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Group by multiple columns in dplyr, using string vector input
...orm(100)
)
# Columns you want to group by
grp_cols <- names(df)[-3]
# Convert character vector to list of symbols
dots <- lapply(grp_cols, as.symbol)
# Perform frequency counts
df %>%
group_by_(.dots=dots) %>%
summarise(n = n())
output:
Source: local data frame [9 x 3]
Grou...
Does Typescript support the ?. operator? (And, what's it called?)
..., including the type conversions such as...
var n: number = +myString; // convert to number
var b: bool = !!myString; // convert to bool
Manual Solution
But back to the question. I have an obtuse example of how you can do a similar thing in JavaScript (and therefore TypeScript) although I'm defi...
MySql: Tinyint (2) vs tinyint(1) - what is the difference?
I knew boolean in mysql as tinyint (1) .
4 Answers
4
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Animate change of view background color on Android
...ce this TransitionDrawable in the android:background attribute.
At this point you can initiate the transition in your code on-command by doing:
TransitionDrawable transition = (TransitionDrawable) viewObj.getBackground();
transition.startTransition(transitionTime);
Or run the transition in rever...
android: move a view on touch move (ACTION_MOVE)
...mplements View.OnTouchListener {
TextView _view;
ViewGroup _root;
private int _xDelta;
private int _yDelta;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
_root = (ViewGroup)findViewById(R.id.root);
_...
Swift equivalent for MIN and MAX macros
...to type it up in Xcode and check out the Swift header. If you type let a : Int = 5 and Command + Click on Int, you get to see cool stuff!
– Jack
Jun 12 '14 at 14:37
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How do I get the first n characters of a string without checking the size or going out of bounds?
...substring_safe, like paxdiablo's answer, so that usage is easier to read / intent more obvious.
– ToolmakerSteve
Aug 20 '14 at 5:17
...
Example: Communication between Activity and Service using Messaging
... an instance of itself to consumers who call onBind. Then you can directly interact with the service, e.g. registering your own listener interface with the service, so that you can get callbacks.
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What is the difference between Type and Class?
...lass defines how the
object is implemented .The class
defines object's internal state and
the implementation of its
operations.
In contrast, an object's
type only refers to its interface - a
set of requests to which it can
respond.
An object can have many types,
and objects...
How to call Android contacts list?
...hen return to my app with the contact's name. Here's the code I got on the internet, but it doesnt work.
13 Answers
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