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Mean per group in a data.frame [duplicate]
..."Rate2"), row.names = c(NA, -9L), class = c("data.table", "data.frame"))
Now to take the mean of Rate1 and Rate2 for all 3 months, for each person (Name):
First, decide which columns you want to take the mean of
colstoavg <- names(mydt)[3:4]
Now we use lapply to take the mean over the column...
C# vs C - Big performance difference
...employ some expert level optimization. 99% of programmers don't have the knowledge to use such optimization techniques just to get their code to run slightly faster than the c# code. Use cases for for c/c++ are narrowing.
– user2074102
Aug 23 '16 at 16:11
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Javascript web app and Java server, build all in Maven or use Grunt for web app?
...gest problem with both of these is that they are mostly Rhino based (WRO4J now has some Node support) and Rhino is dog slow compared to Node based tools. You also have to consider that the JavaScript tooling is rapidly maturing so you should be looking for tools that can move quickly.
WRO4J - Supp...
How do I modify fields inside the new PostgreSQL JSON datatype?
...LANGUAGE sql IMMUTABLE STRICT
COST 100;
Update: functions are compacted now.
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Does functional programming replace GoF design patterns?
...n patterns
found available to every other OOP
language. In fact, right now I use F#
and OCaml everyday, and there are no
striking differences between the
patterns I use in these languages vs
the patterns I use when I write in
Java.
Perhaps because you're still thinking imperatively? ...
Is there a pattern for initializing objects created via a DI container
...my objects and I want to have some initialization parameters that are not known until run-time:
5 Answers
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Generate a heatmap in MatPlotLib using a scatter data set
...in plot; so do (AFAIK) all of the plotting libraries for R; still i don't know if this is the generally accepted term for plots of this type, though i suspect it's likely given that hexbin is short for hexagonal binning, which is describes the essential step in preparing the data for display.)
fr...
Why does Razor _layout.cshtml have a leading underscore in file name?
...ghtful answer. I was under the misapprehension that Razor was tied to MVC. Now I see the reason for the leading underscore is to prevent them from being served directly under ASP.NET Web Pages.
– richb
Jan 3 '11 at 1:53
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what is the difference between sendStickyBroadcast and sendBroadcast in Android
... @Kushal: "So what should be alternative for sticky broadcast now?" -- I cannot really answer that, as I do not know what your use case is. You might consider asking a new Stack Overflow question, where you describe your business requirement, explain how you were thinking of solving it ...
Centering the pagination in bootstrap
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I don't know when drive-by downvoting became cool, but your first answer works for me so have an upvote.
– David Harbage
Nov 27 '13 at 1:20
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