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Programmatically find the number of cores on a machine
...umCPU = 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] = HW_AVAILCPU; // alternatively, try HW_NCPU;
/* get the number of CPUs from the system */
sysctl(mib, ...
How to Correctly Use Lists in R?
...where the first element is a character vector, the second is a data frame, etc. In this case, you have created two different lists. x has four vectors, each of length 1. x2 has 1 vector of length 4:
> length(x[[1]])
[1] 1
> length(x2[[1]])
[1] 4
So these are completely different lists.
R l...
JavaScript check if variable exists (is defined/initialized)
...(Assuming the variable could hold anything (string, int, object, function, etc.))
28 Answers
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Extract hostname name from string
...uld be considered the root domain (i.e. www.食狮.公司.cn, b.c.kobe.jp, etc.). Read more about it here.
Try:
npm install --save psl
Then with my "extractHostname" implementation run:
let psl = require('psl');
let url = 'http://www.youtube.com/watch?v=ClkQA2Lb_iE';
psl.get(extractHostname(url...
Is there a list of screen resolutions for all Android based phones and tablets? [closed]
...s with larger aspect ratio.
Most likely, you would instead design it to stretch over the 1.333 to 1.778 range. But sometimes part of your design looks too distorted then.
Advanced layout ideas:
For text, you can design for 1.3333, then increase line spacing for 1.666 - though that will loo...
Why doesn't Java allow overriding of static methods?
... are attached to an instance while static methods are attached to a class, etc etc. Still, consider the following code:
public class RegularEmployee {
private BigDecimal salary;
public void setSalary(BigDecimal salary) {
this.salary = salary;
}
public static BigDecimal get...
C# Lambda expressions: Why should I use them?
...# expressions in to the SQL expressions desired for filtering / ordering / etc. on the server side.
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notifyDataSetChanged example
I'm trying to use in my Android Application the notifyDataSetChanged() method for an ArrayAdapter but it doesn't work for me.
...
R object identification
...t(d=1:26, e=letters))
data(cars)
obj <- lm(dist ~ speed, data=cars)
..etc.
If obj is an S3 or S4 object, you can also try methods or showMethods, showClass, etc. Patrick Burns' R Inferno has a pretty good section on this (sec #7).
EDIT: Dirk and Hadley mention str(obj) in their answers. It ...
Difference between app.use and app.get in express.js
...l of them and regardless of HTTP verb used:
GET /
PUT /foo
POST /foo/bar
etc.
app.get(), on the other hand, is part of Express' application routing and is intended for matching and handling a specific route when requested with the GET HTTP verb:
GET /
And, the equivalent routing for your exa...