Signature | Description | Parameters |
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#include <DataFrame/DataFrameStatsVisitors.h> template<typename F, typename T, typename I = unsigned long, std::size_t A = 0> struct ExpandingRollAdopter; |
This is a “single action visitor”, meaning it is passed the whole data vector in one call and you must use the single_act_visit() interface. This functor applies functor F to the data in an expanding rolling progression. The roll count and the step increment count are given to the constructor. The result is a vector of T type values. The first roll_count items, in the result, will be NAN. ExpandingRollAdopter(F &&functor, size_t roll_count, size_t increment_count = 1); |
F: Functor type T: Column data type I: Index type A: Memory alignment boundary for vectors. Default is system default alignment |
static void test_ExpandingRollAdopter() { std::cout << "\nTesting ExpandingRollAdopter{ } ..." << std::endl; std::vector<unsigned long> idx = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 31, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40 }; std::vector<double> d1 = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40 }; MyDataFrame df; df.load_data(std::move(idx), std::make_pair("col_1", d1)); ExpandingRollAdopter<MeanVisitor<double>, double> expand_roller(MeanVisitor<double>(), 2); const auto &result = df.single_act_visit<double>("col_1", expand_roller).get_result(); assert(result.size() == 21); assert(std::isnan(result[0])); assert(result[8] == 12); assert(result[13] == 19.5); assert(result[15] == 22.5); assert(result[20] == 30); }