Reorganize Samples

The samples have become unwieldy when running them from a browser. In particular, the drop-down lists are fixed size with no scrolling, and many of them are now just too large. I have moved all the Calculation samples up a level, and broken several categories (Basic, Chart, DateTime, Engineering, Financial, and Reader) into several pieces.

Convert-Online (now found in the Engineering category) had a number of different problems which are now resolved. It is the only member with any significant code change.

samples/Engineering/GESTEP.php

@@ -0,0 +1,59 @@
+<?php
+
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
+require __DIR__ . '/../../Header.php';
+
+$category = 'Engineering';
+$functionName = 'GESTEP';
+$description = 'Returns 1 if number ≥ step; returns 0 (zero) otherwise';
+
+$helper->titles($category, $functionName, $description);
+
+// Create new PhpSpreadsheet object
+$spreadsheet = new Spreadsheet();
+$worksheet = $spreadsheet->getActiveSheet();
+
+// Add some data
+$testData = [
+    [5, 4],
+    [5, 5],
+    [4, 5],
+    [-4, -5],
+    [-5, -4],
+    [1],
+];
+$testDataCount = count($testData);
+
+$worksheet->fromArray($testData, null, 'A1', true);
+
+for ($row = 1; $row <= $testDataCount; ++$row) {
+    $worksheet->setCellValue('C' . $row, '=GESTEP(A' . $row . ',B' . $row . ')');
+}
+
+$comparison = [
+    0 => 'Value %d is less than step %d',
+    1 => 'Value %d is greater than or equal to step %d',
+];
+
+// Test the formulae
+for ($row = 1; $row <= $testDataCount; ++$row) {
+    /** @var int */
+    $aValue = $worksheet->getCell('A' . $row)->getValue();
+    /** @var int */
+    $bValue = $worksheet->getCell('B' . $row)->getValue();
+    /** @var int */
+    $cValue = $worksheet->getCell('C' . $row)->getCalculatedValue();
+    $helper->log(sprintf(
+        '(E%d): Compare value %d and step %d - Result is %d - %s',
+        $row,
+        $aValue,
+        $bValue,
+        $cValue,
+        sprintf(
+            $comparison[$cValue],
+            $aValue,
+            $bValue,
+        )
+    ));
+}