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Why are quaternions used for rotations?
...s (despite the bizarre story that's occasionally told about Hamilton/Gibbs/etc). Physics requires that our descriptions have good analytic behavior (this has a precisely defined meaning, but in some rather technical ways that go far beyond what's taught in normal intro classes, so I won't go into an...
CASCADE DELETE just once
...traint on some_table and all tables that have constraints on those tables, etc.
Postgres supports CASCADE with TRUNCATE command:
TRUNCATE some_table CASCADE;
Handily this is transactional (i.e. can be rolled back), although it is not fully isolated from other concurrent transactions, and has sev...
In Python, how do I index a list with another list?
...ng, either by integer, slice or index-list:
class Flexlist(list):
def __getitem__(self, keys):
if isinstance(keys, (int, slice)): return list.__getitem__(self, keys)
return [self[k] for k in keys]
Which, for your example, you would use as:
L = Flexlist(['a', 'b', 'c', 'd', 'e...
In what situations would AJAX long/short polling be preferred over HTML5 WebSockets?
...m the fact that you would need to setup websocket on the server (handlers, etc.) There is simply no reason to use Long polling over websocket. Websocket is much faster (low latency) and allows the server to "talk" to the client without the client asking it to. Nowadays I use signalr (one of the best...
Change / Add syntax highlighting for a language in Sublime 2/3
...; Color Scheme. Themes highlight different keywords, functions, variables, etc. through the use of scopes, which are defined by a series of regular expressions contained in a .tmLanguage file in a language's directory/package. For example, the JavaScript.tmLanguage file assigns the scopes source.js ...
pyplot axes labels for subplots
... be created before ax1 and ax2, otherwise the big plot will cover up the small plots.
– 1''
Nov 29 '14 at 21:06
ax.gri...
How can I search (case-insensitive) in a column using LIKE wildcard?
... trees
WHERE trees.`title` COLLATE UTF8_GENERAL_CI LIKE '%elm%'
Actually, if you add COLLATE UTF8_GENERAL_CI to your column's definition, you can just omit all these tricks: it will work automatically.
ALTER TABLE trees
MODIFY COLUMN title VARCHAR(…) CHARACTER
SET UTF8 COLLATE UTF8_GE...
ng-repeat :filter by single field
..., looking at the union, rather than intersection?
– jetcom
Dec 30 '13 at 23:53
2
@jetcom, you'll ...
Awaiting multiple Tasks with different results
...nAll makes no difference to how the tasks run (concurrently, sequentially, etc). At the highest level, Task.WhenAll predates good compiler support for async/await, and was useful when those things didn't exist. It is also useful when you have an arbitrary array of tasks, rather than 3 discreet tasks...
How to make a Java Generic method static?
...urn value always introduce (declare) a new generic type variable.
Additionally, type variables between types (ArrayUtils) and static methods (appendToArray) never interfere with each other.
So, what does this mean:
In my answer <E> would hide the E from ArrayUtils<E> if the method woul...