Method sampleValues

src/frontend/spreadsheet/SampleValuesDialog.cpp:176–233

};

void SampleValuesDialog::sampleValues() const {
	WAIT_CURSOR;
	const auto method = static_cast<Method>(ui.cbMethod->currentIndex());

	QVector<int> rows;
	switch (method) {
	case Method::Periodic: {
		int period = ui.sbValue->value();
		int count = std::floor(m_spreadsheet->rowCount() / period);
		for (int i = 0; i < count; ++i)
			rows << period * (i + 1) - 1;
		break;
	}
	case Method::Random: {
		// create a generator chosen by the environment variable GSL_RNG_TYPE
		gsl_rng_env_setup();
		const gsl_rng_type* T = gsl_rng_default;
		gsl_rng* r = gsl_rng_alloc(T);
		gsl_rng_set(r, QDateTime::currentMSecsSinceEpoch());

		int sampleSize = ui.sbValue->value();
		int a = 0;
		int b = m_spreadsheet->rowCount() - 1;
		for (int i = 0; i < sampleSize; ++i)
			rows << (int)round(gsl_ran_flat(r, a, b));
		break;
	}
	}

	m_spreadsheet->beginMacro(i18n("%1: sample values", m_spreadsheet->name()));

	// create target spreadsheet
	auto* targetSpreadsheet = new Spreadsheet(i18n("Sample of %1", m_spreadsheet->name()));
	targetSpreadsheet->setColumnCount(m_columns.count());
	targetSpreadsheet->setRowCount(rows.count());

	int index = 0;
	const auto& targetColumns = targetSpreadsheet->children<Column>();
	for (auto* source : m_columns) {
		auto* target = targetColumns.at(index);
		target->setName(source->name());
		target->setColumnMode(source->columnMode());
		++index;
	}

	for (int i = 0; i < m_columns.count(); ++i) {
		auto* task = new SampleValuesTask(m_columns.at(i), targetColumns.at(i), rows);
		QThreadPool::globalInstance()->start(task);
	}

	// wait until all columns were processed
	QThreadPool::globalInstance()->waitForDone();

	m_spreadsheet->parentAspect()->addChild(targetSpreadsheet);

	m_spreadsheet->endMacro();
	RESET_CURSOR;
}