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How to remove last n characters from every element in the R vector
... an example of what I would do. I hope it's what you're looking for.
char_array = c("foo_bar","bar_foo","apple","beer")
a = data.frame("data"=char_array,"data2"=1:4)
a$data = substr(a$data,1,nchar(a$data)-3)
a should now contain:
data data2
1 foo_ 1
2 bar_ 2
3 ap 3
4 b 4
...
When to use reinterpret_cast?
...time hence the word static . This is the cast the C++ compiler uses internally for implicit casts also.
11 Answers
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How to fix the “java.security.cert.CertificateException: No subject alternative names present” error
...ager that does not validate certificate chains
TrustManager[] trustAllCerts = new TrustManager[] {new X509TrustManager() {
public java.security.cert.X509Certificate[] getAcceptedIssuers() {
return null;
}
public void checkClientTrusted(X509...
Hide keyboard when scroll UITableView
...to our UITableViewController class
override func scrollViewDidScroll(_ scrollView: UIScrollView) {
if !tableView.isDecelerating {
view.endEditing(true)
}
}
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Get generated id after insert
...LiteDatabase().insert("user", "", values) ;
If query exec use select last_insert_rowid()
String sql = "INSERT INTO [user](firstName,lastName) VALUES (\"Ahmad\",\"Aghazadeh\"); select last_insert_rowid()";
DBHelper itemType =new DBHelper();// your dbHelper
c = db.rawQuery(sql, null);
if (c.move...
Best way to store date/time in mongodb
...ISODate()})
> db.test.insert({date: new Date()})
> db.test.find()
{ "_id" : ObjectId("..."), "date" : ISODate("2014-02-10T10:50:42.389Z") }
{ "_id" : ObjectId("..."), "date" : ISODate("2014-02-10T10:50:57.240Z") }
The native type supports a whole range of useful methods out of the box, which...
Run an OLS regression with Pandas Data Frame
... I accidentally typed formulas instead and got weird error: TypeError: from_formula() takes at least 3 arguments (2 given)
– denfromufa
Nov 14 '16 at 18:19
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Different font size of strings in the same TextView
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is there a way to move the characters which are small to the center in the vertical direction? Basically all the characters should be vertically centered regardless of the size.
– 500865
Sep 23 '16 at 22:16
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SQL Server: SELECT only the rows with MAX(DATE)
... HAVING t1.DateEntered = MAX(t2.DateEntered))
This is the fastest of all the queries supplied above. The query cost came in at 0.0070668.
The preferred answer above, by Mikael Eriksson, has a query cost of 0.0146625
You may not care about the performance for such a small sample, but in large...
Multiple returns from a function
...
Technically, you can't return more than one value. However, there are multiple ways to work around that limitation. The way that acts most like returning multiple values, is with the list keyword:
function getXYZ()
{
return arr...