDF File, instead. This allows for simplified editing using Inkscape (or other vector image editor).
These instructions may work for SQL Developer 3.2.09.23 to 4.1.3.20.
sh...
Best way to randomize an array with .NET
...e: as used in my example, Random() is perfectly thread-safe, unless you're allowing the routine in which you randomize the array to be re-entered, in which case you'll need something like lock (MyRandomArray) anyway in order not to corrupt your data, which will protect rnd as well.
Also, it should b...