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What does .SD stand for in data.table in R
...,3), v=1:6)
setkey(DT, y)
DT
# x y v
# 1: a 1 1
# 2: b 1 3
# 3: c 1 5
# 4: a 3 2
# 5: b 3 4
# 6: c 3 6
Doing this may help you see what .SD is:
DT[ , .SD[ , paste(x, v, sep="", collapse="_")], by=y]
# y V1
# 1: 1 a1_b3_c5
# 2: 3 a2_b4_c6
Basically, the by=y statement breaks the orig...
Accessing members of items in a JSONArray with Java
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idewz
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notnoopnotnoop
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Tying in to Django Admin's Model History
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Van GaleVan Gale
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Why do Twitter Bootstrap tables always have 100% width?
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edited Feb 11 '15 at 13:42
Iulian Onofrei
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Why does GCC generate such radically different assembly for nearly the same C code?
...iting an optimized ftol function I found some very odd behaviour in GCC 4.6.1 . Let me show you the code first (for clarity I marked the differences):
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Correct way to delete cookies server-side
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Dave Jarvis
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answered Mar 12 '11 at 22:38
LekensteynLekens...
What does the keyword Set actually do in VBA?
...ference to an object. The C equivalent would be
int i;
int* ref_i;
i = 4; // Assigning a value (in VBA: i = 4)
ref_i = &i; //assigning a reference (in VBA: set ref_i = i)
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How to explain Katana and OWIN in simple words and uses?
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