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How to use a variable to specify column name in ggplot
...t will remain around for a long time).
The idiomatic way now would be to convert to a symbol the string that the variable contains, using sym()(which is almost the same as base aliases as.name() / as.symbol()), and unquote it using !!
Simulating OP's data we can do :
library(tidyverse)
rates.by....
Change Checkbox value without triggering onCheckChanged
...the solution. mListener is an implementation of the OnCheckChangedListener interface, which was created by the programmer. My answer implies that the programmer maintained a reference to their own implementation - mListener.
– Shade
Jul 9 '14 at 8:20
...
Why NSUserDefaults failed to save NSMutableDictionary in iOS?
...
When I need the data, I read out the NSData, and use NSKeyedUnarchiver to convert NSData back to the object.
It is a little cumbersome, because i need to convert to/from NSData everytime, but it just works.
Here is one example per request:
Save:
NSUserDefaults *defaults = [NSUserDefaults stand...
Defining custom attrs
...e.g, "@color/my_color", "@layout/my_layout")
color
boolean
dimension
float
integer
string
fraction
enum - normally implicitly defined
flag - normally implicitly defined
You can set the format to multiple types by using |, e.g., format="reference|color".
enum attributes can be defined as follows:
...
Swift: Pass array by reference?
... when I add a chat to account.chats , chatsViewController.chats still points to account.chats ). I.e., I don't want Swift to separate the two arrays when the length of account.chats changes.
...
How do I create a random alpha-numeric string in C++?
...;
#include <unistd.h>
using namespace std;
string gen_random(const int len) {
string tmp_s;
static const char alphanum[] =
"0123456789"
"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
"abcdefghijklmnopqrstuvwxyz";
srand( (unsigned) time(NULL) * getpid());
...
Check if all elements in a list are identical
...be infinite or just dynamically generated. You can only find its length by converting it to a list which takes away most of the iterators advantages
– Ivo van der Wijk
Oct 5 '10 at 5:51
...
Object-orientation in C
...sic level, you just use plain structs as objects and pass them around by pointers:
struct monkey
{
float age;
bool is_male;
int happiness;
};
void monkey_dance(struct monkey *monkey)
{
/* do a little dance */
}
To get things like inheritance and polymorphism, you have to work a l...
Determine if Android app is being used for the first time
...
SharedPreferences are maintained during upgrade. So, I assume that when its being upgraded from PlayStore, old value is available. In fact it is applicable for other methods i.e. checking existence of file too. So, shortcut method in that case is to...
Use of exit() function
...
Try using exit(0); instead. The exit function expects an integer parameter. And don't forget to #include <stdlib.h>.
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