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Apply a function to every row of a matrix or a data frame
... 3 4
[3,] 5 6
R> apply(M, 1, function(x) 2*x[1]+x[2])
[1] 4 10 16
R>
This takes a matrix and applies a (silly) function to each row. You pass extra arguments to the function as fourth, fifth, ... arguments to apply().
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How to validate date with format “mm/dd/yyyy” in JavaScript?
...rs
var parts = dateString.split("/");
var day = parseInt(parts[1], 10);
var month = parseInt(parts[0], 10);
var year = parseInt(parts[2], 10);
// Check the ranges of month and year
if(year < 1000 || year > 3000 || month == 0 || month > 12)
return false;
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Testing if object is of generic type in C#
... A A LIST? That question seems hard to answer.
– user1086498
May 9 '13 at 20:09
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How can I check if an ip is in a network in Python?
...t == net
address = dottedQuadToNum("192.168.1.1")
networka = networkMask("10.0.0.0",24)
networkb = networkMask("192.168.0.0",24)
print (address,networka,networkb)
print addressInNetwork(address,networka)
print addressInNetwork(address,networkb)
This outputs:
False
True
If you just want a singl...
Programmatically find the number of cores on a machine
...CPU = sysinfo.dwNumberOfProcessors;
Linux, Solaris, AIX and Mac OS X >=10.4 (i.e. Tiger onwards)
int numCPU = sysconf(_SC_NPROCESSORS_ONLN);
FreeBSD, MacOS X, NetBSD, OpenBSD, etc.
int mib[4];
int numCPU;
std::size_t len = sizeof(numCPU);
/* set the mib for hw.ncpu */
mib[0] = CTL_HW;
mib[1...
What is the EAFP principle in Python?
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answered Jul 6 '12 at 10:56
Sven MarnachSven Marnach
446k100100 gold badges833833 silver badges753753 bronze badges
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How can I do DNS lookups in Python, including referring to /etc/hosts?
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answered May 10 '10 at 18:36
Jochen RitzelJochen Ritzel
89.3k2525 gold badges181181 silver badges180180 bronze badges
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How to redirect output to a file and stdout
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“INSERT IGNORE” vs “INSERT … ON DUPLICATE KEY UPDATE”
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1003
I would recommend using INSERT...ON DUPLICATE KEY UPDATE.
If you use INSERT IGNORE, then the...
What are deferred objects?
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101
Deferred Object
As of jQuery 1.5, the Deferred object provides a way to register multiple call...