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What does .SD stand for in data.table in R
... .SDcols to batch-convert groups of such columns.
We notice that the following columns are stored as character in the Teams data set:
# see ?Teams for explanation; these are various IDs
# used to identify the multitude of teams from
# across the long history of baseball
fkt = c('teamIDBR', 'te...
How to make/get a multi size .ico file? [closed]
...d the following layers sized correctly.
256x256 will be saved as 32bpp 8bit alpha
48x48 will be saved as 32bpp 8bit alpha
48x48 will be saved as 8bpp 1bit alpha
32x32 will be saved as 32bpp 8bit alpha
32x32 will be saved as 8bpp 1bit alpha
32x32 will be saved as 4bpp 1bit alpha
16x16 will be...
biggest integer that can be stored in a double
... DBL_MAX or approximately 1.8 × 10308 (if your double is an IEEE 754 64-bit double). It's an integer. It's represented exactly. What more do you want?
Go on, ask me what the largest integer is, such that it and all smaller integers can be stored in IEEE 64-bit doubles without losing precision. A...
How to do what head, tail, more, less, sed do in Powershell? [closed]
On windows, using Powershell, what are the equivalent commands to linux's head , tail , more , less and sed ?
7 Answe...
Usage of __slots__?
...y 16 bytes, and 56 total bytes with one item in slots, 64 with two.
For 64 bit Python, I illustrate the memory consumption in bytes in Python 2.7 and 3.6, for __slots__ and __dict__ (no slots defined) for each point where the dict grows in 3.6 (except for 0, 1, and 2 attributes):
Python 2.7 ...
Print number of keys in Redis
...b63575307aaffe0a
redis_mode:standalone
os:Linux 5.4.0-1017-aws x86_64
arch_bits:64
multiplexing_api:epoll
atomicvar_api:atomic-builtin
gcc_version:9.3.0
process_id:2854672
run_id:90a5246f10e0aeb6b02cc2765b485d841ffc924e
tcp_port:6379
uptime_in_seconds:2593097
uptime_in_days:30
hz:10
configured_hz:10...
iOS: how to perform a HTTP POST request?
...
I thought I would update this post a bit and say that alot of the iOS community has moved over to AFNetworking after ASIHTTPRequest was abandoned. I highly recommend it. It's a great wrapper around NSURLConnection and allows for asynchronous calls, and basically...
What are the advantages of NumPy over regular Python lists?
...definitely would for a billion cells -- neither approach would fit in a 32-bit architecture, but with 64-bit builds NumPy would get away with 4 GB or so, Python alone would need at least about 12 GB (lots of pointers which double in size) -- a much costlier piece of hardware!
The difference is most...
coinitialize失败，返回值是0x80010106 无法在设置线程模式后对其加以更改 ...
...THREADED);
问题得以解决。
CoInitialize、CoInitializeEx都是windows的API，主要是告诉windows以什么方式为程序创建COM对象，原因是程序调用com库函数（除CoGetMalloc和内存分配函数）之前必须初始化com库。
有哪些方式呢？单线程和多...
What optimizations can GHC be expected to perform reliably?
...y the same, not the same by value. For example, CSE won't fire in the following code without a bunch of inlining:
x = (1 + (2 + 3)) + ((1 + 2) + 3)
y = f x
z = g (f x) y
However, if you compile via llvm, you may get some of this combined, due to its Global Value Numbering pass.
Liberate case
Thi...