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Assign multiple columns using := in data.table, by group
What is the best way to assign to multiple columns using data.table ? For example:
2 Answers
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Detecting iOS / Android Operating system
I've done some research, and this question has come up, but not in the way I intend. I'm building a page for a client that is a QR code landing, which is a place to download an application. So he doesn't have to print out 2 QR codes on a page, I'd like to detect the current operating system (Apple...
DESTDIR and PREFIX of make
I am trying to make software install to a specific directory. I found several ways, but not sure what are the differences between them.
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What is the difference between related SQLite data-types like INT, INTEGER, SMALLINT and TINYINT?
When creating a table in SQLite3, I get confused when confronted with all the possible datatypes which imply similar contents, so could anyone tell me the difference between the following data-types?
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Counting Chars in EditText Changed Listener
In my project I have an EditText . I want to count the characters in the EditText , and show that number it in a TextView . I have written the following code and it works fine. However, my problem is when I click Backspace it counts up, but I need to decrement the number. How can I consider Ba...
Is there an equivalent to 'continue' in a Parallel.ForEach?
I am porting some code to Parallel.ForEach and got an error with a continue I have in the code. Is there something equivalent I can use in a Parallel.ForEach functionally equivalent to continue in a foreach loop?
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Convert data.frame column format from character to factor
I would like to change the format (class) of some columns of my data.frame object ( mydf ) from charactor to factor .
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How to verify a user's password in Devise
I'm having a problem matching user password using devise gem in rails. User password stored on my db which is encrypted_password and i am trying to find user by password, but I don't understand how to match password from form and encrypted_password in my db.
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Sourcetree - undo unpushed commits
I am using Sourcetree for Windows for a git-repository and would like to undo an unpushed commit.
4 Answers
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Oracle SELECT TOP 10 records
I have an big problem with an SQL Statement in Oracle. I want to select the TOP 10 Records ordered by STORAGE_DB which aren't in a list from an other select statement.
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