log('Returns the effective annual interest rate for a given nominal interest rate and number of'); $helper->log('compounding periods per year.'); // Create new PhpSpreadsheet object $spreadsheet = new Spreadsheet(); $worksheet = $spreadsheet->getActiveSheet(); // Add some data $arguments = [ [0.10, 4], [0.10, 2], [0.025, 2], ]; $worksheet->fromArray($arguments, null, 'A1'); $worksheet->getStyle('B1:B3')->getNumberFormat()->setFormatCode('0.00%'); // Now the formula for ($row = 1; $row <= 3; ++$row) { $worksheet->setCellValue("C{$row}", "=EFFECT(A{$row}, B{$row})"); $worksheet->getStyle("C{$row}")->getNumberFormat()->setFormatCode('0.00%'); $helper->log($worksheet->getCell("C{$row}")->getValue()); $helper->log('EFFECT() Result is ' . $worksheet->getCell("C{$row}")->getFormattedValue()); }