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Selecting only numeric columns from a data frame
...list-apply functions:
nums <- unlist(lapply(x, is.numeric))
Then standard subsetting
x[ , nums]
## don't use sapply, even though it's less code
## nums <- sapply(x, is.numeric)
For a more idiomatic modern R I'd now recommend
x[ , purrr::map_lgl(x, is.numeric)]
Less codey, less ref...
Add new field to every document in a MongoDB collection
...to add a new_field to all your collection, you have to use empty selector, and set multi flag to true (last param) to update all the documents
db.your_collection.update(
{},
{ $set: {"new_field": 1} },
false,
true
)
EDIT:
In the above example last 2 fields false, true specifies the upser...
Angularjs - display current date
I got a view in angularjs and I'm just trying to display the current date(formatted). I thought something like <span>{{Date.now() | date:'yyyy-MM-dd'}}</span> should display the current date.
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How to get the command line args passed to a running process on unix/linux systems?
On SunOS there is pargs command that prints the command line arguments passed to the running process.
13 Answers
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How do I get the web page contents from a WebView?
On Android, I have a WebView that is displaying a page.
7 Answers
7
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When should I use ugettext_lazy?
I have a question about using ugettext and ugettext_lazy for translations.
I learned that in models I should use ugettext_lazy , while in views ugettext.
But are there any other places, where I should use ugettext_lazy too? What about form definitions?
Are there any performance diffrences betwe...
What's better to use in PHP, $array[] = $value or array_push($array, $value)?
...
No benchmarks, but I personally feel like $array[] is cleaner to look at, and honestly splitting hairs over milliseconds is pretty irrelevant unless you plan on appending hundreds of thousands of strings to your array.
Edit: Ran this code:
$t = microtime(true);
$array = array();
for($i = 0; $i <...
Cannot use a CONTAINS or FREETEXT predicate on table or indexed view because it is not full-text ind
...e explicitly if there is no default full-text catalog.
You can do step 2 and 3 in SQL Sever Management Studio. In object explorer, right click on a table, select Full-Text index menu item and then Define Full-Text Index... sub-menu item. Full-Text indexing wizard will guide you through the process...
Can you use reflection to find the name of the currently executing method?
... when using release mode when compiling, there might be some optimizations and the stack may not be what you expect.
– Axel O'Connell
May 27 '15 at 11:03
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How to make Regular expression into non-greedy?
...'m using jQuery. I have a string with a block of special characters (begin and end). I want get the text from that special characters block. I used a regular expression object for in-string finding. But how can I tell jQuery to find multiple results when have two special character or more?
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