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Statistics: combinations in Python
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@robertking - Ok, you were both petty and technically correct. What i did was meant as illustration of how to write one's own function; i knew it is not accurate for big enough N and K due to floating point precision. But we can fix that - see above, now it should not err f...
How to set input type date's default value to today?
...ides enough built-in support for the required format to avoid doing it manually:
Add this for correct timezone support:
Date.prototype.toDateInputValue = (function() {
var local = new Date(this);
local.setMinutes(this.getMinutes() - this.getTimezoneOffset());
return local.toJSON().slic...
How can two strings be concatenated?
...','b'),'blah', c(1,2,3)) results in "a blah 1" "b blah 2" "a blah 3". Basically, it creates a vector of strings the same length as the longest vector that's passed in, and loops the other vectors/strings to the same length. Plenty of room for accidental behaviour there.
– naugh...
Android: show soft keyboard automatically when focus is on an EditText
...x using AlertDialog . The EditText inside the dialog itself is automatically focused when I call AlertDialog.show() , but the soft keyboard is not automatically shown.
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What's the difference between “ ” and “ ”?
...ers are supposed to be self-contained. An outside link to codepen is also allowed, if the full answer is also included in the post directly. To adhere to SO policy, edit your post to either include the resulting output of the code in your answer, or to add SO's own embedded version of codepen, so ...
How to group time by hour or by 10 minutes
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finally done with
GROUP BY
DATEPART(YEAR, DT.[Date]),
DATEPART(MONTH, DT.[Date]),
DATEPART(DAY, DT.[Date]),
DATEPART(HOUR, DT.[Date]),
(DATEPART(MINUTE, DT.[Date]) / 10)
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Best practices/performance: mixing StringBuilder.append with String.concat
...t can fit both s1 and s2. Copies s1 and s2 contents to this new array. Actually requires less work then + operator.
StringBuilder.append()
Maintains an internal char[] array that grows when needed. No extra char[] is created if the internal one is sufficiently big.
stringBuilder.append(s1.concat(...
How to establish a connection pool in JDBC?
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Usually if you need a connection pool you are writing an application that runs in some managed environment, that is you are running inside an application server. If this is the case be sure to check what connection pooling facil...
Iterating through a list in reverse order in java
...es the elegance of the for each syntax. +1 anyway.
– Allain Lalonde
Jan 20 '10 at 15:35
26
Callin...
How to convert linq results to HashSet or HashedSet
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I don't think there's anything built in which does this... but it's really easy to write an extension method:
public static class Extensions
{
public static HashSet<T> ToHashSet<T>(
this IEnumerable<T> source,
IEqualityComparer<T> comparer = null)
...