numeric

问题 This doesn't compile because Initializer 'init(_:)' requires that 'Number' conform to 'BinaryInteger' struct Percentage<Number: Numeric> { let value: Number let total: Number var percentage: Double { Double(value) / Double(total) } } Does anyone have a nice solution? To give some context to the problem from real life: I'm coding a SwiftUI app, that has a CircularProgress-view. I would like to use the same CircularProgress-view with different number types and to be able to show the current

问题 This question already has answers here : What does iota of std::iota stand for? (5 answers) Closed 6 years ago . C++11 introduced a function called iota. Which "Assigns to every element in the range [first,last) successive values of val, as if incremented with ++val after each element is written." Can someone explain what "iota" means here though? I looked up "iota" and it seems to have nothing to do with generating a range. 回答1: Quoting this non-authoritative, but nonetheless correct, wiki:

问题 This question already has answers here : What does iota of std::iota stand for? (5 answers) Closed 6 years ago . C++11 introduced a function called iota. Which "Assigns to every element in the range [first,last) successive values of val, as if incremented with ++val after each element is written." Can someone explain what "iota" means here though? I looked up "iota" and it seems to have nothing to do with generating a range. 回答1: Quoting this non-authoritative, but nonetheless correct, wiki:

问题 This question already has answers here : What does iota of std::iota stand for? (5 answers) Closed 6 years ago . C++11 introduced a function called iota. Which "Assigns to every element in the range [first,last) successive values of val, as if incremented with ++val after each element is written." Can someone explain what "iota" means here though? I looked up "iota" and it seems to have nothing to do with generating a range. 回答1: Quoting this non-authoritative, but nonetheless correct, wiki:

问题 This question already has answers here : What does iota of std::iota stand for? (5 answers) Closed 6 years ago . C++11 introduced a function called iota. Which "Assigns to every element in the range [first,last) successive values of val, as if incremented with ++val after each element is written." Can someone explain what "iota" means here though? I looked up "iota" and it seems to have nothing to do with generating a range. 回答1: Quoting this non-authoritative, but nonetheless correct, wiki:

问题 This question already has answers here : What does iota of std::iota stand for? (5 answers) Closed 6 years ago . C++11 introduced a function called iota. Which "Assigns to every element in the range [first,last) successive values of val, as if incremented with ++val after each element is written." Can someone explain what "iota" means here though? I looked up "iota" and it seems to have nothing to do with generating a range. 回答1: Quoting this non-authoritative, but nonetheless correct, wiki:

问题 Searched Google and SO and couldn't find a good answer. I have the following table: Country Value 23 Bolivia 2575.684 71 Guyana 3584.693 125 Paraguay 3878.150 49 Ecuador 5647.638 126 Peru 6825.461 38 Colombia 7752.168 151 Suriname 9376.495 25 Brazil 11346.796 7 Argentina 11610.220 171 Venezuela 12766.725 168 Uruguay 14702.505 37 Chile 15363.098 All values are in US dollars - I'd like to add in the dollar signs and the commas. Bolivia's value should therefore read $2,575.684. Also, is there

问题 How to select integer values only from a varchar column in PostgreSQL? If the column contains: abc 70 3g 71 1.5 I'd like to select only: 70 71 I'm struggling to find functions like: is_numeric, is_integer, to do something like this: SELECT column FROM table WHERE isinteger(column) Any ideas? Thank you. 回答1: SELECT column FROM table WHERE column ~ '^\d+$' 来源： https://stackoverflow.com/questions/15163793/how-to-select-integer-values-only-from-a-varchar-column-in-postgresql

问题 How to select integer values only from a varchar column in PostgreSQL? If the column contains: abc 70 3g 71 1.5 I'd like to select only: 70 71 I'm struggling to find functions like: is_numeric, is_integer, to do something like this: SELECT column FROM table WHERE isinteger(column) Any ideas? Thank you. 回答1: SELECT column FROM table WHERE column ~ '^\d+$' 来源： https://stackoverflow.com/questions/15163793/how-to-select-integer-values-only-from-a-varchar-column-in-postgresql

问题 I have the following data set data date PX_LAST.USGG10YR Index PX_LAST.GSWISS10 Index 1 2012-12-31 1.7574 0.526 2 2013-01-31 1.9849 0.789 3 2013-02-28 1.8756 0.698 4 2013-03-29 1.8486 0.716 5 2013-04-30 1.6717 0.570 6 2013-05-31 2.1282 0.722 7 2013-06-28 2.4857 1.027 8 2013-07-31 2.5762 1.023 9 2013-08-30 2.7839 1.069 10 2013-09-30 2.6100 1.021 The class of the date column is > class(data[,1]) [1] "POSIXct" "POSIXt" The class of the other two columns is class(data[,2]) [1] "numeric" class