Getting started#

GraphX converts positions on a graph image into numerical data. Start with a clear source image, calibrate its axes, then add points manually or trace a curve.

1. Open an image#

On the welcome screen, select Open an image or drop a JPG, PNG, WebP, or GIF into the drop area. GraphX processes the image locally in your browser. You can also begin from Open project or load the bundled sample project from Instructions.

2. Calibrate the graph#

Calibration maps positions in the image to values on the graph. For screenshots, scans, and exported plots, Fast calibration is usually the simplest option. Use Perspective calibration for a photographed or visibly perspective-distorted plot. Each axis can be linear or logarithmic; see Logarithmic axes.

Calibration overview explains how to choose the method without repeating every calibration step here.

3. Add data#

Choose Add/edit points to place points manually and correct existing ones. Choose Trace curve to select a seed on a distinguishable curve, review the preview, and add a chosen number of points. Both approaches add normal editable points to the active dataset.

4. Organise the result#

Use separate Datasets for separate curves or series. Each dataset has its own name, colour, ordered points, export inclusion, and numerical display/export precision.

5. Optional trendline#

The Trendlines section can fit a Linear, Polynomial, Logarithmic, Exponential, or Power model to a dataset. Use this when a fitted relationship is useful alongside the measured points.

6. Export or save#

Export creates CSV data, a PDF report, or a JPEG image. Copy data in the Data points drawer copies the active dataset as tab-separated values. Save project creates an editable .graphx project containing the image and current working state; it is different from exporting a result. Notes can keep project-specific context with that project.

For the usual end-to-end sequence, continue to Basic workflow. For a map of the interface, see Interface overview.