Design Of An Automated Polyhouse Mist Cooling System Based On Vapor Pressure Deficit Vpd Calculations

Then, open your browser to http://localhost:3000 (or the custom port you specified). You can adjust temperature and humidity ranges using sliders and immediately see the updated VPD chart.

import { calculateVpd, VpdStage, generateChartData, renderVpdChart, setVpdThresholds } from 'vpd-calculator';

// 1. Calculate VPD for specific conditions const result = calculateVpd(25, 60, VpdStage.Veg); console.log( VPD: ${result.vpd} kPa, Range: ${result.range} ); // Output: VPD: 1.268 kPa, Range: optimal

// 2. Generate data for a chart const chartOptions = { stage: VpdStage.Flower, tempMinC: 20, tempMaxC: 30, tempStepC: 1, humidityMin: 40, humidityMax: 70, humidityStep: 5, }; const chartData = generateChartData(chartOptions); console.log( Generated ${chartData.points.length} data points for the chart. );

// 3. Render a chart to a PNG buffer (Node.js/Bun environment) async function createChartImage { const imageBuffer = await renderVpdChart(chartData, { stage: VpdStage.Flower, width: 800, height: 600 }); // imageBuffer is a Node.js Buffer containing PNG data // You can save it to a file, send it as an HTTP response, etc. // require('fs').writeFileSync('vpd_chart.png', imageBuffer); console.log('Chart image generated.'); } createChartImage;

// 4. Customize VPD thresholds setVpdThresholds(VpdStage.Propagation, { low: 0.7, high: 0.9 }); const customResult = calculateVpd(22, 75, VpdStage.Propagation); console.log( Custom VPD for Propagation: ${customResult.vpd} kPa, Range: ${customResult.range} );

Calculates the Vapor Pressure Deficit (VPD) in kilopascals (kPa) for given temperature and humidity, and classifies it based on the specified growth stage's thresholds.

Classifies a given VPD value ('low', 'optimal', 'high') based on the thresholds for the specified growth stage.

Retrieves the active VPD thresholds (low and high kPa values) for a given growth stage. Returns custom thresholds if set, otherwise defaults.

Sets custom VPD thresholds for a specific growth stage, overriding the defaults. These will be used in subsequent calculations and classifications.

Resets custom VPD thresholds for a specific stage to its default values. If no stage is provided, all custom thresholds are reset.

Generates a matrix of VPD data points across specified temperature and humidity ranges, suitable for charting.

(Node.js/Bun only) Renders the generated ChartData into a PNG image buffer using chart.js and canvas .