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Filter rows which contain a certain string
...iously filter_at. The advantage is that you can easily extend to more than one column.
Below also a solution with filter_all in order to find the string in any column,
using diamonds as example, looking for the string "V"
library(tidyverse)
String in only one column
# for only one column... extenda...
When to use in vs ref vs out
Someone asked me the other day when they should use the parameter keyword out instead of ref . While I (I think) understand the difference between the ref and out keywords (that has been asked before ) and the best explanation seems to be that ref == in and out , what are some (hypothet...
Create a custom callback in JavaScript
...back.apply(this, ['Hi', 3, 2, 1]);
}
function foo(salutation, three, two, one) {
alert(salutation + " " + this.name + " - " + three + " " + two + " " + one);
}
var t = new Thing('Joe');
t.doSomething(foo); // Alerts "Hi Joe - 3 2 1" via `foo`
...
Recursion in Angular directives
...opular recursive angular directive Q&A's out there, which all come down to one of the following solutions:
9 Answers
...
How do synchronized static methods work in Java and can I use it for loading Hibernate entities?
... table T.
With your approach the only thing you're getting is to make sure one is called after the other, when this would happen anyway in the DB, because the RDBMS will prevent them from inserting half information from A and half from B at the same time. The result will be the same but only 5 times...
How can I copy the output of a command directly into my clipboard?
... easy way of doing it. I wrote down the complete procedure just in case anyone else needs it.
First install a 16 kB program called xclip:
sudo apt-get install xclip
You can then pipe the output into xclip to be copied into the clipboard:
cat file | xclip
To paste the text you just copied, yo...
'const int' vs. 'int const' as function parameters in C++ and C
... a constant integer. Neither "a" nor "*a" can be assigned to.
static int one = 1;
int testfunc3 (const int *a)
{
*a = 1; /* Error */
a = &one;
return *a;
}
int testfunc4 (int * const a)
{
*a = 1;
a = &one; /* Error */
return *a;
}
int testfunc5 (const int * const a)
{
*a =...
Is file append atomic in UNIX?
...d to a file in UNIX from multiple processes? Is it possible to lose data (one process overwriting the other's changes)? Is it possible for data to get mangled? (For example, each process is appending one line per append to a log file, is it possible that two lines get mangled?) If the append is ...
Eclipse IDE for Java - Full Dark Theme
...actually looks OK on Windows. You might need to change the system theme to one that uses similar colours for windows etc (e.g. download.microsoft.com/download/1/7/A/… for win 7 users) but you are 99% of the way there with just the defaults they give you, and there are additional tweeks listed in t...
Upgrading PHP in XAMPP for Windows?
...dblankspaces are you a xampp user? I thought it was perfectly clear for anyone who uses xampp... Still, my upvote goes to Dharmang, he answered earlier and with more precision, what if I want to stick with the same versions of Apache and MySql and just update PHP? This lazy (but clear) answer doesn'...