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How do I delete rows in a data frame?
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The key idea is you form a set of the rows you want to remove, and keep the complement of that set.
In R, the complement of a set is given by the '-' operator.
So, assuming the data.frame is called myData:
myData[-c(2, 4, 6), ] # notice the -
Of course, don't forget to "reassign" ...
How to generate and validate a software license key?
...eveloping a product (developed in C#) that'll be available for downloading and installing for free but in a very limited version. To get access to all the features the user has to pay a license fee and receive a key. That key will then be entered into the application to "unlock" the full version.
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In Java, how do I convert a byte array to a string of hex digits while keeping leading zeros? [dupli
...oach would be to check how many digits are output by Integer.toHexString() and add a leading zero to each byte if needed. Something like this:
public static String toHexString(byte[] bytes) {
StringBuilder hexString = new StringBuilder();
for (int i = 0; i < bytes.length; i++) {
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Given a class, see if instance has method (Ruby)
...don't know why everyone is suggesting you should be using instance_methods and include? when method_defined? does the job.
class Test
def hello; end
end
Test.method_defined? :hello #=> true
NOTE
In case you are coming to Ruby from another OO language OR you think that method_defined means ...
rsync: difference between --size-only and --ignore-times
I'm trying to understand what the difference is between two options
4 Answers
4
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How do I solve the INSTALL_FAILED_DEXOPT error?
I am developing an Android application using Android 2.2, my application APK size is 22.5 MB, and I would like to create a new build for a Samsung tablet. I got the following error:
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Convert command line arguments into an array in Bash
How do I convert command-line arguments into a bash script array?
7 Answers
7
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Hook up Raspberry Pi via Ethernet to laptop without router? [closed]
...ially recover the Raspberry Pi, it will most likely be in a rural location and I'd like to turn off the Pi at that point safely.
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How to enumerate an enum with String type?
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print($0.rawValue)
}
Compatibility with earlier Swift versions (3.x and 4.x)
If you need to support Swift 3.x or 4.0, you may mimic the Swift 4.2 implementation by adding the following code:
#if !swift(>=4.2)
public protocol CaseIterable {
associatedtype AllCases: Collection where AllC...
Use rvmrc or ruby-version file to set a project gemset with RVM?
I use RVM, the Ruby Version Manager to specify a Ruby version and a set of gems for each of my Rails projects.
5 Answers
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