大约有 23,000 项符合查询结果（耗时：0.0481秒） [XML]
Is R's apply family more than syntactic sugar?
...an be substantial, like when you have to nest for-loops to get the average based on a grouping of more than one factor. Here you have two approaches that give you the exact same result :
set.seed(1) #for reproducability of the results
# The data
X <- rnorm(100000)
Y <- as.factor(sample(lett...
Stop form refreshing page on submit
...rs, on IE (v 11.0.9600.18426), FF (v 40.03) & Chrome (v 53.02785.143 m 64 bit)
The source code HTML & js are in the snippet. The principle is described there.
Warning:
You can't test it in the snippet because the post action is not
defined and hitting Enter key might interfer with sta...
HTML img tag: title attribute vs. alt attribute?
...
64
I'd go for both. Title will show a nice tooltip in all browsers and alt will give a descriptio...
Sublime Text 2 keyboard shortcut to open file in specified browser (e.g. Chrome)
...PackageSettings--> view in Browser -- > default settings; to "chrome 64" ( was "firefox"). Then works perfectly with any shortcut ;)
– kolboc
Jul 8 '16 at 12:20
add a co...
What is considered a good response time for a dynamic, personalized web application? [closed]
...
164
There's a great deal of research on this. Here's a quick summary.
Response Times: The 3 Imp...
Can someone explain the dollar sign in Javascript?
...
cobbalcobbal
64.5k1616 gold badges133133 silver badges154154 bronze badges
...
MySQL: Enable LOAD DATA LOCAL INFILE
...e on 8.0.12 MySQL Community Server on Windows.
– endo64
Nov 20 '18 at 13:50
I have MySQL 8.0.16 installed on Windows s...
Python list of dictionaries search
...a/quQzv (method names see below).
All tests done with Python 3.6.4, W7x64.
from random import randint
from timeit import timeit
list_dicts = []
for _ in range(1000): # number of dicts in the list
dict_tmp = {}
for i in range(10): # number of keys for each dict
dict_tmp[f...
Most efficient T-SQL way to pad a varchar on the left to a certain length?
... not very efficient in terms of execution time. The Tally table I used has 64,000 records. Kudos to Martin Smith for pointing out execution time efficiency.
SET STATISTICS TIME ON
select FORMAT(N, 'd10') as padWithZeros from Tally
SET STATISTICS TIME OFF
SQL Server Execution Times:
CPU time =...
Crash logs generated by iPhone Simulator?
.../MyApp
set print asm-demangle on
set print symbol-filename on
p/a 0×00015c64 -> address got by opening the crash log in “Console” app or just double clicking the the .crash file.
share
|
im...