大约有 1,200 项符合查询结果（耗时：0.0367秒） [XML]
Useful GCC flags for C
...******
mudflap violation 1 (check/write): time=1280862302.170759 ptr=0x7fff96eb3d00 size=44
pc=0x7f3a575503c1 location=`mf.c:4:2 (main)'
/usr/lib/libmudflap.so.0(__mf_check+0x41) [0x7f3a575503c1]
./a.out(main+0x90) [0x400a54]
/lib/libc.so.6(__libc_start_main+0xfd) [0x7f3a571e2c4d]
...
Force R not to use exponential notation (e.g. e+10)?
...
format(1e6, scientific=FALSE) returns "1000000" while as.character(1e6) returns "1e+06", so there is a difference between the two methods.
– mickey
Dec 4 '18 at 18:24
...
Unicode equivalents for \w and \b in Java regular expressions?
...b is Unicode‐savvy. It makes tons and tons of mistakes. "\u2163=", "\u24e7=", and "\u0301=" all fail to matched pattern "\\b=" in Java, but are supposed to — as perl -le 'print /\b=/ || 0 for "\x{2163}=", "\x{24e7}=", "\x{301}="' reveals. However, if (and only if) you swap in my version of a w...
Is there a simple way to delete a list element by value?
...y, numpy data in Cython. [@Gill's answer is O(n*n) unnecessarily (compare 1e6 and 1e12 – you don't want to risk the latter). while 1: L.remove(value) and return on ValueError might work well with a few values or small lists in CPython.
– jfs
Aug 23 '14 at 2:...
Hook up Raspberry Pi via Ethernet to laptop without router? [closed]
...55
Use this address to find out the IP address of your RPi, it's 10.42.0.96 in my case because 10.42.0.1 is my laptop
$nmap -n -sP 10.42.0.255/24
Starting Nmap 6.40 ( http://nmap.org ) at 2016-02-20 23:07 CET
Nmap scan report for 10.42.0.1
Host is up (0.00031s latency).
Nmap scan repor...
ERROR 1396 (HY000): Operation CREATE USER failed for 'jack'@'localhost'
...k)
CREATE USER 'jack'@'localhost' IDENTIFIED BY PASSWORD '*Fi47ytFF3CD5B14E7EjkjkkC1D3F8086A5C0-krn';
(Get out of this situation by running DROP USER)
DROP USER 'jack'@'localhost';
(I suppose FLUSH PRIVILEGES can't hurt, but definitely drop the user first.)
...
What is the difference between $(command) and `command` in shell programming?
...
July 2014: The commit f25f5e6 (by Elia Pinto (devzero2000), April 2014, Git 2.0) adds to the nesting issue:
The backquoted form is the traditional method for command substitution, and is supported by POSIX.
However, all but the simplest uses beco...
Postgresql - change the size of a varchar column to lower length
...ay
http://www.postgresql.org/message-id/162867790801110710g3c686010qcdd852e721e7a559@mail.gmail.com
CREATE TABLE foog(a varchar(10));
ALTER TABLE foog ALTER COLUMN a TYPE varchar(30);
postgres=# \d foog
Table "public.foog"
Column | Type | Modifiers
--------+------------------...
How to concatenate properties from multiple JavaScript objects
...
This is one of the best I could say. Since E6 is now mostly used, Object.assign is the best answer.
– Vimalraj Selvam
Nov 22 '16 at 10:53
6
...
Append value to empty vector in R?
...cient way to append is to use index. Note that this time I let it iterate 1e7 times, but it's still much faster than c.
a=numeric(0)
system.time(
{
while(length(a)<1e7){
a[length(a)+1]=pi
}
}
)
# user system elapsed
# 5.71 0.39 6.12
This is acceptable. And we can ma...