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Convert column classes in data.table
I have a problem using data.table: How do I convert column classes? Here is a simple example: With data.frame I don't have a problem converting it, with data.table I just don't know how:
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How to print color in console using System.out.println?
...in). For example, you could define constants like these for the colors:
public static final String ANSI_RESET = "\u001B[0m";
public static final String ANSI_BLACK = "\u001B[30m";
public static final String ANSI_RED = "\u001B[31m";
public static final String ANSI_GREEN = "\u001B[32m";
public static ...
What does curly brackets in the `var { … } = …` statements do?
Not sure if this is a Mozilla-specific JS syntax, but I often found variables being declared this way, for example, in add-on SDK docs :
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Clone Object without reference javascript [duplicate]
I have a big object with much data. And i want to clone this in other variable. When i set some param of the instance B has the same result in the original object:
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New self vs. new static
I am converting a PHP 5.3 library to work on PHP 5.2. The main thing standing in my way is the use of late static binding like return new static($options); , if I convert this to return new self($options) will I get the same results?
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How can I merge two commits into one if I already started rebase?
...ying to merge 2 commits into 1, so I followed “squashing commits with rebase” from git ready .
11 Answers
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Iterate over a Javascript associative array in sorted order
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You cannot iterate over them directly, but you can find all the keys and then just sort them.
var a = new Array();
a['b'] = 1;
a['z'] = 1;
a['a'] = 1;
function keys(obj)
{
var keys = [];
for(var key in obj)
{
if(obj.hasOwnProperty(key))
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How can I pass a member function where a free function is expected?
...ing wrong with using function pointers. However, pointers to non-static member functions are not like normal function pointers: member functions need to be called on an object which is passed as an implicit argument to the function. The signature of your member function above is, thus
void (aClass:...
pandas: multiple conditions while indexing data frame - unexpected behavior
I am filtering rows in a dataframe by values in two columns.
3 Answers
3
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What's the algorithm to calculate aspect ratio?
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I gather you're looking for an usable aspect ratio integer:integer solution like 16:9 rather than a float:1 solution like 1.77778:1.
If so, what you need to do is find the greatest common divisor (GCD) and divide both values by that. The GCD is the highest n...