Base Interest Rate: ${baseAnnualRate.toFixed(2)}%

`; const rateSteps = [-1.0, -0.5, -0.25, 0, 0.25, 0.5, 1.0]; // Percentage points from base rate let tableHTML = ``; let baseRateResults = null; const analysisResults = []; rateSteps.forEach(step => { let currentRate = baseAnnualRate + step; currentRate = Math.max(0.1, currentRate); // Ensure rate is at least minimally positive for calculation const results = calculateMonthlyPayment(loanAmount, currentRate, loanTermYears); analysisResults.push({ rate: currentRate, ...results }); if (step === 0) { baseRateResults = results; } }); analysisResults.forEach(res => { let monthlyPmtDiff = 0; let totalInterestDiff = 0; if (baseRateResults && res.rate !== baseAnnualRate) { monthlyPmtDiff = res.monthlyPayment - baseRateResults.monthlyPayment; totalInterestDiff = res.totalInterest - baseRateResults.totalInterest; } tableHTML += ``; }); tableHTML += `

Interest Rate (%)	Monthly P&I ($)	Total Interest Paid ($)	Total Payments ($)	Change in Monthly Pmt vs. Base ($)	Change in Total Interest vs. Base ($)
${res.rate.toFixed(2)}%	${res.monthlyPayment.toLocaleString(undefined, {minimumFractionDigits:2, maximumFractionDigits:2})}	${res.totalInterest.toLocaleString(undefined, {minimumFractionDigits:2, maximumFractionDigits:2})}	${res.totalPayment.toLocaleString(undefined, {minimumFractionDigits:2, maximumFractionDigits:2})}	${monthlyPmtDiff.toLocaleString(undefined, {minimumFractionDigits:2, maximumFractionDigits:2, signDisplay: 'always'})}	${totalInterestDiff.toLocaleString(undefined, {minimumFractionDigits:2, maximumFractionDigits:2, signDisplay: 'always'})}

`; sensitivityTableContainerEl.innerHTML = tableHTML; notesContainerEl.style.display = 'block'; downloadPdfBtn.style.display = 'block'; } // --- PDF Download --- downloadPdfBtn?.addEventListener('click', function () { const { jsPDF } = window.jspdf; const pdfOutputArea = document.getElementById('mrsaPdfOutputArea'); if (!pdfOutputArea || sensitivityTableContainerEl.innerHTML.includes("Please enter loan details")) { alert('Please analyze rates first before downloading PDF.'); return; } // Ensure notes are visible for PDF capture document.getElementById('mrsaNotesContainer').style.display = 'block'; document.getElementById('mrsaInputSummaryForPdf').style.display = 'block'; // Ensure summary is visible html2canvas(pdfOutputArea, { scale: 1.2, useCORS: true, backgroundColor: '#ffffff', windowWidth: pdfOutputArea.scrollWidth }) .then(canvas => { const imgData = canvas.toDataURL('image/jpeg', 0.9); const pdf = new jsPDF({ orientation: 'landscape', unit: 'pt', format: 'a4' }); // Landscape for wider table const pdfWidth = pdf.internal.pageSize.getWidth(); const pdfHeight = pdf.internal.pageSize.getHeight(); const margin = 30; let contentWidth = pdfWidth - 2 * margin; const canvasWidth = canvas.width; const canvasHeight = canvas.height; const ratio = canvasWidth / canvasHeight; let imgWidth = contentWidth; let imgHeight = imgWidth / ratio; if (imgHeight > pdfHeight - 2 * margin) { imgHeight = pdfHeight - 2 * margin; imgWidth = imgHeight * ratio; if (imgWidth > contentWidth) { imgWidth = contentWidth; imgHeight = imgWidth / ratio; } } const x = (pdfWidth - imgWidth) / 2; pdf.addImage(imgData, 'JPEG', x, margin, imgWidth, imgHeight, undefined, 'MEDIUM'); pdf.save('Mortgage_Rate_Sensitivity_Analysis.pdf'); }) .catch(err => { console.error("Error generating PDF:", err); alert("Error generating PDF. See console for details."); }); }); // --- Initial Setup --- switchTab('inputsTab'); });