大约有 43,100 项符合查询结果（耗时：0.0446秒） [XML]
Validating IPv4 addresses with regexp
...uch luck. It seemed at one point I had had it with (25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?(\.|$)){4} , but it produces some strange results:
...
Split a vector into chunks in R
... is seq_along(), split() and ceiling():
> d <- rpois(73,5)
> d
[1] 3 1 11 4 1 2 3 2 4 10 10 2 7 4 6 6 2 1 1 2 3 8 3 10 7 4
[27] 3 4 4 1 1 7 2 4 6 0 5 7 4 6 8 4 7 12 4 6 8 4 2 7 6 5
[53] 4 5 4 5 5 8 7 7 7 6 2 4 3 3 8 11 6 6 1...
How to add an extra column to a NumPy array
...
16 Answers
16
Active
...
Difference between numpy.array shape (R, 1) and (R,)
In numpy , some of the operations return in shape (R, 1) but some return (R,) . This will make matrix multiplication more tedious since explicit reshape is required. For example, given a matrix M , if we want to do numpy.dot(M[:,0], numpy.ones((1, R))) where R is the number of rows (of co...
Context switches much slower in new linux kernels
We are looking to upgrade the OS on our servers from Ubuntu 10.04 LTS to Ubuntu 12.04 LTS. Unfortunately, it seems that the latency to run a thread that has become runnable has significantly increased from the 2.6 kernel to the 3.2 kernel. In fact the latency numbers we are getting are hard to belie...
Automatically expanding an R factor into a collection of 1/0 indicator variables for every factor le
...level, there is an associated column in a new data frame, which contains a 1/0 indicator. E.g., suppose I have:
8 Answers
...
搭建高可用mongodb集群（二）—— 副本集 - 大数据 & AI - 清泛网 - 专注C/...
...机器数量为至少3个，那我们也按照这个数量配置测试。
1、准备两台机器 192.168.1.136、192.168.1.137、192.168.1.138。 192.168.1.136 当作副本集主节点，192.168.1.137、192.168.1.138作为副本集副本节点。
2、分别在每台机器上建立mongodb副本集...
What is the easiest way to remove the first character from a string?
...
15 Answers
15
Active
...