std::slice
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| definiert in Header <valarray>
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| class slice; |
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std::slice ist der Selektor Klasse, die eine Teilmenge von std::valarray ähnlich BLAS Scheibe identifiziert. Ein Objekt des Typs std::slice hält drei Werte: die Startindex, die Schrittlänge und die Gesamtzahl der Werte in der Teilmenge. Objekte vom Typ std::slice können als Indizes mit valarray die operator[] verwendet werden .Original:
std::slice is the selector class that identifies a subset of std::valarray similar to BLAS slice. An object of type std::slice holds three values: the starting index, the stride, and the total number of values in the subset. Objects of type std::slice can be used as indexes with valarray's operator[].The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
You can help to correct and verify the translation. Click here for instructions.
[Bearbeiten] Member-Funktionen
| baut eine Scheibe Original: constructs a slice The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (öffentliche Elementfunktion) | |
| greift auf den Start der Scheibe Original: accesses the start of the slice The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (öffentliche Elementfunktion) | |
| greift auf die Größe der Scheibe Original: accesses the size of the slice The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (öffentliche Elementfunktion) | |
| greift die Schrittlänge der Scheibe Original: accesses the stride of the slice The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (öffentliche Elementfunktion) | |
[Bearbeiten] Beispiel
Barebones valarray-backed Matrix-Klasse mit einem verfolgen Rechenfunktion .
Original:
Barebones valarray-backed Matrix class with a verfolgen calculating function.
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
You can help to correct and verify the translation. Click here for instructions.
#include <iostream> #include <valarray> class Matrix { std::valarray<int> data; int dim; public: Matrix(int r, int c) : data(r*c), dim(c) {} int& operator()(int r, int c) {return data[r*dim + c];} int trace() const { return data[std::slice(0, dim, dim+1)].sum(); } }; int main() { Matrix m(3,3); int n = 0; for(int r=0; r<3; ++r) for(int c=0; c<3; ++c) m(r, c) = ++n; std::cout << "Trace of the matrix (1,2,3) (4,5,6) (7,8,9) is " << m.trace() << '\n'; }
Output:
Trace of the matrix (1,2,3) (4,5,6) (7,8,9) is 15
[Bearbeiten] Siehe auch
| get / set valarray Element, Scheibe, oder Maske Original: get/set valarray element, slice, or mask The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (öffentliche Elementfunktion) | |
| generalisierte Scheibe eines valarray: Startindex, Längen eingestellt, der Fortschritte festgelegt Original: generalized slice of a valarray: starting index, set of lengths, set of strides The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (Klasse) | |
| Proxy auf eine Teilmenge eines valarray nach Anwendung einer Scheibe Original: proxy to a subset of a valarray after applying a slice The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (Klassen-Template) | |
