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Remove columns from dataframe where ALL values are NA
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160
Try this:
df <- df[,colSums(is.na(df))<nrow(df)]
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JavaScript: location.href to open in new window/tab?
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alexalex
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How can I scan barcodes on iOS?
...ial C++ port of the core library. The port is a little old, from circa the 0.9 release of the Java code, but should still work reasonably well.
If you need to scan other formats, like 1D formats, you could continue the port of the Java code within this project to C++.
EDIT: Barcodes and the iphone...
Java ArrayList how to add elements at the beginning
... beginning of the array (so it has the lowest index) and if the array has 10 elements adding a new results in deleting the oldest element (the one with the highest index).
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Tool to read and display Java .class versions
...s.java"
public class MyClass
SourceFile: "MyClass.java"
minor version: 0
major version: 46
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To only show the version:
WINDOWS> javap -verbose MyClass | find "version"
LINUX > javap -verbose MyClass | grep version
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How to use int.TryParse with nullable int? [duplicate]
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answered Aug 2 '10 at 18:44
Jon SkeetJon Skeet
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Determine if a function exists in bash
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answered Sep 17 '08 at 18:00
JBBJBB
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Check if a JavaScript string is a URL
...ted Feb 25 '19 at 15:23
3limin4t0r
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answered Apr 19 '11 at 13:29
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PHP 5.4 Call-time pass-by-reference - Easy fix available?
...lone are enough to correctly pass the argument by reference. As of PHP 5.3.0, you will get a warning saying that "call-time pass-by-reference" is deprecated when you use & in foo(&$a);.
For example, instead of using:
// Wrong way!
myFunc(&$arg); # Deprecated pass-by-refe...
In Python, how do I index a list with another list?
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answered Jun 18 '09 at 11:38
vanvan
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