大约有 48,000 项符合查询结果（耗时：0.0473秒） [XML]
Remove an entire column from a data.frame in R
...on't need drop argument cause it always return data.frame from data.frame. And I think this is much better way to localized columns (and only columns) in data.frame (and it's faster). Check: cars[-1] (one col data.frame) or better cars[-(1:2)]: data frame with 0 columns and 50 rows.
...
iPad/iPhone hover problem causes the user to double click a link
...sites I built times ago, that use jquery mouse events...I just got an ipad and i noticed that all the mouse over events are translated in clicks...so for instance i have to do two clicks instead of one..(the first hover, than the actual click)
...
Best way to select random rows PostgreSQL
I want a random selection of rows in PostgreSQL, I tried this:
12 Answers
12
...
How can I correctly prefix a word with “a” and “an”?
...
Download Wikipedia
Unzip it and write a quick filter program that spits out only article text (the download is generally in XML format, along with non-article metadata too).
Find all instances of a(n).... and make an index on the following word and all ...
Remove rows with all or some NAs (missing values) in data.frame
... 1 2 3 2
but using complete.cases is quite a lot more clear, and faster.
share
|
improve this answer
|
follow
|
...
What are the advantages of using a schema-free database like MongoDB compared to a relational databa
I'm used to using relational databases like MySQL or PostgreSQL, and combined with MVC frameworks such as Symfony, RoR or Django, and I think it works great.
...
Defeating a Poker Bot
...e triggered by
suspicious activity.
Some poker sites monitor playing
times and patterns (i.e., worst case
scenario is a player who plays 24x7
and 16 tables continuously, there is
a tiny tiny chance this is a real
human. (However some players do have the ability to play very large hand volumes which ...
Can I run javascript before the whole page is loaded?
...er encounters a classic script tag when parsing the HTML, it stops parsing and hands over to the JavaScript interpreter, which runs the script. The parser doesn't continue until the script execution is complete (because the script might do document.write calls to output markup that the parser should...
What is the difference between tree depth and height?
...
The difference between them is that in one case you count number of nodes and in other number of edges on the shortest path between root and concrete node.
Which is which?
...
Remove multiple whitespaces
I'm getting $row['message'] from a MySQL database and I need to remove all whitespace like \n \t and so on.
15 Answer...