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In C# check that filename is *possibly* valid (not that it exists) [duplicate]
... edited Apr 30 '17 at 0:51
buræquete
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answered Jan 7 '09 at 21:11
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Numpy: find first index of value fast
...e(100000)
%timeit index(arr, 5) # 1000000 loops, best of 3: 1.88 µs per loop
%timeit find_first(5, arr) # 1000000 loops, best of 3: 1.7 µs per loop
%timeit index(arr, 99999) # 10000 loops, best of 3: 118 µs per loop
%timeit find_first(99999, arr) # 10000 loops, best of 3: 9...
Is there a way to make R beep/play a sound at the end of a script?
...ered Jul 1 '14 at 18:08
Rasmus BååthRasmus Bååth
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Remove rows with duplicate indices (Pandas DataFrame and TimeSeries)
...>> %timeit df3.groupby(df3.index).first()
1000 loops, best of 3: 580 µs per loop
>>> %timeit df3[~df3.index.duplicated(keep='first')]
1000 loops, best of 3: 307 µs per loop
Note that you can keep the last element by changing the keep argument to 'last'.
It should also be noted tha...
Approximate cost to access various caches and main memory?
... Mutex lock/unlock
100 ns Main memory (RAM)
2 000 ns (2µs) 1KB Zippy-compress
Still some improvements, prediction for 2020
16 000 ns (16µs) SSD random read (olibre's note: should be less)
500 000 ns (½ms) Round trip in datacenter
2 000 000 ns (2ms) HDD random read (s...
What is your preferred style for naming variables in R? [closed]
...ered Nov 16 '12 at 8:55
Rasmus BååthRasmus Bååth
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What's the difference between UTF-8 and UTF-8 without BOM?
...nded but it did wonders to my powershell script when trying to output "æøå"
– Marius
Nov 12 '13 at 9:22
63
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MongoDB副本集详解 优于以往的主从模式 - 大数据 & AI - 清泛网 - 专注C/C++及内核技术
...间延迟从primary节点同步数据。主要用于备份数据，如果实时同步，误删除数据马上同步到从节点。所以延迟复制主要用于避免用户错误。
Non-Voting：没有选举权的secondary节点，纯粹的备份数据节点。
6 设置隐藏节点(Hidden)
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淘宝大秒系统设计详解 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...数据库层保证数据最终准确性，如库存不能减为负数。
实时热点发现
其实秒杀系统本质是还是一个数据读的热点问题，而且是最简单一种，因为在文提到通过业务隔离，我们已能提前识别出这些热点数据，我们可以提前做一...
AppInventor2 文本输入框（TextBox）已支持文本变更事件，非常便于实时处理...
自 v2.70开始，文本输入框加入了文本变更事件：
效果如下：
同理，密码输入框组件也是一样的。