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Determine the number of NA values in a column
...nt the number of NA values in a data frame column. Say my data frame is called df , and the name of the column I am considering is col . The way I have come up with is following:
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Rails 3 migrations: Adding reference column?
...d:
rails g migration add_user_id_to_tester user_id:integer
And then manually add belongs_to :user in the Tester model
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How to set the UITableView Section title programmatically (iPhone/iPad)?
... answered May 8 '12 at 20:27
AlladinianAlladinian
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UnmodifiableMap (Java Collections) vs ImmutableMap (Google) [duplicate]
...// Will return "F".
In contrast to that, the ImmutableMap of Guava is really immutable: It is a true copy of a given map, and nobody may modify this ImmutableMap in any way.
Update:
As pointed out in a comment, an immutable map can also be created with the standard API using
Map<String, S...
Getting the first index of an object
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For a one liner to work in all browsers including IE8 and below use for (var key in obj) if (obj.hasOwnProperty(key)) break; You'll then want to use the key variable
– Ally
Sep 6 '13 at 16:23
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How to unbind a listener that is calling event.preventDefault() (using jQuery)?
jquery toggle calls preventDefault() by default, so the defaults don't work.
you can't click a checkbox, you cant click a link etc etc
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Get String in YYYYMMDD format from JS date object?
... won't need the rightNow variable around, you can wrap new Date and get it all back in a single line: (new Date()).toISOString().slice(0,10).replace(/-/g,"")
– BigBlueHat
Sep 26 '13 at 17:43
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Java Array Sort descending?
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You could use this to sort all kind of Objects
sort(T[] a, Comparator<? super T> c)
Arrays.sort(a, Collections.reverseOrder());
Arrays.sort() cannot be used directly to sort primitive arrays in descending order. If you try to call the Arrays...
HTML5 placeholder css padding
...ut padding is not the best solution. The best is to use (and I know it normally never does anything, but in this case it does) the VERTICAL-ALIGN CSS property.
– RIK
Oct 2 '11 at 13:02
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Hudson vs Jenkins in 2012 [closed]
...e more assured about the stability and support of the software they're installing.
Every three months or so, a previous release is selected which has been deemed as working well by the community of Jenkins users. This version is then branched, any important fixes (which have been "battle-tested") ...