大约有 40,000 项符合查询结果（耗时：0.0365秒） [XML]
Repeat each row of data.frame the number of times specified in a column
...es
library(dplyr)
df %>%
slice(rep(seq_len(n()), freq)) %>%
select(-freq)
# var1 var2
#1 a d
#2 b e
#3 b e
#4 c f
#5 c f
#6 c f
seq_len(n()) part can be replaced with any of the following.
df %>% slice(rep(1:nrow(df), freq)) %>% select(-...
How to downgrade or install an older version of Cocoapods
...e default version, so you have to sudo gem uninstall cocoapods first, then select 1.0.0 as the version to remove. Not sure if this has always been the behavior, but sudo gem install cocoapods -v 0.39.0 alone didn't do the trick for me once I had 1.0.0.
– fullofsquirrels
...
Count immediate child div elements using jQuery
...est to see the speed difference and the children() method beaten the child selector (#foo > div) approach by at least 60% in Chrome (canary build v15) 20-30% in Firefox (v4).
By the way, needless to say, these two approaches produce same results (in this case, 1000).
[Update] I've updated the t...
Multiline strings in VB.NET
...
I used this variant:
Dim query As String = <![CDATA[
SELECT
a.QuestionID
FROM
CR_Answers a
INNER JOIN
CR_Class c ON c.ClassID = a.ClassID
INNER JOIN
CR_Questions q ON q.QuestionID = a.QuestionID
...
How to delete an item in a list if it exists?
... new_tag from a form text field with self.response.get("new_tag") and selected_tags from checkbox fields with
7 Answ...
How to move columns in a MySQL table?
...min provides a GUI for this within the structure view of a table.
Check to select the column you want to move and click the change action at the bottom of the column list.
You can then change all of the column properties and you'll find the 'move column' function at the far right of the screen.
Of ...
How can I delete all unversioned/ignored files/folders in my working copy?
...ovides a finer grain resolution than Stefan's answer provided, letting you select non-versioned files separately from ignored files. Just select TortoiseSvn >> Clean up... to open this dialog.
share
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Should I commit or rollback a read transaction?
... I create a temp table, populate it with ids, join it with a data table to select the data that goes with the ids, then delete the temp table. I'm really just reading data, and I don't care what happens to the temp table, since it's temporary... but from a performance perspective, would it be more ...
Using Caps Lock as Esc in Mac OS X
...d fixing bugs.
Here's a screenshot to show a few of the (hundreds of) pre-selectable options:
PQRS also has a great utility called NoEjectDelay that you can use in combination with KeyRemap4MacBook for reprogramming the Eject key. After a little tweaking I have mine set to toggle the AirPort Wif...
How to make git-diff and git log ignore new and deleted files?
...
Offical document:
--diff-filter=[(A|C|D|M|R|T|U|X|B)…[*]]
Select only files that are Added (A), Copied (C), Deleted (D), Modified (M), Renamed (R), have their type (i.e. regular file, symlink, submodule, …) changed (T), are Unmerged (U), are Unknown (X), or have had their pairi...