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Calculate the center point of multiple latitude/longitude coordinate pairs
...ing them has weird edge cases with angles when they wrap from 359' back to 0'.
A much earlier question on SO asked about finding the average of a set of compass angles.
An expansion of the approach recommended there for spherical coordinates would be:
Convert each lat/long pair into a unit-lengt...
What is a method that can be used to increment letters?
...
180
Simple, direct solution
function nextChar(c) {
return String.fromCharCode(c.charCodeAt(0) +...
Why does this code using random strings print “hello world”?
...onstructed with a specific seed parameter (in this case -229985452 or -147909649), it follows the random number generation algorithm beginning with that seed value.
Every Random constructed with the same seed will generate the same pattern of numbers every time.
...
How to send a simple string between two programs using pipes?
... "/tmp/myfifo";
/* create the FIFO (named pipe) */
mkfifo(myfifo, 0666);
/* write "Hi" to the FIFO */
fd = open(myfifo, O_WRONLY);
write(fd, "Hi", sizeof("Hi"));
close(fd);
/* remove the FIFO */
unlink(myfifo);
return 0;
}
reader.c
#include <fcntl.h>
#i...
Return 0 if field is null in MySQL
...
Use IFNULL:
IFNULL(expr1, 0)
From the documentation:
If expr1 is not NULL, IFNULL() returns expr1; otherwise it returns expr2. IFNULL() returns a numeric or string value, depending on the context in which it is used.
...
Find the extension of a filename in Ruby
...
That's really basic stuff:
irb(main):002:0> accepted_formats = [".txt", ".pdf"]
=> [".txt", ".pdf"]
irb(main):003:0> File.extname("example.pdf") # get the extension
=> ".pdf"
irb(main):004:0> accepted_formats.include? File.extname("example.pdf")
=...
On localhost, how do I pick a free port number?
...do I figure out which port is available? I assume I cannot listen on port 80 or 21?
5 Answers
...
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:
...
How does the const constructor actually work?
... |
edited Aug 18 '14 at 20:51
superEb
4,9153030 silver badges3838 bronze badges
answered Feb 13 '14 at ...
seek() function?
...many positions you will move; from_what defines your point of reference:
0: means your reference point is the beginning of the file
1: means your reference point is the current file position
2: means your reference point is the end of the file
if omitted, from_what defaults to 0.
Never forget t...