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How to calculate the angle between a line and the horizontal axis?
...aX*deltaX+deltaY*deltaY)), unless the length is 0.
After that, deltaX will now be the cosine of the angle between the vector and the horizontal axis (in the direction from the positive X to the positive Y axis at P1).
And deltaY will now be the sine of that angle.
If the vector's length is 0, it won...
Running multiple AsyncTasks at the same time — not possible?
...llel computations for a bunch of AsyncTasks. But later they fixed that and now the size is 5, so at most 5 AsyncTasks can run simultaneously. Unfortunately I don't remember in what version exactly they changed that.
UPDATE:
Here is what current (2012-01-27) API says on this:
When first introdu...
Why does the expression 0 < 0 == 0 return False in Python?
...es check if 0 < 0 which obviously returns False onto the python stack.
Now notice line 11: JUMP_IF_FALSE_OR_POP 23
This means that if 0 < 0 returns False perform a jump to line 23.
Now, 0 < 0 is False, so the jump is taken, which leaves the stack with a False which is the return value for...
What happens to C# Dictionary lookup if the key does not exist?
...corresponding value
}
else
{
// Key wasn't in dictionary; "value" is now 0
}
(Using ContainsKey and then the the indexer makes it look the key up twice, which is pretty pointless.)
Note that even if you were using reference types, checking for null wouldn't work - the indexer for Dictionary...
Ignoring time zones altogether in Rails and PostgreSQL
...m the Postgres epoch, 2000-01-01 00:00:00 UTC.
Postgres also has built-in knowledge of the commonly used UNIX time counting seconds from the UNIX epoch, 1970-01-01 00:00:00 UTC, and uses that in functions to_timestamp(double precision) or EXTRACT(EPOCH FROM timestamptz).
The source code:
* Timestam...
Declaring abstract method in TypeScript
...e property is marked as protected. This was added in TypeScript 1.3 and is now firmly established.
The makeSound method is marked as abstract, as is the class. You cannot directly instantiate an Animal now, because it is abstract. This is part of TypeScript 1.6, which is now officially live.
abstr...
How do I test if a variable is a number in Bash?
... such contexts, you don't need to shopt extglob... that's a good thing to know!
– gniourf_gniourf
Feb 13 '15 at 19:49
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Decimal number regular expression, where digit after decimal is optional
...
Thanks Pete, well spotted. The answer has now been corrected, by adding extra parenthesis so it behaves as intended. It is now written like ^A?(B|C)$. Previously, it was written like ^A?B|C$ which actually means (^A?B)|(C$) which was incorrect. Note: ^(A?B|C)$ is als...
How do I create a list of random numbers without duplicates?
...f r not in answer:
answerSize += 1
answer.add(r)
# answer now contains 10 unique, random integers from 0.. 100
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Convert SVG to image (JPEG, PNG, etc.) in the browser
...
You can now use the JavaScript SVG library Pablo to achieve this (I made it). See the toImage() and also download() for an auto-downloaded image.
– Premasagar
Sep 15 '14 at 14:04
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