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How to create GUID / UUID?
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Actually, the RFC allows for UUIDs that are created from random numbers. You just have to twiddle a couple of bits to identify it as such. See section 4.4. Algorithms for Creating a UUID from Truly Random or Pseudo-Random Numbers: rfc-archive.org/getrfc.php?rfc=4122
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Editing legend (text) labels in ggplot
... the ggplot2 package.
An example with your data:
# transforming the data from wide to long
library(reshape2)
dfm <- melt(df, id = "TY")
# creating a scatterplot
ggplot(data = dfm, aes(x = TY, y = value, color = variable)) +
geom_point(size=5) +
labs(title = "Temperatures\n", x = "TY [°C]...
What's the deal with a leading underscore in PHP class methods?
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It's from the bad old days of Object Oriented PHP (PHP 4). That implementation of OO was pretty bad, and didn't include things like private methods. To compensate, PHP developers prefaced methods that were intended to be private...
How do I detect whether a Python variable is a function?
...ect you're right that it doesn't for the original question, but that's far from certain.
– Chris B.
Mar 9 '09 at 5:33
6
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Can virtual functions have default parameters?
...iding function in a derived
class does not acquire default arguments from the function it
overrides. Example:
struct A {
virtual void f(int a = 7);
};
struct B : public A {
void f(int a);
};
void m()
{
B* pb = new B;
A* pa = pb;
pa->f(); //OK, calls pa->B::f(7)
pb->f();...
Reverse colormap in matplotlib
...lotlib.colors provides a function ListedColormap() to generate a color map from a list. So you can reverse any color map by doing
colormap_r = ListedColormap(colormap.colors[::-1])
share
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improv...
Malloc vs new — different padding
...malloc" or "padded like new"? That might give clues to where the idea came from.
Maybe he's confused, but maybe the code he's talking about is more than a straight difference between malloc(sizeof(Foo) * n) vs new Foo[n]. Maybe it's more like:
malloc((sizeof(int) + sizeof(char)) * n);
vs.
struc...
How do I know if a generator is empty from the start?
...w the programmer to ask whether there is another value without removing it from the "queue" if there is. There is such thing as single peek-ahead without requiring "backward traversal". That's not to say an iterator design must supply such a feature, but it sure is useful. Maybe you're objecting on ...
C# How can I check if a URL exists/is valid?
...test a URL without the cost of downloading the content:
// using MyClient from linked post
using(var client = new MyClient()) {
client.HeadOnly = true;
// fine, no content downloaded
string s1 = client.DownloadString("http://google.com");
// throws 404
string s2 = client.Downloa...
How to exit in Node.js
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Call the global process object's exit method:
process.exit()
From the docs:
process.exit([exitcode])
Ends the process with the specified code. If omitted, exit uses the 'success' code 0.
To exit with a 'failure' code:
process.exit(1);
The shell that executed node should see the exit ...