RecArrayCreation

class numpy::RecArrayCreation

numpy C++ class.

Example

#include <numpy/np_ndarray.h>
using namespace numpy;

// Use RecArrayCreation
RecArrayCreation obj;
// ... operations ...

Array Creation

Signature	Return Type	Location	Example
RecordArray ones(const std::vector<size_t>&shape, std::shared_ptr<StructuredDType>dtype)	RecordArray	NP_REC_CREATION.H:233	View
RecordArray zeros(const std::vector<size_t>&shape, std::shared_ptr<StructuredDType>dtype)	RecordArray	NP_REC_CREATION.H:208	View

Indexing / Selection

Signature	Return Type	Location	Example
DType getDTypeFromType()	DType	NP_REC_CREATION.H:279
DType getDTypeFromValue(const StructuredValue &value)	DType	NP_REC_CREATION.H:272

I/O

Signature	Return Type	Location	Example
RecordArray fromfile(const std::string &filename, std::shared_ptr<StructuredDType>dtype, const std::string &separator = ",", size_tcount = SIZE_MAX, boolskip_header = false)	RecordArray	NP_REC_CREATION.H:173	View
RecordArray fromstring(const std::string &data, std::shared_ptr<StructuredDType>dtype, const std::string &separator = ",", size_tcount = SIZE_MAX)	RecordArray	NP_REC_CREATION.H:155	View

Other Methods

Signature	Return Type	Location	Example
RecordArray array(const std::vector<std::tuple<Args...>>&data, const std::vector<std::pair<std::string,DType>>&field_specs)	RecordArray	NP_REC_CREATION.H:202	View
RecordArray fromarrays(const std::vector<std::pair<std::string,NDArray<T>>>&field_arrays)	RecordArray	NP_REC_CREATION.H:63	View
RecordArray fromarrays(const std::vector<std::pair<std::string,std::pair<DType,std::shared_ptr<void>>>>&field_data, const std::vector<size_t>&shape)	RecordArray	NP_REC_CREATION.H:107	View
RecordArray fromrecords(const std::vector<std::tuple<Args...>>&records, const std::vector<std::pair<std::string,DType>>&field_specs)	RecordArray	NP_REC_CREATION.H:14	View
RecordArray fromrecords(const std::vector<StructuredRecord>&records, std::shared_ptr<StructuredDType>dtype)	RecordArray	NP_REC_CREATION.H:31	View
RecordArray fromrecords(const std::vector<StructuredRecord>&records)	RecordArray	NP_REC_CREATION.H:46	View
StructuredRecord parseRecordFromString(const std::string &line, std::shared_ptr<StructuredDType>dtype, const std::string &separator)	StructuredRecord	NP_REC_CREATION.H:320
StructuredValue parseValueFromString(const std::string &str, DTypedtype)	StructuredValue	NP_REC_CREATION.H:342
void setFieldFromRawData(RecordArray &array, const std::vector<size_t>&indices, const std::string &field_name, DTypedtype, void \*data, size_toffset)	void	NP_REC_CREATION.H:296
void setFieldFromTupleElement(RecordArray &array, const std::vector<size_t>&indices, const std::string &field_name, const T &value)	void	NP_REC_CREATION.H:266
void setOneValue(RecordArray &array, const std::vector<size_t>&indices, const std::string &field_name, DTypedtype)	void	NP_REC_CREATION.H:393
void setRecordFromTuple(RecordArray &array, const std::vector<size_t>&indices, const Tuple &tuple, std::index_sequence<Is...>)	void	NP_REC_CREATION.H:259
void setZeroValue(RecordArray &array, const std::vector<size_t>&indices, const std::string &field_name, DTypedtype)	void	NP_REC_CREATION.H:373

Code Examples

The following examples are extracted from the test suite.

ones (np_test_1_all.cpp:319)

  //int_range.printArray();

  auto reshaped = int_range.reshapeArray({ 3, 2 });
  // std::cout << "Reshaped to 2x2 matrix:";
  //reshaped.printArray();

  auto zeros = createInt32Zeros({ 2, 3 });
  // std::cout << "zeros (2,3):";
  //zeros.printArray();
  auto ones = createInt32Ones({ 2, 3 });
  // std::cout << "ones (2,3):";
  //ones.printArray();

  // std::cout << "Addition of zeros and ones:" << std::endl;
  auto sum = zeros.addArrays(ones);
  //sum.printArray();

  // std::cout << "Sum of all elements: " << sum.sumArray() << std::endl;
  // std::cout << "Mean: " << sum.meanArray() << std::endl;

  // std::cout << std::endl << "Type introspection with get_typename():" << std::endl;

zeros (np_test_1_all.cpp:316)

  auto int_range = NDArray<int32>::createRange(1, 12, 2);
  // std::cout << "Int32 range array (1 to 10, step 2):" << std::endl;
  //int_range.printArray();

  auto reshaped = int_range.reshapeArray({ 3, 2 });
  // std::cout << "Reshaped to 2x2 matrix:";
  //reshaped.printArray();

  auto zeros = createInt32Zeros({ 2, 3 });
  // std::cout << "zeros (2,3):";
  //zeros.printArray();
  auto ones = createInt32Ones({ 2, 3 });
  // std::cout << "ones (2,3):";
  //ones.printArray();

  // std::cout << "Addition of zeros and ones:" << std::endl;
  auto sum = zeros.addArrays(ones);
  //sum.printArray();

  // std::cout << "Sum of all elements: " << sum.sumArray() << std::endl;

fromfile (np_test_1_all.cpp:26167)

      outfile.close();

      // Define dtype
      std::vector<std::pair<std::string, numpy::DType>> fields = {
          {"id", numpy::DType::INT32},
          {"value", numpy::DType::FLOAT64}
      };
      auto dtype = std::make_shared<numpy::StructuredDType>(fields);

      // Load from file
      auto result = numpy::fromfile(filename, dtype, ",");

      // Verify loaded correctly
      bool passed = (result.getSize() == 3);
      if (passed) {
        passed = (result.getFieldValue<numpy::int32>({ 0 }, "id") == 1);
        passed = passed && (std::abs(result.getFieldValue<numpy::float64>({ 1 }, "value") - 20.5) < 0.001);
      }

      // Clean up temp file
      std::remove(filename.c_str());

fromstring (np_test_1_all.cpp:21885)

    std::cout << "========= testStringParsing =======================";

    auto dtype = std::make_shared<StructuredDType>(std::vector<std::pair<std::string, DType>>{
      {"name", DType::UNICODE32},
      { "age", DType::INT32 },
      { "score", DType::FLOAT64 }
    });

    std::string data = "Alice,25,85.5\nBob,30,92.3\nCharlie,35,78.9";

    auto arr = fromstring(data, dtype, ",", 3);

    // std::cout << "Array created from string data:" << std::endl;
    //arr.printArray();

    auto name_1 = arr.getFieldValue<std::string>({ 1 }, "name");
    auto age_1 = arr.getFieldValue<int32>({ 1 }, "age");
    auto score_1 = arr.getFieldValue<float64>({ 1 }, "score");

    // std::cout << "Verification of record 1:" << std::endl;
    // std::cout << "Name: " << (name_1.size() > 0 ? "Bob" : "empty") << std::endl;

array (np_test_1_all.cpp:243)

    // std::cout << "Min: " << array.minArray() << std::endl;
    // std::cout << "Max: " << array.maxArray() << std::endl;

    std::cout << " -> tests passed" << std::endl;
}

void testReshapeAndFlatten() {
    std::cout << "========= testReshapeAndFlatten =======================";

    auto range_array = NDArray<int32>::createRange(0, 12, 1);
    // std::cout << "Range array (0-11):" << std::endl;
    //range_array.printArray();

    auto reshaped = range_array.reshapeArray({3, 4});
    // std::cout << "Reshaped to 3x4:";
    //reshaped.printArray();

    auto flattened = reshaped.flattenArray();
    // std::cout << "Flattened:" << std::endl;
    //flattened.printArray();

fromarrays (np_test_1_all.cpp:21655)

    ids.setElementAt({ 2 }, 300);

    NDArray<float64> scores({ 3 });
    scores.setElementAt({ 0 }, 85.5);
    scores.setElementAt({ 1 }, 92.3);
    scores.setElementAt({ 2 }, 78.9);

    std::vector<std::pair<std::string, NDArray<int32>>> int_arrays = { {"id", ids} };
    std::vector<std::pair<std::string, NDArray<float64>>> float_arrays = { {"score", scores} };

    auto arr1 = fromarrays(int_arrays);
    auto arr2 = fromarrays(float_arrays);

    // std::cout << "Array from int arrays:" << std::endl;
    //arr1.printArray();

    // std::cout << "Array from float arrays:" << std::endl;
    //arr2.printArray();

    auto id_check = arr1.getFieldValue<int32>({ 1 }, "id");
    auto score_check = arr2.getFieldValue<float64>({ 2 }, "score");

fromarrays (np_test_1_all.cpp:21655)

    ids.setElementAt({ 2 }, 300);

    NDArray<float64> scores({ 3 });
    scores.setElementAt({ 0 }, 85.5);
    scores.setElementAt({ 1 }, 92.3);
    scores.setElementAt({ 2 }, 78.9);

    std::vector<std::pair<std::string, NDArray<int32>>> int_arrays = { {"id", ids} };
    std::vector<std::pair<std::string, NDArray<float64>>> float_arrays = { {"score", scores} };

    auto arr1 = fromarrays(int_arrays);
    auto arr2 = fromarrays(float_arrays);

    // std::cout << "Array from int arrays:" << std::endl;
    //arr1.printArray();

    // std::cout << "Array from float arrays:" << std::endl;
    //arr2.printArray();

    auto id_check = arr1.getFieldValue<int32>({ 1 }, "id");
    auto score_check = arr2.getFieldValue<float64>({ 2 }, "score");

fromrecords (np_test_1_all.cpp:21622)

    record2.set("value", static_cast<float64>(20.7));
    record2.set("active", static_cast<bool_>(false));
    records.push_back(record2);

    StructuredRecord record3;
    record3.set("id", static_cast<int32>(3));
    record3.set("value", static_cast<float64>(15.3));
    record3.set("active", static_cast<bool_>(true));
    records.push_back(record3);

    auto arr = fromrecords(records);

    // std::cout << "Array created from records:" << std::endl;
    //arr.printArray();

    auto id_1 = arr.getFieldValue<int32>({ 1 }, "id");
    auto value_2 = arr.getFieldValue<float64>({ 2 }, "value");
    auto active_0 = arr.getFieldValue<bool_>({ 0 }, "active");

    // std::cout << "Verification:" << std::endl;
    // std::cout << "Record 1 ID: " << id_1 << " (expected: 2)" << std::endl;

fromrecords (np_test_1_all.cpp:21622)

    record2.set("value", static_cast<float64>(20.7));
    record2.set("active", static_cast<bool_>(false));
    records.push_back(record2);

    StructuredRecord record3;
    record3.set("id", static_cast<int32>(3));
    record3.set("value", static_cast<float64>(15.3));
    record3.set("active", static_cast<bool_>(true));
    records.push_back(record3);

    auto arr = fromrecords(records);

    // std::cout << "Array created from records:" << std::endl;
    //arr.printArray();

    auto id_1 = arr.getFieldValue<int32>({ 1 }, "id");
    auto value_2 = arr.getFieldValue<float64>({ 2 }, "value");
    auto active_0 = arr.getFieldValue<bool_>({ 0 }, "active");

    // std::cout << "Verification:" << std::endl;
    // std::cout << "Record 1 ID: " << id_1 << " (expected: 2)" << std::endl;

fromrecords (np_test_1_all.cpp:21622)

    record2.set("value", static_cast<float64>(20.7));
    record2.set("active", static_cast<bool_>(false));
    records.push_back(record2);

    StructuredRecord record3;
    record3.set("id", static_cast<int32>(3));
    record3.set("value", static_cast<float64>(15.3));
    record3.set("active", static_cast<bool_>(true));
    records.push_back(record3);

    auto arr = fromrecords(records);

    // std::cout << "Array created from records:" << std::endl;
    //arr.printArray();

    auto id_1 = arr.getFieldValue<int32>({ 1 }, "id");
    auto value_2 = arr.getFieldValue<float64>({ 2 }, "value");
    auto active_0 = arr.getFieldValue<bool_>({ 0 }, "active");

    // std::cout << "Verification:" << std::endl;
    // std::cout << "Record 1 ID: " << id_1 << " (expected: 2)" << std::endl;