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Omit rows containing specific column of NA

... You could use the complete.cases function and put it into a function thusly: DF <- data.frame(x = c(1, 2, 3), y = c(0, 10, NA), z=c(NA, 33, 22)) completeFun <- function(data, desiredCols) { completeVec <- complete.cases(data[, desiredCols]) return(data...
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Difference between `npm start` & `node app.js`, when starting app?

I have installed an application using the command express new 'filename' . I have just learned that you can start an application using: ...
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Stop form refreshing page on submit

...fault(); }); Of course, in the function, you can check for empty fields, and if anything doesn't look right, e.preventDefault() will stop the submit. Without jQuery: var form = document.getElementById("myForm"); function handleForm(event) { event.preventDefault(); } form.addEventListener('submi...
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Creating a jQuery object from a big HTML-string

...le.net/MCSyr/2/ It parses the arbitrary HTML string into a jQuery object, and uses find to display the result in a div. share | improve this answer | follow |...
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Pass Additional ViewData to a Strongly-Typed Partial View

I have a strongly-typed Partial View that takes a ProductImage and when it is rendered I would also like to provide it with some additional ViewData which I create dynamically in the containing page. How can I pass both my strongly typed object and my custom ViewData to the partial view with the Ren...
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What is the Swift equivalent of respondsToSelector?

...ional unwrapper operator. This allows you to call a method on an object if and only if the object exists (not nil) and the method is implemented. In the case where you still need respondsToSelector:, it is still there as part of the NSObject protocol. If you are calling respondsToSelector: on an O...
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How do I use floating-point division in bash?

...$IMG_WIDTH/$IMG2_WIDTH") without $(( )) (double parentheses) ; which is expanded by the bash before executing command – Nahuel Fouilleul Oct 4 '12 at 7:32 ...
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Why isn't vector a STL container?

...eyers's book Effective STL: 50 Specific Ways to Improve Your Use of the Standard Template Library says to avoid vector <bool> as it's not an STL container and it doesn't really hold bool s. ...
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Fastest check if row exists in PostgreSQL

... sometimes None (depending on your programing language) which might not expand the way you expect. – isaaclw Jun 10 '14 at 23:18 1 ...
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How to elegantly rename all keys in a hash in Ruby? [duplicate]

... Just use mappings[k] || k instead of mappings[k] above and it will leave keys not in the mapping as is. – Mladen Jablanović Nov 9 '10 at 20:26 ...