std::slice
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<metanoindex/>
<tbody> </tbody>| Dclar dans l'en-tte <valarray>
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class slice; |
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std::slice est le slecteur de classe qui identifie un sous-ensemble de std::valarray similaire tranche BLAS. Un objet de type de std::slice contient trois valeurs: l'index de dpart, le pas et le nombre total de valeurs dans le sous-ensemble. Objets de std::slice type peut tre utilis comme index avec operator[] valarray de .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.
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Fonctions membres
construit une tranche 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. (fonction membre publique) | |
accde au dbut de la tranche 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. (fonction membre publique) | |
accde la taille de la tranche 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. (fonction membre publique) | |
accde la foule de la tranche 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. (fonction membre publique) | |
Exemple
Barebones classe Matrix valarray soutenu avec une fonction tracer calcul .
Original:
Barebones valarray-backed Matrix class with a tracer calculating function.
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
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#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';
}
Rsultat :
Trace of the matrix (1,2,3) (4,5,6) (7,8,9) is 15
Voir aussi
get / set lment valarray, tranche, ou un masque 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. (fonction membre publique) | |
tranche gnralise d'une valarray: indice de dpart, un ensemble de longueurs, jeu de progrs 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. (classe) | |
procuration d'un sous-ensemble d'un valarray aprs l'application d'une tranche 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. (classe gnrique) | |