大约有 13,000 项符合查询结果（耗时：0.0328秒） [XML]
Aggregate / summarize multiple variables per group (e.g. sum, mean)
...-date), sum)
# summarising a specific set of non-grouping variables using select_helpers
# see ?select_helpers for more options
df2 <- df1 %>% group_by(year, month) %>% summarise_at(vars(starts_with('x')), sum)
df2 <- df1 %>% group_by(year, month) %>% summarise_at(vars(matches('.*...
Fancybox doesn't work with jQuery v1.9.0 [ f.browser is undefined / Cannot read property 'msie' ]
...' + ($.browser.msie ? 'allowtransparency="true""' : '') + ' scrolling="' + selectedOpts.scrolling + '" src="' + currentOpts.href + '"></iframe>').appendTo(content);
+ $('<iframe id="fancybox-frame" name="fancybox-frame' + new Date().getTime() + '" frameborder="0" hspace="0"...
What is the intended use-case for git stash?
...n reason for this is that git stash push introduces the option of stashing selected pathspecs, something git stash save does not support.
– Krishna Gupta
Jul 6 at 2:19
...
Changing the case of a string in Eclipse
How do I make a lowercase string uppercase using Eclipse? I want to select a string and either uppercase it or lowercase it. Is there a shortcut for doing this?
...
ZSH iterm2 increase number of lines history
...2 documentation on how to change it.
open the iTerm2 preferences ⌘ + ,
select the Profiles tab
then select the Terminal subtab
Beware, changes to the Scrollback lines value take effect immediately so check Unlimited scrollback now if you don't want to delete your current buffer(s)
change the val...
Is there a way to create multiline comments in Python?
...
In any case, your text editor should also be able to easily comment-out a selected region (by placing a # in front of each line individually). If not, switch to a text editor that does.
Programming in Python without certain text editing features can be a painful experience. Finding the right edito...
UIScrollView Scrollable Content Size Ambiguity
...o this view. Don't forget to set the bottom constraint on the lowest view.
Select the UIScrollView, select the size inspector and deselect Content Layout Guides.
share
|
improve this answer
...
How do I run multiple instances of Android Studio
...ultiple instances of Android Studio? A second instance is launched if you select "File\New Project", but "File\Open" and "File\Reopen" does not create a second instance.
...
LINQ Orderby Descending Query
...(x=>x.Delivery)
where !t.Items && t.DeliverySelection
orderby t.Delivery.SubmissionDate descending
select t;
share
|
improve t...
How to view revision history for Mercurial file?
...a while to figure out how. You need to right-click on the desired file and select "File History". However, for some mysterious reason, the file needs to be unaltered. Furthermore, to find the desired file there are two options:
In ### revision set query### one can type:
file("**<myfile>")
...