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Purpose of Unions in C and C++
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Erich KitzmuellerErich Kitzmueller
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Convert data.frame column format from character to factor
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Sam FirkeSam Firke
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How can I read and parse CSV files in C++?
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stefanBstefanB
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Good ways to manage a changelog using git?
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Harshniket SetaHarshniket Seta
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Golang: How to pad a number with zeros when printing?
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InductionInduction
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Maven: The packaging for this project did not assign a file to the build artifact
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A_Di-MatteoA_Di-Matteo
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How to read and write INI file with Python3?
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Rik PoggiRik Poggi
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Creation timestamp and last update timestamp with Hibernate and MySQL
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Baldrick
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answered Oct 21 '08 at 13:14
Guðmundur BjarniGuð...
Mean per group in a data.frame [duplicate]
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1 Aira 16.33333 47.00000
2 Ben 31.33333 50.33333
3 Cat 44.66667 54.00000
Here we aggregate columns 3 and 4 of data.frame d, grouping by d$Name, and applying the mean function.
Or, using a formula interface:
aggregate(. ~ Name, d[-2], mean)
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Finding the number of days between two dates
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duplode
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answered Mar 24 '14 at 9:55
Aditya P BhattAditya...