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How to convert linq results to HashSet or HashedSet
...
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)
...
R data formats: RData, Rda, Rds etc
...you do with RData.
Rds stores a single R object. Yet, beyond that simple explanation, there are several differences from a "standard" storage. Probably this R-manual Link to readRDS() function clarifies such distinctions sufficiently.
So, answering your questions:
The difference is not about the...
Why does range(start, end) not include end?
...ich equals len(range(0, 10)). Remember that programmers prefer 0-based indexing.
Also, consider the following common code snippet:
for i in range(len(li)):
pass
Could you see that if range() went up to exactly len(li) that this would be problematic? The programmer would need to explicitly su...
How to remove the first Item from a list?
...
Python List
list.pop(index)
>>> l = ['a', 'b', 'c', 'd']
>>> l.pop(0)
'a'
>>> l
['b', 'c', 'd']
>>>
del list[index]
>>> l = ['a', 'b', 'c', 'd']
>>> del l[0]
>>> l
['b', 'c', 'd']
&g...
Is there any difference between “!=” and “” in Oracle Sql?
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No there is no difference at all in functionality.
(The same is true for all other DBMS - most of them support both styles):
Here is the current SQL reference: https://docs.oracle.com/database/121/SQLRF/conditions002.htm#CJAGAABC
The SQL standard only...
java: Class.isInstance vs Class.isAssignableFrom
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Both answers are in the ballpark but neither is a complete answer.
MyClass.class.isInstance(obj) is for checking an instance. It returns true when the parameter obj is non-null and can be cast to MyClass without raising a ClassCastException. In ot...
Adding a regression line on a ggplot
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In general, to provide your own formula you should use arguments x and y that will correspond to values you provided in ggplot() - in this case x will be interpreted as x.plot and y as y.plot. More information about smoothing methods and formula you can find in help page of function stat_s...
How to grey out a button?
... disabled by setting the alpha (making it semi-transparent). This is especially useful if your button background is an image, and you don't want to create states for it.
button.setAlpha(.5f);
button.setClickable(false);
update: I wrote the above solution pre Kotlin and when I was a rookie. It's m...
Swift - encode URL
...= "test/test"
let escapedString = originalString.addingPercentEncoding(withAllowedCharacters: .urlHostAllowed)
print(escapedString!)
Output:
test%2Ftest
Swift 1
In iOS 7 and above there is stringByAddingPercentEncodingWithAllowedCharacters
var originalString = "test/test"
var escapedString...
C++ stl stack/queue 的使用方法 - C/C++ - 清泛网 - 专注C/C++及内核技术
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stack<string> s2;
stack 的基本操作有：
入栈，如例：s.push(x);
出栈，如例：s.pop(); 注意，出栈操作只是删除栈顶元素，并不返回该元素，使用top()访问元素。
访问栈顶，如例：s.top()
判断栈空，如例：s.empty()，当栈空时，返回tru...