| Signature | Description | Parameters |
|---|---|---|
template<equality_default_construct ... Ts> DataFrame difference(const DataFrame &other) const; |
This returns a DataFrame that is the difference between self and other. The returned DataFrame has the exact same index column as self. For each column in self and other with the same name, the returned column is the difference between them. For each comparison between pairs of columns, there will be two columns in the returned DataFrame, if there is a difference between them. Their names are prepended with "self_" and "other_". The returned column has the value that is different on spots that there is a difference. In spots that there is no difference there will be a NaN or default value for the type. Columns that are in one DataFrame but not the other are ignored and they are not in the returned DataFrame. It returns a new DataFrame. Self will be unchanged. NOTE: Index type and all data types must have equality (== !=) operators well defined. NOTE: All data column types must have default construction well defined. NOTE: Columns in self and other with the same name must have the same type. NOTE: The index columns in self and other must be identical. |
Ts: The list of types for all columns. A type should be specified only once. other: The other DataFrame to compae with. |
static void test_difference() { std::cout << "\nTesting difference( ) ..." << std::endl; MyDataFrame df; StlVecType<unsigned long> idxvec = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 }; StlVecType<double> dblvec = { 0, 15, -14, 2, 1, 12, 11, 8, 7, 6, 5, 4, 3, 9, 10}; StlVecType<double> dblvec2 = { 100, 101, 102, 103, 104, 103.9, 106.55, 106.34, 1.8, 111, 112, 111.5, 114, 115, 116}; StlVecType<std::string> strvec = { "zz", "bb", "cc", "ww", "ee", "ff", "gg", "hh", "ii", "jj", "kk", "ll", "mm", "nn", "oo" }; df.load_data(std::move(idxvec), std::make_pair("dbl_col", dblvec), std::make_pair("dbl_col_2", dblvec2), std::make_pair("str_col", strvec)); MyDataFrame df2 = df; df2.get_column<double>("dbl_col")[3] = 1000.0; df2.get_column<double>("dbl_col")[6] = 1001.0; df2.get_column<std::string>("str_col")[1] = "Changed"; df2.get_column<std::string>("str_col")[5] = "Changed 2"; MyDataFrame diff_df = df.difference<double, std::string>(df2); assert((diff_df.get_index() == StlVecType<unsigned long>{ 1, 2, 3, 4, 5, 6, 7 })); assert(diff_df.get_column<double>("self_dbl_col").size() == 7); assert(diff_df.get_column<double>("other_dbl_col").size() == 7); assert(std::isnan(diff_df.get_column<double>("self_dbl_col")[0])); assert(std::isnan(diff_df.get_column<double>("other_dbl_col")[0])); assert(std::isnan(diff_df.get_column<double>("self_dbl_col")[1])); assert(std::isnan(diff_df.get_column<double>("other_dbl_col")[1])); assert(diff_df.get_column<double>("self_dbl_col")[3] == 2.0); assert(diff_df.get_column<double>("other_dbl_col")[3] == 1000.0); assert(std::isnan(diff_df.get_column<double>("self_dbl_col")[4])); assert(std::isnan(diff_df.get_column<double>("other_dbl_col")[4])); assert(diff_df.get_column<double>("self_dbl_col")[6] == 11.0); assert(diff_df.get_column<double>("other_dbl_col")[6] == 1001.0); assert(diff_df.get_column<std::string>("self_str_col").size() == 6); assert(diff_df.get_column<std::string>("other_str_col").size() == 6); assert(diff_df.get_column<std::string>("self_str_col")[0] == ""); assert(diff_df.get_column<std::string>("other_str_col")[0] == ""); assert(diff_df.get_column<std::string>("self_str_col")[1] == "bb"); assert(diff_df.get_column<std::string>("other_str_col")[1] == "Changed"); assert(diff_df.get_column<std::string>("self_str_col")[2] == ""); assert(diff_df.get_column<std::string>("other_str_col")[2] == ""); assert(diff_df.get_column<std::string>("self_str_col")[5] == "ff"); assert(diff_df.get_column<std::string>("other_str_col")[5] == "Changed 2"); assert(! diff_df.has_column("self_dbl_col_2")); assert(! diff_df.has_column("other_dbl_col_2")); assert(! diff_df.has_column("dbl_col_2")); }
