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Numbering rows within groups in a data frame
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Use ave, ddply, dplyr or data.table:
df$num <- ave(df$val, df$cat, FUN = seq_along)
or:
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LINQ: “contains” and a Lambda query
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Malice
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answered Oct 14 '09 at 14:06
Rex MRex M
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Is there a quicker / better way to clear the iPhone Simulator cache than deleting its directory?
... simctl erase all
Safe and effective.
See https://stackoverflow.com/a/26394597/218152 for single device
xcrun simctl erase [device ID]
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How to remove jar file from local maven repository which was added with install:install-file?
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edited Sep 3 at 11:45
shareef
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How does the C# compiler detect COM types?
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__FILE__, __LINE__, and __FUNCTION__ usage in C++
... Evan TeranEvan Teran
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What does pylint's “Too few public methods” message mean
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How to generate random SHA1 hash to use as ID in node.js?
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Scrollable Menu with Bootstrap - Menu expanding its container when it should not
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Working example: https://www.bootply.com/86116
Bootstrap 4
Another example for Bootstrap 4 using flexbox
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Do declared properties require a corresponding instance variable?
...sing the Modern Objective-C Runtime (that's either iOS 3.x or greater, or 64-bit Snow Leopard or greater) then you do not need to define ivars for your properties in cases like this.
When you @synthesize the property, the ivar will in effect be synthesized also for you. This gets around the "fragil...