大约有 40,000 项符合查询结果（耗时：0.0495秒） [XML]
How can I create a correlation matrix in R?
...
An example,
d &lt- data.frame(x1=rnorm(10),
x2=rnorm(10),
x3=rnorm(10))
cor(d) # get correlations (returns matrix)
share
...
Unix's 'ls' sort by name
...
My ls sorts by name by default. What are you seeing?
man ls states:
List information about the FILEs (the current directory by default). Sort entries alpha‐betically if none of -cftuvSUX nor --sort is specified.:
...
How to revert a “git rm -r .”?
...p://www.spinics.net/lists/git/msg62499.html
git prune -n
git cat-file -p <blob #>
share
|
improve this answer
|
follow
|
...
Can I use GDB to debug a running process?
...y the program, and to load its symbol table.
NOTE: You may have difficulty attaching to a process due to improved security in the Linux kernel - for example attaching to the child of one shell from another.
You'll likely need to set /proc/sys/kernel/yama/ptrace_scope depending on your requireme...
Django - limiting query results
...s a query will hit the database only when you specifically ask for the result.
So until you print or actually use the result of a query you can filter further with no database access.
As you can see below your code only executes one sql query to fetch only the last 10 items.
In [19]: import logg...
Error Dropping Database (Can't rmdir '.test\', errno: 17)
... the windows command editor. Now, the next process was to display the default databases (info. schema, mysql and test) which was achieved by using "SHOW DATABASES;"
...
How do I flag a method as deprecated in Objective-C 2.0?
...large iPad app and there are many different classes we've created as a result. The trouble is some of the methods are now pretty much obsolete and I don't want simply remove them yet as I know some parts of the overall system use the methods... but there are better (newer) variants available which ...
Spring get current ApplicationContext
...
context = ac;
}
}
Add an entry in application-context.xml
<bean id="applicationContextProvider"
class="com.java2novice.spring.ApplicationContextProvider"/>
In annotations case (instead of application-context.xml)
@Component
public class ApplicationCon...
Use of 'const' for function parameters
...ence and pointer parameters. For copied objects it doesn't really matter, although it can be safer as it signals intent within the function. It's really a judgement call. I do tend to use const_iterator though when looping on something and I don't intend on modifying it, so I guess to each his own, ...
iOS 7 - Failing to instantiate default view controller
... create it I go for the run button e click on it, then the project gets built but it does not show in the iOS Simulator and I get the following message:
...