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how does multiplication differ for NumPy Matrix vs Array classes?
... rules of linear algebra
some code snippets to illustrate:
>>> from numpy import linalg as LA
>>> import numpy as NP
>>> a1 = NP.matrix("4 3 5; 6 7 8; 1 3 13; 7 21 9")
>>> a1
matrix([[ 4, 3, 5],
[ 6, 7, 8],
[ 1, 3, 13],
[ 7, 21, 9...
Stop Mongoose from creating _id property for sub-document array items
If you have subdocument arrays, Mongoose automatically creates ids for each one. Example:
6 Answers
...
What is this date format? 2011-08-12T20:17:46.384Z
...
The T is just a literal to separate the date from the time, and the Z means "zero hour offset" also known as "Zulu time" (UTC). If your strings always have a "Z" you can use:
SimpleDateFormat format = new SimpleDateFormat(
"yyyy-MM-dd'T'HH:mm:ss.SSS'Z'", Locale.US)...
What is null in Java?
...languages). Note also that by contract, it also has this special property (from java.lang.Object):
public boolean equals(Object obj)
For any non-null reference value x, x.equals(null) should return false.
It is also the default value (for variables that have them) for all reference types...
What exactly is OAuth (Open Authorization)?
...ire list of friends, calendar and what not.
It allows you to manage access from the resource provider's application. If the third-party application does not provide mechanism for cancelling access, you would be stuck with them having access to your information. With OAuth, there is provision for rev...
Is there a constraint that restricts my generic method to numeric types?
...olation of the DRY principle. The DRY principle is there to prevent people from duplicating code in multiple places that would cause the application to become hard to maintain.
This is not at all the case here: if you want a change then you can just change the template (a single source for all your...
How to return multiple objects from a Java method?
I want to return two objects from a Java method and was wondering what could be a good way of doing so?
25 Answers
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Token Authentication vs. Cookies
...kie in every response back to the client. This means the next request made from the client will include this cookie and will thus be recognized by the server. This way the server can maintain a session with the stateless client, knowing mostly everything about the app's state, but stored in the serv...
What is the difference between atomic and critical in OpenMP?
... if this will not change. (Visual Studio 2012 has an OpenMP implementation from March 2002.) To quote MSDN:
The expression statement must have one of the following forms:
xbinop=expr
x++
++x
x--
--x
In the preceding expressions: x is an lvalue expression with scal...
Why can't C# interfaces contain fields?
...tic level, I find it interesting to also approach these sorts of questions from the implementation details level.
An interface can be thought of as a collection of slots, which contain methods. When a class implements an interface, the class is required to tell the runtime how to fill in all the re...