Cengraph Documentation & User Manual
Master high-performance spectroscopic processing, automated baseline fitting, vector canvas layout, and publication-ready 1200 DPI export with step-by-step guides.
โก Quick Topic Navigation
๐ Comprehensive Feature Manual (12 Guides)
01
๐ฅ๏ธ Workspace Overview & UI Navigation
Cengraph features an intuitive, high-density dark workspace engineered specifically for scientific spectroscopy. The interface consists of five core regions: Main Menu Bar, Data Explorer Panel (left), Vector Canvas Engine (center), Analysis & Style Inspector (right), and Real-Time Coordinates Toolbar (bottom).
- Launch Cengraph to load your persistent dark workspace preset (
#09090Bdeep obsidian background). - Toggle sidebars using Ctrl + B (Data Explorer) or Ctrl + Shift + I (Inspector) to maximize plot canvas area.
- Drag panel divider splitters to resize tree views, spectrum lists, and spectrum inspection properties.
- Use the Top Toolbar for quick access to peak inspection, pan/zoom, vector annotation, and figure export tools.
| Panel Name | Default Position | Function & Capability | Shortcut |
|---|---|---|---|
| Data Explorer | Left Sidebar | Displays imported spectrum files, color swatches, active layers, and multi-file series. | Ctrl + B |
| Vector Canvas | Center Workspace | 60 FPS GPU-accelerated canvas supporting single, stacked, and multi-artboard layouts. | Mouse Drag |
| Style Inspector | Right Sidebar | Adjusts line widths, stroke colors, axis tick marks, font sizes, and legend properties. | Ctrl + Shift + I |
| Status Toolbar | Bottom Footer | Displays real-time cursor coordinates (Wavenumber cmโปยน, Intensity a.u., Delta values). | Automatic |
02
๐ Importing Data & Spectral Grouping
Cengraph features a universal multi-vendor file reader that automatically parses raw spectroscopic files from Renishaw, Horiba, Thermo Fisher, Bruker, Ocean Optics, and custom laboratory instruments.
- Click File > Open Data or press Ctrl + O. Alternatively, drag and drop files onto the active canvas.
- Supported file extensions include .txt, .csv, .wdf (Renishaw), .labspec (Horiba), and .dat.
- In the Import Dialog, Cengraph automatically detects delimiters (Tab, Comma, Space, Semicolon) and header text offsets.
- Enable “Auto-Group by Prefix/Directory” to group multi-sample spectral series into unified color-coded datasets.
| Format Extension | Instrument Vendor | Header Auto-Detect | Multi-Column Support |
|---|---|---|---|
.txt / .csv |
Generic ASCII / Custom Lab | Automatic Line Detection | Multi-Y Spectrum Matrices |
.wdf |
Renishaw WiRE Spectroscopy | Native Binary Importer | Maps & Depth Profiles |
.labspec |
Horiba LabSpec 5 / 6 | Native Spectrum Archive | Multi-Laser Datasets |
.dat |
Ocean Optics / Bruker OPUS | ASCII Header Auto-Skip | Single & Multi-Trace |
03
๐พ Recent Projects & Native .cgph Sessions
Cengraph utilizes .cgph (Cengraph Project History), a native high-performance binary session archive that preserves raw data, baseline models, fitted peaks, canvas annotations, and custom theme presets without analytical precision loss.
- Save your workspace session by clicking File > Save Project (.cgph) or pressing Ctrl + S.
- Access recent projects directly from the Start Hub welcome screen or File > Recent Projects.
.cgpharchives store full 64-bit floating-point spectral data without truncation, preserving exact baseline and peak fits.- Automatic session locking protects against duplicate open windows and accidental file overwrites across desktop sessions.
| Feature Property | Saved Data & State | Precision Level |
|---|---|---|
| Raw & Processed Data | Raw spectra, subtracted baselines, smoothed curves, 2nd derivatives. | 64-bit Float (IEEE 754) |
| Canvas Layout | Multi-artboard positions, zoom levels, grid configurations. | Pixel-exact SVG state |
| Annotations | LaTeX text boxes, callout arrows, peak markers, shapes. | Vector Geometry |
.cgph session archive for seamless sharing with academic co-authors.
04
๐ Asymmetric Least Squares (AsLS) Baseline Correction
Background fluorescence and matrix interference are automatically removed using the Whittaker-Eilers Asymmetric Least Squares (AsLS) baseline estimation algorithm.
- Select target spectrum and open Analysis > Baseline Correction > AsLS or press Ctrl + Shift + B.
- Adjust Smoothness Penalty (ฮป): Higher values (e.g., 10โต – 10โท) generate stiffer, smoother baselines; lower values follow minor curvature.
- Adjust Asymmetry Factor (p): Values between 0.001 and 0.05 ensure baseline strictly bounds signal troughs without clipping peak tops.
- View real-time baseline preview superimposed on your spectrum before clicking Apply Subtraction.
| Parameter | Typical Range | Analytical Impact | Recommended Default |
|---|---|---|---|
Penalty (ฮป) |
10ยฒ to 10โน | Controls baseline curvature rigidity. Higher = smoother curve. | 10โต (Raman / FTIR) |
Asymmetry (p) |
0.0001 to 0.1 | Weights positive vs negative residuals. Lower = below peaks. | 0.01 |
Iterations |
10 to 50 | Maximum calculation cycles for mathematical convergence. | 20 cycles |
05
๐ Savitzky-Golay Noise Reduction & Derivatives
Savitzky-Golay filtering removes high-frequency experimental noise using localized polynomial least-squares regression, preserving peak amplitude, location, and spectral linewidths.
- Open Analysis > Noise Reduction > Savitzky-Golay or press Ctrl + Shift + G.
- Set Polynomial Order (k): Typically set to 2 or 3 to preserve peak shape without over-fitting noise.
- Set Frame Window Size (m): Must be an odd number (e.g., 7, 11, 15, 21 points). Broader windows increase smoothing strength.
- Select Derivative Order: 0 for standard smoothing, 1st Derivative for slope analysis, or 2nd Derivative for resolving overlapping doublet peaks.
| Setting | Valid Input | Effect on Signal | Default Value |
|---|---|---|---|
Polynomial Order (k) |
2, 3, 4, 5 | Higher orders fit sharp peak maxima more accurately. | 3 |
Window Length (m) |
Odd Integers (5-51) | Controls smoothing span. Larger window = stronger noise reduction. | 11 points |
Derivative Mode |
0, 1st, 2nd, 3rd | Calculates numerical derivatives for overlapping peak identification. | 0 (Smoothing) |
06
๐ Normalization Methods (SNV, Min-Max, Vector, Area)
Standardize intensity scales across varying sample thicknesses, laser powers, and acquisition integration times for accurate sample-to-sample comparison.
- Highlight single or multiple spectra in the Data Explorer list.
- Navigate to Analysis > Normalization or press Ctrl + Shift + N.
- Select from four scientific normalization algorithms:
- Min-Max [0, 1]: Rescales intensity so minimum is 0 and peak maximum is 1.0.
- Vector / Euclidean Norm: Divides intensity vector by its L2 norm (โโYยฒ = 1).
- SNV (Standard Normal Variate): Subtracts mean and divides by standard deviation (ฮผ=0, ฯ=1).
- Peak Area Normalization: Normalizes total integrated spectral area under curve to 1.0.
- Click Apply Normalization to update all selected plot traces simultaneously.
| Method | Mathematical Formula | Best Applied For |
|---|---|---|
| Min-Max [0, 1] | Y_norm = (Y - Y_min) / (Y_max - Y_min) |
Visual amplitude comparison of relative peak heights. |
| Vector (L2) | Y_norm = Y / โ(โ Yยฒ) |
Chemometric pre-treatment for PCA and classification models. |
| SNV | Y_norm = (Y - ฮผ) / ฯ |
Removing scatter artifacts in solid powders and rough surfaces. |
| Area Norm | Y_norm = Y / โซ Y dx |
Quantitative concentration and component fraction analysis. |
07
๐ Multi-Artboard Canvas & Stacked Multi-Panel Grids
Design publication-ready multi-figure layouts with independent or linked axes, stacked waterfall displays, and multi-panel comparison matrices within a single workspace.
- Click Canvas > Add Artboard or press Ctrl + Shift + A.
- Select layout arrangement: Single Artboard, Stacked Vertical (Waterfall), 2×2 Grid, or Multi-Panel Row.
- Drag spectra from the Data Explorer onto specific artboard subpanels.
- Toggle Synchronize X-Axis Zoom to navigate wavenumber ranges across all subpanels simultaneously.
| Layout Mode | Description | Axis Alignment | Max Subpanels |
|---|---|---|---|
| Single Artboard | Classic single plot view with overlay traces. | Shared X & Y | Unlimited Traces |
| Stacked Waterfall | Vertical Y-offset stacking of spectral series. | Shared X, Shifted Y | 50 Traces |
| 2×2 Matrix | Four-panel figure layout for comparative studies. | Linked or Independent | 4 Subpanels |
| Multi-Column Row | Side-by-side subplot row for multi-technique data. | Independent X & Y | 6 Subpanels |
08
๐ท๏ธ Draggable Legends & Interactive Canvas Labels
Cengraph legend boxes are fully interactive vector components that can be placed anywhere on the canvas with drag-and-drop precision and styled to match journal requirements.
- Click and drag the legend box anywhere across your active vector artboard.
- Double-click the legend to open the Legend Property Editor dialog.
- Customize legend title, sample label names, line stroke swatches, font size, and background opacity.
- Toggle legend border line, shadow blur, or transparent glassmorphic background fill.
| Property | Options | Journal Preset |
|---|---|---|
| Positioning | Free Drag-and-Drop, Top-Right, Top-Left, Outside Panel Margin | Outside Top-Right |
| Columns | 1, 2, 3, or 4 Horizontal Columns | Single Column Vertical |
| Frame Style | Solid White, Dark Glass, Borderless Transparent | Borderless Transparent |
| Font Family | Inter, JetBrains Mono, Times New Roman, Arial, Helvetica | Times New Roman / Inter |
09
โ๏ธ Smart Vector Annotations & LaTeX Math Rendering
Add publication-quality callouts, peak indicators, chemical formulas, structural arrows, and LaTeX math typography directly onto the vector plot layer.
- Select an annotation tool from the top toolbar: Peak Callout, Vertical Marker Line, Arrow, Rectangle, or LaTeX Text.
- Click on a specific spectral peak to anchor the annotation directly to data coordinates (Wavenumber, Intensity).
- Double-click text box to enter labels with integrated LaTeX formatting (e.g.,
$\nu_{1}(A_{1g})$or$\text{cm}^{-1}$). - Customize line dash styles (Solid, Dashed, Dotted), arrow head styles, and color accents in the Style Inspector.
| Tool Name | Icon / Shortcut | Coordinate Anchor Type | LaTeX Math Capable |
|---|---|---|---|
| Text Label | T |
Data Anchor (cmโปยน, Intensity) | Yes (Full MathJax/LaTeX) |
| Peak Marker Line | L |
X-Axis Wavenumber Lock | Yes (Peak Value Tag) |
| Callout Arrow | A |
2-Point Vector Line | Yes (Callout Text) |
| Region Shade Box | R |
X1 to X2 Range Box | Yes (Band Name Tag) |
10
๐ฏ Live Peak Analyzer & Deconvolution Engine
Fit complex overlapping spectral envelopes using non-linear least-squares peak deconvolution with Gaussian, Lorentzian, and Voigt band profiles.
- Highlight region of interest on your spectrum using Shift + Click & Drag.
- Open Analysis > Peak Analyzer / Deconvolution or press Ctrl + Shift + P.
- Click Auto-Detect Peaks or double-click peak maxima to position initial peak seeds.
- Choose line shape profile (Gaussian, Lorentzian, or Pseudo-Voigt) and click Run Deconvolution.
| Profile Function | Physical Basis | Calculated Output Parameters |
|---|---|---|
| Gaussian Band | Inhomogeneous broadening (Doppler, instrumental resolution) | Center (cmโปยน), Peak Height, FWHM, Area % |
| Lorentzian Band | Homogeneous broadening (Finite state lifetime) | Center (cmโปยน), Peak Height, FWHM, Area % |
| Pseudo-Voigt | Combined Gaussian-Lorentzian convolution | Center (cmโปยน), Height, FWHM, Area %, Shape (ฮท) |
11
๐ผ๏ธ Exporting Publication Figures (1200 DPI, SVG, PDF)
Generate ultra-high resolution vector and raster figures customized to target journal publisher standards (Nature, ACS, RSC, Elsevier, Wiley).
- Click File > Export Figure or press Ctrl + E.
- Select output format:
- SVG: Scalable Vector Graphics for Adobe Illustrator / Inkscape editing.
- PDF: Vector PDF with embedded fonts for direct manuscript submission.
- PNG / TIFF: High-density raster images at 300, 600, or 1200 DPI.
- Choose publication physical dimension preset: Single Column (89 mm) or Double Column (183 mm).
- Click Export Figure to render your publication-ready graphic instantly.
| Export Format | Resolution / DPI | Color Space | Target Publisher |
|---|---|---|---|
| SVG (Vector) | Infinite Scalable | sRGB / CMYK | Adobe Illustrator / Inkscape |
| PDF (Vector) | Vector Geometry | Embedded Fonts | Direct Manuscript Submission |
| PNG (Raster) | 300, 600, 1200 DPI | RGB Alpha Trans. | Nature, ACS, RSC, Elsevier |
12
โจ๏ธ Multi-Tab Session Management & Keyboard Shortcuts
Maximize laboratory workflow speed with multi-tab project navigation and comprehensive zero-mouse hotkey shortcuts.
- Work on multiple active spectral projects simultaneously across tabbed project views.
- Switch tabs using Ctrl + Tab or Ctrl + Shift + Tab.
- Memorize core hotkeys for data loading, processing, baseline fitting, and figure export.
- Customize shortcut mappings via Preferences > Keyboard Shortcuts.
| Action Command | Shortcut Key | Context Scope |
|---|---|---|
| Open Data File | Ctrl + O |
Global Workspace |
| Save Project Session | Ctrl + S |
Active Session |
| Export Publication Figure | Ctrl + E |
Active Canvas |
| AsLS Baseline Panel | Ctrl + Shift + B |
Spectral Analysis |
| Savitzky-Golay Panel | Ctrl + Shift + G |
Spectral Processing |
| Normalization Panel | Ctrl + Shift + N |
Data Matrix |
| Live Peak Analyzer | Ctrl + Shift + P |
Deconvolution |
| Toggle Sidebars | Ctrl + B |
UI Layout |
| Reset Zoom / Fit Canvas | Ctrl + 0 |
Vector Canvas |
| Fullscreen Mode | F11 |
Display Mode |