Configuration Reference

DifferentialLab reads configuration from .env in the project root.

Use .env.example as template.
Or use the in-app Configuration dialog (recommended).
On startup, values are validated against ENV_SCHEMA (src/config/env.py).
Invalid values are automatically replaced with defaults and logged.

How values are interpreted

bool: accepts true/false, 1/0, yes/no
int and float: parsed numerically with range checks where defined
str: non-empty; some keys enforce enumerated options

UI settings

Key	Default
`UI_BACKGROUND`	`#181818`
`UI_FOREGROUND`	`#CCCCCC`
`UI_BUTTON_BG`	`#1F1F1F`
`UI_BUTTON_WIDTH`	`14`
`UI_BUTTON_FG`	`lime green`
`UI_BUTTON_FG_CANCEL`	`red2`
`UI_BUTTON_FG_ACCENT2`	`yellow`
`UI_FONT_SIZE`	`16`
`UI_FONT_FAMILY`	`Bahnschrift`
`UI_PADDING`	`8`

Tooltip settings

Key	Default
`UI_TOOLTIP_DELAY_MS`	`500`
`UI_TOOLTIP_WRAPLENGTH`	`350`
`UI_TOOLTIP_PADX`	`8`
`UI_TOOLTIP_PADY`	`4`

Tooltip font size is derived automatically from UI_FONT_SIZE:

tooltip_size = max(6, round(UI_FONT_SIZE * 0.5))
There is no separate .env key for tooltip font size.

Plot settings

Layout and style

Key	Default
`PLOT_FIGSIZE_WIDTH`	`12`
`PLOT_FIGSIZE_HEIGHT`	`6`
`DPI`	`100`
`PLOT_SHOW_TITLE`	`true`
`PLOT_SHOW_GRID`	`true`
`PLOT_LINE_COLOR`	`royalblue`
`PLOT_LINE_WIDTH`	`1.5`
`PLOT_LINE_STYLE`	`-`
`PLOT_COLOR_SCHEME`	`Set1`

Markers

Key	Default
`PLOT_MARKER_FORMAT`	`o`
`PLOT_MARKER_SIZE`	`3`
`PLOT_MARKER_FACE_COLOR`	`crimson`
`PLOT_MARKER_EDGE_COLOR`	`crimson`

Phase-space and 3D/contour

Key	Default
`PLOT_PHASE_START_COLOR`	`green`
`PLOT_PHASE_END_COLOR`	`red`
`PLOT_PHASE_MARKER_SIZE`	`8`
`PLOT_SURFACE_CMAP`	`viridis`
`PLOT_CONTOUR_LEVELS`	`20`
`PLOT_GRID_ALPHA`	`0.3`
`PLOT_SURFACE_ALPHA`	`0.9`
`PLOT_COLORBAR_SHRINK`	`0.6`

Animation

Key	Default
`PLOT_ANIMATION_LINE_WIDTH`	`2.0`
`PLOT_VLINES_LINE_WIDTH`	`1.5`
`PLOT_VLINES_ALPHA`	`0.6`
`PLOT_ANIMATION_Y_MARGIN`	`0.1`
`ANIMATION_MAX_FPS`	`30`

Matplotlib font settings

Key	Default
`FONT_FAMILY`	`serif`
`FONT_TITLE_SIZE`	`xx-large`
`FONT_TITLE_WEIGHT`	`semibold`
`FONT_AXIS_SIZE`	`16`
`FONT_AXIS_STYLE`	`italic`
`FONT_TICK_SIZE`	`12`

Solver defaults

Key	Default
`SOLVER_MAX_STEP`	`0.0`
`SOLVER_RTOL`	`1e-8`
`SOLVER_ATOL`	`1e-10`
`SOLVER_NUM_POINTS`	`1000`

Supported methods in UI:

RK45
RK23
DOP853
Radau
BDF
LSODA

Logging and update checks

Key	Default
`LOG_LEVEL`	`INFO`
`LOG_FILE`	`differential_lab.log`
`LOG_CONSOLE`	`false`
`CHECK_UPDATES`	`true`
`UPDATE_CHECK_INTERVAL_DAYS`	`7`
`CHECK_UPDATES_FORCE`	`false`
`UPDATE_CHECK_URL`	`https://raw.githubusercontent.com/DOKOS-TAYOS/DifferentialLab/main/pyproject.toml`

Practical recommendations

Keep solver tolerances strict for stiff/nonlinear systems.
Lower SOLVER_NUM_POINTS for exploratory runs, increase for publication output.
Keep ANIMATION_MAX_FPS moderate (20-30) to avoid UI saturation.
Enable LOG_CONSOLE=true while debugging.

Source of truth

If this page and runtime behavior differ, runtime behavior is authoritative. The canonical schema lives in src/config/env.py (ENV_SCHEMA).