大约有 40,000 项符合查询结果（耗时：0.0783秒） [XML]
Relative frequencies / proportions with dplyr
... 4 1 5 5 0.3846154
From the dplyr vignette:
When you group by multiple variables, each summary peels off one level of the grouping. That makes it easy to progressively roll-up a dataset.
Thus, after the summarise, the last grouping variable specified in group_by, 'gear', is peeled off. ...
Align two inline-blocks left and right on same line
...ce I answered this question and I guess a more modern solution is needed, although the current one does the thing :)
1.Flexbox
It's by far the shortest and most flexible. Apply display: flex; to the parent container and adjust the placement of its children by justify-content: space-between; like t...
Applicatives compose, monads don't
...
If we compare the types
(<*>) :: Applicative a => a (s -> t) -> a s -> a t
(>>=) :: Monad m => m s -> (s -> m t) -> m t
we get a clue to what separates the two concepts. That (s -> m t) in the type of (&g...
How To: Best way to draw table in console app (C#)
...ays with this simple API:
static void Main(string[] args)
{
IEnumerable<Tuple<int, string, string>> authors =
new[]
{
Tuple.Create(1, "Isaac", "Asimov"),
Tuple.Create(2, "Robert", "Heinlein"),
Tuple.Create(3, "Frank", "Herbert"),
Tuple.Create(4, "Aldous...
How to simulate Android killing my process
...is to work. For those wondering where the doc quotes came from it's here. Although I'm not sure they're actually related to the topic since it's about the <activity> tag in the manifest.
– Tony Chan
Apr 24 '14 at 2:23
...
How do I set environment variables from Java?
...ctor out a method
void setUpEnvironment(ProcessBuilder builder) {
Map<String, String> env = builder.environment();
// blah blah
}
and pass any ProcessBuilders through it before starting them.
Also, you probably already know this, but you can start more than one process with the sam...
Best way to create an empty map in Java
... be immutable:
Collections.emptyMap()
// or, in some cases:
Collections.<String, String>emptyMap()
You'll have to use the latter sometimes when the compiler cannot automatically figure out what kind of Map is needed (this is called type inference). For example, consider a method declared l...
Could not load file or assembly 'Newtonsoft.Json' or one of its dependencies. Manifest definition do
...sed the same version by running the following command and checking the results:
update-package Newtonsoft.Json -reinstall
And, lastly I removed the following from my web.config:
<dependentAssembly>
<assemblyIdentity name="Newtonsoft.Json" publicKeyToken="30ad4fe6b2a6aeed" culture=...
Is it possible to append to innerHTML without destroying descendants' event listeners?
...It's a simple one-line replacement for .innerHTML.
var html_to_insert = "<p>New paragraph</p>";
// with .innerHTML, destroys event listeners
document.getElementById('mydiv').innerHTML += html_to_insert;
// with .insertAdjacentHTML, preserves event listeners
document.getElementById('my...
How to change app name per Gradle build type
...
If by "app name", you mean android:label on <application>, the simplest solution is to have that point at a string resource (e.g., android:label="@string/app_name"), then have a different version of that string resource in a src/debug/ sourceset.
You can see that...