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List distinct values in a vector in R
...els( data$product_code )
If it's not a factor, but it should be, you can convert it to factor first by using the factor() function, e.g.
levels( factor( data$product_code ) )
Another option, as mentioned above, is the unique() function:
unique( data$product_code )
The main difference between...
Newline in markdown table?
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The <BR> syntax works only when you convert to HTML - at least in pandoc.
– halloleo
Jul 5 '15 at 4:11
3
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Difference between res.send and res.json in Express.js
... are identical when an object or array is passed, but res.json() will also convert non-objects, such as null and undefined, which are not valid JSON.
The method also uses the json replacer and json spaces application settings, so you can format JSON with more options. Those options are set like so:...
Difference between reduce and foldLeft/fold in functional programming (particularly Scala and Scala
Why do Scala and frameworks like Spark and Scalding have both reduce and foldLeft ? So then what's the difference between reduce and fold ?
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Pointers vs. values in parameters and return values
...n doubt, use a pointer."
Slices, maps, channels, strings, function values, and interface values are implemented with pointers internally, and a pointer to them is often redundant.
Elsewhere, use pointers for big structs or structs you'll have to change, and otherwise pass values, because getting thi...
How to load external webpage inside WebView
...anks to this post, I finally found the solution. Here is the code:
import android.app.Activity;
import android.os.Bundle;
import android.webkit.WebResourceError;
import android.webkit.WebResourceRequest;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.Toast...
Parsing boolean values with argparse
...to do --flag False or --other-flag True and then use some custom parser to convert the string to a boolean.. action='store_true' and action='store_false' are the best ways to use boolean flags
– kevlarr
Mar 20 '18 at 14:23
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How to use a variable for the key part of a map
...(X):2]
For the value-part it's even easier, since there is no automagic "convert text to string" happening:
def map = [keyA:A, keyX:X]
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Importing a CSV file into a sqlite3 database table using Python
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I keep getting not all arguments converted during string formatting when I attempt this method.
– Whitecat
Sep 1 '16 at 23:27
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How to check if an element is in an array
...y? Xcode does not have any suggestions for contain , include , or has , and a quick search through the book turned up nothing. Any idea how to check for this? I know that there is a method find that returns the index number, but is there a method that returns a boolean like ruby's #include? ?
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