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How to append rows to an R data frame
...<- function(n){
df <- data.frame(x = numeric(n), y = character(n), stringsAsFactors = FALSE)
for(i in 1:n){
df$x[i] <- i
df$y[i] <- toString(i)
}
df
}
Here's a similar approach, but one where the data.frame is created as the last step.
# Use preallocated vectors
f4 <...
How to replace a hash key with another key
...
If all the keys are strings and all of them have the underscore prefix, then you can patch up the hash in place with this:
h.keys.each { |k| h[k[1, k.length - 1]] = h[k]; h.delete(k) }
The k[1, k.length - 1] bit grabs all of k except the firs...
Getting the name of a variable as a string
This thread discusses how to get the name of a function as a string in Python:
How to get a function name as a string?
23 ...
Smart way to truncate long strings
Does anyone have a more sophisticated solution/library for truncating strings with JavaScript and putting an ellipsis on the end, than the obvious one:
...
How do I view the full content of a text or varchar(MAX) column in SQL Server 2008 Management Studio
... and extra rows all become concatenated with the first one. Finally if the string contains characters such as < opening the XML viewer fails with a parsing error.
A more robust way of doing this that avoids issues of SQL Server converting < to &lt; etc or failing due to these characters i...
Why .NET String is immutable? [duplicate]
As we all know, String is immutable. What are the reasons for String being immutable and the introduction of StringBuilder class as mutable?
...
MySQL - Rows to Columns
...le of years late, I had to use MAX instead of SUM because my itemValue are strings, not numerical values.
– Merricat
Jun 17 at 17:55
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Add new methods to a resource controller in Laravel
...Determine if the current route matches a given name.
*
* @param string $name
* @return bool
*/
public static function is($name)
{
return static::$app['router']->currentRouteNamed($name);
}
/**
* Determine if the current route uses a given contro...
Comparing Dates in Oracle SQL
...
31-DEC-95 isn't a string, nor is 20-JUN-94. They're numbers with some extra stuff added on the end. This should be '31-DEC-95' or '20-JUN-94' - note the single quote, '. This will enable you to do a string comparison.
However, you're not doin...
Convert JsonNode into POJO
...e(fileReader, MyClass.class);
I say should because I'm using that with a String, not a BufferedReader but it should still work.
Here's my code:
String inputString = // I grab my string here
MySessionClass sessionObject;
try {
ObjectMapper objectMapper = new ObjectMapper();
sessionObject ...