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Best way to make Java's modulus behave like it should with negative numbers?
...the negative values of a, since (a % b) is a negative value between -b and 0, (a % b + b) is necessarily lower than b and positive. The last modulo is there in case a was positive to begin with, since if a is positive (a % b + b) would become larger than b. Therefore, (a % b + b) % b turns it into s...
Replacing a 32-bit loop counter with 64-bit introduces crazy performance deviations with _mm_popcnt_
... loop variable from unsigned to uint64_t made the performance drop by 50% on my PC.
10 Answers
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Relative frequencies / proportions with dplyr
...n = n()) %>%
mutate(freq = n / sum(n))
# am gear n freq
# 1 0 3 15 0.7894737
# 2 0 4 4 0.2105263
# 3 1 4 8 0.6153846
# 4 1 5 5 0.3846154
From the dplyr vignette:
When you group by multiple variables, each summary peels off one level of the grouping. That makes ...
Static variables in member functions
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iammilindiammilind
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How to sort a list in Scala by two fields?
...g.String) ).
– senia
Jun 18 '14 at 10:16
5
@SachinK: You could implement customOrdering as Orderi...
ObservableCollection not noticing when Item in it changes (even with INotifyPropertyChanged)
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120
The ContentList's Set method will not get called when you change a value inside the collection, ...
The modulo operation on negative numbers in Python
...nually fix it up by adding 7:
int result = (2 - N) % 7;
return result < 0 ? result + 7 : result;
(See http://en.wikipedia.org/wiki/Modulo_operator for how the sign of result is determined for different languages.)
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How can I make pandas dataframe column headers all lowercase?
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180
You can do it like this:
data.columns = map(str.lower, data.columns)
or
data.columns = [x.lo...
Regex how to match an optional character
...e letter optional. {1} is redundant. (Of course you could also write [A-Z]{0,1} which would mean the same, but that's what the ? is there for.)
You could improve your regex to
^([0-9]{5})+\s+([A-Z]?)\s+([A-Z])([0-9]{3})([0-9]{3})([A-Z]{3})([A-Z]{3})\s+([A-Z])[0-9]{3}([0-9]{4})([0-9]{2})([0-9]{2})
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How to remove the querystring and get only the url?
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+100
You can use strtok to get string before first occurence of ?
$url = strtok($_SERVER["REQUEST_URI"], '?');
strtok() represents the ...