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Add new row to dataframe, at specific row-index, not appended?
...ds 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
existin...
git: Show index diff in commit message as comment
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answered Jan 20 '11 at 17:09
Alan Haggai AlaviAlan Haggai Alavi
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How to insert a character in a string at a certain position?
...igit value. I want to display it as a String with a decimal point (.) at 2 digits from the end of int . I wanted to use a float but was suggested to use String for a better display output (instead of 1234.5 will be 1234.50 ). Therefore, I need a function that will take an int as paramete...
Ruby: What is the easiest way to remove the first element from an array?
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291
"pop"ing the first element of an Array is called "shift" ("unshift"
being the operation of add...
Clojure: cons (seq) vs. conj (list)
...guments to insert into a collection, while cons takes just one:
(conj '(1 2 3) 4 5 6)
; => (6 5 4 1 2 3)
(cons 4 5 6 '(1 2 3))
; => IllegalArgumentException due to wrong arity
Another difference is in the class of the return value:
(class (conj '(1 2 3) 4))
; => clojure.lang.Persistent...
What is the use of Enumerable.Zip extension method in Linq?
...ers= new string[] { "A", "B", "C", "D", "E" };
var numbers= new int[] { 1, 2, 3 };
var q = letters.Zip(numbers, (l, n) => l + n.ToString());
foreach (var s in q)
Console.WriteLine(s);
Ouput
A1
B2
C3
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CPU Privilege Rings: Why rings 1 and 2 aren't used?
...of the modern protection model) only has a concept of privileged (ring 0,1,2) and unprivileged, the benefit to rings 1 and 2 were diminished greatly.
The intent by Intel in having rings 1 and 2 is for the OS to put device drivers at that level, so they are privileged, but somewhat separated from th...
What's the syntax for mod in java
...s, you can use the remainder operator %. For your exact example:
if ((a % 2) == 0)
{
isEven = true;
}
else
{
isEven = false;
}
This can be simplified to a one-liner:
isEven = (a % 2) == 0;
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What is the difference between substr and substring?
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Delan AzabaniDelan Azabani
70.4k2222 gold badges154154 silver badges189189 bronze badges
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How to parse JSON in Python?
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Very simple:
import json
data = json.loads('{"one" : "1", "two" : "2", "three" : "3"}')
print data['two']
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