大约有 43,500 项符合查询结果（耗时：0.0397秒） [XML]
Maven: missing net.sf.json-lib
...-lib in the central repository . Copy-pasted the dependency (with version 2.3), and then when I build I get this error:
4 ...
Should I use a data.frame or a matrix?
...e the choice.
Also:
Matrices are more memory efficient:
m = matrix(1:4, 2, 2)
d = as.data.frame(m)
object.size(m)
# 216 bytes
object.size(d)
# 792 bytes
Matrices are a necessity if you plan to do any linear algebra-type of operations.
Data frames are more convenient if you frequently refer to ...
How to get the second column from command output?
...
29
Or use sed & regex.
<some_command> | sed 's/^.* \(".*"$\)/\1/'
...
How to subtract 2 hours from user's local time?
...e JavaScript code block that will allow me to display the local time minus 2 hours?
2 Answers
...
ArithmeticException: “Non-terminating decimal expansion; no exact representable decimal result”
...
862
From the Java 11 BigDecimal docs:
When a MathContext object is supplied with a precision settin...
Pairwise crossproduct in Python [duplicate]
...
You're looking for itertools.product if you're on (at least) Python 2.6.
>>> import itertools
>>> a=[1,2,3]
>>> b=[4,5,6]
>>> itertools.product(a,b)
<itertools.product object at 0x10049b870>
>>> list(itertools.product(a,b))
[(1, 4), (1, 5), ...
C# '@' before a String [duplicate]
...
answered Feb 2 '11 at 19:54
Mark AveniusMark Avenius
12.6k66 gold badges3636 silver badges4848 bronze badges
...
当当网第三季度净亏损2810万元 同比由盈转亏 - 资讯 - 清泛网 - 专注C/C++及内核技术
当当网第三季度净亏损2810万元 同比由盈转亏11月25日消息，当当网发布了截至2015年9月30日的2015财年第三季度未审计财报。财报显示，当当网第三季度总净营收为23.719亿元人民币(约合3.732亿美元)，同比增长22.6%；净亏损为2810万元...
CentOS系统下如何挂载第2块磁盘 - 更多技术 - 清泛网 - 专注C/C++及内核技术
CentOS系统下如何挂载第2块磁盘1、查看新硬盘 # fdisk -l新添加的硬盘的编号为 dev sdb 2、硬盘分区 1）进入fdisk模式 # fdisk dev sdb2）输入n进行分区...1、查看新硬盘
# fdisk -l
新添加的硬盘的编号为/dev/sdb
2、硬盘分区
...