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Replace all 0 values to NA
I have a dataframe with some numeric columns. Some row has a 0 value which should be considered as null in statistical analysis. What is the fastest way to replace all the 0 value to NULL in R?
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How to wait for all threads to finish, using ExecutorService?
I need to execute some amount of tasks 4 at a time, something like this:
26 Answers
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NSUserDefaults not cleared after app uninstall on simulator
this may sound real NOOB! I want to check if it's the second time the user enters my application, so to keep the run count I'm using NSUserDefaults . I have implemented the following code in my rootViewController 's viewDidLoad method:
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Do you have to restart apache to make re-write rules in the .htaccess take effect?
I have pushed my .htaccess files to the production severs, but they don't work. Would a restart be the next step, or should I check something else.
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AWS S3: how do I see how much disk space is using
I have AWS account. I'm using S3 to store backups from different servers. The question is there any information in the AWS console about how much disk space is in use in my S3 cloud?
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Identifying the dependency relationship for python packages installed with pip
When I do a pip freeze I see large number of Python packages that I didn't explicitly install, e.g.
8 Answers
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What are JavaScript's builtin strings?
this question is difficult to summarize in a question title
7 Answers
7
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How can I combine two HashMap objects containing the same types?
I have two HashMap objects defined like so:
16 Answers
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When would you use the different git merge strategies?
From the man page on git-merge, there are a number of merge strategies you can use.
4 Answers
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Undo a merge by pull request?
Someone accepted a pull request which they shouldn't have. Now we have a bunch of broken code merged in. How do you undo a pull request? I was just going to revert the changes to the commit just before the merge, but I noticed that it merged in a bunch of commits. So now there are all these commits ...