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Determine the number of NA values in a column
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Was too quick to ask. sum(df$col==value,na.rm=FALSE) does the trick.
– user3274289
Jun 4 '14 at 2:18
4
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Convert int to string?
... Are all these solutions equally efficient? I'd imagine i.ToString() does some unnecessary boxing of the int, but perhaps that is optimised anyway.
– Stephen Holt
Sep 23 '13 at 16:22
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How to convert date to timestamp?
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Unfortunately, this does not work in Safari5, as it returns NaN. In Safari you have to use the other possible constructor new Date(year, month, day);, regarding this example: new Date(myDate[2], myDate[1], myDate[0]);
– ins...
Use RSA private key to generate public key?
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@jaime, That's because it doesn't - genrsa only generates the private key, the public key doesn't get stored. However if you have the private key then you can calculate (derive) the public key from it - which is what the 2nd command above does. It cal...
Android studio, gradle and NDK
...ion". I understood it to mean "a way to use the NDK with gradle" which now does exist, albeit none of them are fantastic solutions. However, based on your comment, it seems your team has something else in mind for what a true integration could be. I retract my previous statement.
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Do rails rake tasks provide access to ActiveRecord models?
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what does this syntax mean? it's assigning new_task to the current environment? what is the current value of :environment? google is not helping.
– Scott Coates
Oct 18 '12 at 2:29
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How to use '-prune' option of 'find' in sh?
... it's not 100% obvious in your text (but as you only print '*.foo' it doesn't conflict) but the -prune part will also not print anything (not only directories) named ".snapshot". ie, -prune doesn't only work on directories (but, for directories, it also does prevent entering the directories mat...
Why sizeof int is wrong, while sizeof(int) is right?
...ond * is part of the type or an arithmetic operator.
The existing grammar does already resolve the potential ambiguity of sizeof (int *) + 1. It is (sizeof(int*))+1, not sizeof((int*)(+1)).
C++ has a somewhat similar issue to resolve with function-style cast syntax. You can write int(0) and you ca...
Switching from zsh to bash on OSX, and back again?
... How do you change the default? Also, when I do "exec bash" in zsh, it does not source my bash_profile.
– kalehv
Jan 11 '14 at 17:59
1
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How to set downloading file name in ASP.NET Web API
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You have another answer to downloading a file here. Does it matter whether you use System.Net.Mime.ContentDisposition or ContentDispositionHeaderValue? Is one more current and more preferred than the other?
– Luminous
May 8 '15 at 16:00
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