Scientific Data Analysis with LabPlot in Python: Signal Processing, Spectral Peak Fitting, Visualization, and Batch Automation

In this tutorial, we explore a LabPlot -inspired scientific data analysis workflow in Python while preserving the structure and terminology of LabPlot’s aspect tree, analysis kernels, plotting system, and project model. We build reusable components to import tabular data, compute descriptive statistics, smooth and differentiate signals, perform Fourier analysis and filtering, detect peaks, integrate curves, reduce data, and fit nonlinear models with detailed statistical diagnostics. We then apply these tools to a realistic spectroscopy example: removing periodic interference, identifying overlapping peaks, fitting a multi-Gaussian model, inspecting residuals, visualizing results through themed worksheets, exporting figures, and saving project data in LabPlot-compatible .lml-style files. Finally, we extend the same workflow to batch processing so we can analyze multiple temperature-dependent spectra and fit secondary trends across the resulting measurements.

We set up the Python environment, configure reproducibility, and establish the output directory for the tutorial. We recreate LabPlot’s core aspect-tree structure using projects, spreadsheets, columns, plot designations, and column modes. We also implement the AsciiFilter workflow to import structured text data into our LabPlot-style data model.

We implement the main numerical analysis kernels that let us smooth, differentiate, integrate, transform, filter, reduce, and inspect scientific signals. We add peak detection along with Gaussian and Lorentzian models for advanced curve analysis. We also build nonlinear fitting utilities that calculate parameter uncertainties, confidence intervals, goodness-of-fit statistics, and maximum-likelihood distribution fits.

We construct the visualization layer using curves, histograms, Cartesian plots, worksheets, themes, and reusable analysis-curve objects. We connect these plotting objects directly to our numerical operations so we can recalculate processed curves and fitted models programmatically. We also implement LabPlot-style project file loading and saving, including compressed .lml formats and spreadsheet reconstruction.

We generate a realistic noisy spectroscopy dataset containing a sloping baseline, overlapping Gaussian peaks, periodic interference, and random noise. We use Fourier analysis, band-reject filtering, smoothing, differentiation, and peak detection to isolate key spectral features before fitting. We then perform a constrained multi-Gaussian fit, integrate the recovered signal, reduce the data, calculate a Hilbert envelope, and statistically evaluate the fit residuals.

We organize the spectroscopy results into a themed worksheet containing the raw spectrum, fitted components, Fourier spectrum, detected peaks, and residual distribution. We export the complete visualization to PNG, PDF, and SVG formats so we have reusable graphical outputs. We also store our processed measurements and fitted parameters inside the project, save them in several .lml formats, and verify that the project data survives a complete round trip.