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Add new row to dataframe, at specific row-index, not appended?
...s the (often slow) rbind call:
existingDF <- as.data.frame(matrix(seq(20),nrow=5,ncol=4))
r <- 3
newrow <- seq(4)
insertRow <- function(existingDF, newrow, r) {
existingDF[seq(r+1,nrow(existingDF)+1),] <- existingDF[seq(r,nrow(existingDF)),]
existingDF[r,] <- newrow
existing...
Get String in YYYYMMDD format from JS date object?
... this.getDate();
return [this.getFullYear(),
(mm>9 ? '' : '0') + mm,
(dd>9 ? '' : '0') + dd
].join('');
};
var date = new Date();
date.yyyymmdd();
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imp...
Append an object to a list in R in amortized constant time, O(1)?
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R>
That works on vectors too, so do I get the bonus points?
Edit (2015-Feb-01): This post is coming up on its fifth birthday. Some kind readers keep repeating any shortcomings with it, so by all means also see some of the comments below. One suggestion for list types:
newlist <- list(ol...
Get Image size WITHOUT loading image into memory
...e operations in the source like:
...
prefix = fp.read(16)
...
fp.seek(0)
...
but these hardly constitute reading the whole file. In fact .open simply returns a file object and the filename on success. In addition the docs say:
open(file, mode=”r”)
Opens and identifies the given ...
How would you compare jQuery objects?
...
You need to compare the raw DOM elements, e.g.:
if ($(this).parent().get(0) === $('body').get(0))
or
if ($(this).parent()[0] === $('body')[0])
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Run a single Maven plugin execution?
... parameter, e.g., org.apache.maven.plugins:maven-remote-resources-plugin:1.0:process@executionId.
So, as long as you give your execution an id:
mvn sql:execute@specific-execution-id
uses the execution configured in your pom.
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Is Big O(logn) log base e?
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edited Feb 15 '10 at 5:23
community wiki
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Java code To convert byte to Hexadecimal
...
byte[] bytes = {-1, 0, 1, 2, 3 };
StringBuilder sb = new StringBuilder();
for (byte b : bytes) {
sb.append(String.format("%02X ", b));
}
System.out.println(sb.toString());
// prints "FF 00 01 02 03 "
See also
java...
How to use WinForms progress bar?
...id button1_Click(object sender, EventArgs e)
{
progressBar1.Maximum = 100;
progressBar1.Step = 1;
progressBar1.Value = 0;
backgroundWorker.RunWorkerAsync();
}
private void backgroundWorker_DoWork(object sender, DoWorkEventArgs e)
{
var backgroundWorker = sender as BackgroundWork...
ObservableCollection not noticing when Item in it changes (even with INotifyPropertyChanged)
...
120
The ContentList's Set method will not get called when you change a value inside the collection, ...