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How to open, read, and write from serial port in C?
I am a little bit confused about reading and writing to a serial port. I have a USB device in Linux that uses the FTDI USB serial device converter driver. When I plug it in, it creates: /dev/ttyUSB1.
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Why is SSE scalar sqrt(x) slower than rsqrt(x) * x?
I've been profiling some of our core math on an Intel Core Duo, and while looking at various approaches to square root I've noticed something odd: using the SSE scalar operations, it is faster to take a reciprocal square root and multiply it to get the sqrt, than it is to use the native sqrt opcode!...
Undefined method 'task' using Rake 0.9.0
I just updated Rake to the latest version ( 0.9.0.beta.4 ) and the rake command ends up with the following error message:
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CSS Background Opacity [duplicate]
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Children inherit opacity. It'd be weird and inconvenient if they didn't.
You can use a translucent PNG file for your background image, or use an RGBa (a for alpha) color for your background color.
Example, 50% faded black background:
<div style="backgroun...
Create an index on a huge MySQL production table without table locking
...ed to create an index on a ~5M rows MySQL table. It is a production table, and I fear a complete block of everything if I run a CREATE INDEX statement...
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javascript: recursive anonymous function?
...ive the function a name, even when you're creating the function as a value and not a "function declaration" statement. In other words:
(function foo() { foo(); })();
is a stack-blowing recursive function. Now, that said, you probably don't may not want to do this in general because there are som...
Difference between DateTime and Time in Ruby
What's the difference between DateTime and Time classes in Ruby and what factors would cause me to choose one or the other?
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Numpy first occurrence of value greater than existing value
I have a 1D array in numpy and I want to find the position of the index where a value exceeds the value in numpy array.
7 A...
Do you use NULL or 0 (zero) for pointers in C++?
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Here's Stroustrup's take on this: C++ Style and Technique FAQ
In C++, the definition of NULL is 0, so there is only an aesthetic difference. I prefer to avoid macros, so I use 0. Another problem with NULL is that people sometimes mistakenly believe that it is differen...
Is R's apply family more than syntactic sugar?
...regarding execution time and / or memory.
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