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Speed up the loop operation in R
...rote a function that iterates over a data.frame object. It simply adds a new column to a data.frame and accumulates something. (simple operation). The data.frame has roughly 850K rows. My PC is still working (about 10h now) and I have no idea about the runtime.
...
How to use Comparator in Java to sort
...args) {
List<Person> people = Arrays.asList(
new Person("Joe", 24),
new Person("Pete", 18),
new Person("Chris", 21)
);
Collections.sort(people, new LexicographicComparator());
System.out.println(people);
Co...
Update R using RStudio
...
You install a new version of R from the official website.
RStudio should automatically start with the new version when you relaunch it.
In case you need to do it manually, in RStudio, go to :Tools -> options -> General.
Check @mic...
How to serialize SqlAlchemy result to JSON?
...ou could use:
from sqlalchemy.ext.declarative import DeclarativeMeta
def new_alchemy_encoder():
_visited_objs = []
class AlchemyEncoder(json.JSONEncoder):
def default(self, obj):
if isinstance(obj.__class__, DeclarativeMeta):
# don't re-visit self
...
Download multiple files with a single action
...at. But browsers don't portably parse multipart responses from the server side, but technically there's nothing difficult with doing this.
– CMCDragonkai
Jul 27 '18 at 4:25
2
...
The Role Manager feature has not been enabled
...
If you got here because you're using the new ASP.NET Identity UserManager, what you're actually looking for is the RoleManager:
var roleManager = new RoleManager<IdentityRole>(new RoleStore<IdentityRole>(new ApplicationDbContext()));
roleManager will ...
implements Closeable or implements AutoCloseable
...d do this in a finally block:
PrintWriter pw = null;
try {
File file = new File("C:\\test.txt");
pw = new PrintWriter(file);
} catch (IOException e) {
System.out.println("bad things happen");
} finally {
if (pw != null) {
try {
pw.close();
} catch (IOException e) {
...
What are the differences between “git commit” and “git push”?
...
Remote repository: repository on a server (Github).
git commit: Append a new commit (last commit + staged modifications) to the local repository. (All commits are stored in /.git)
git push, git pull: Sync the local repository with its associated remote repository. push - apply changes from loca...
CryptographicException 'Keyset does not exist', but only through WCF
...
blowdartblowdart
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...
PHP PDO: charset, set names?
... you're running an older version of PHP, you must do it like this:
$dbh = new PDO("mysql:$connstr", $user, $password);
$dbh->exec("set names utf8");
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