Crate map2fig 

HEALPix Plotter

A Rust library for rendering HEALPix celestial maps in multiple projections (Mollweide, Hammer, Gnomonic).

Overview

This library reads astronomical data from FITS files containing HEALPix sky maps and generates publication-quality visualizations in PDF and PNG formats. Key features include:

• Multiple projections: Mollweide, Hammer, and Gnomonic
• 80+ colormaps: matplotlib and custom colormaps
• Data scaling: linear, logarithmic, symlog, asinh, and histogram equalization
• HEALPix support: RING and NEST ordering, sparse and dense maps
• Output formats: High-quality PDF via Cairo and PNG via image crate
• Customization: full control over colors, scale, gamma, graticules, and more

Quick Start

use map2fig::plot::plot_mollweide_auto;
use map2fig::params::MollweideParams;

let params = MollweideParams {
    fits_file: "map.fits".to_string(),
    output_file: "map.pdf".to_string(),
    ..Default::default()
};
plot_mollweide_auto(params);

Main Plotting Functions

• plot_mollweide_png - Render Mollweide projection to PNG
• plot_mollweide_pdf - Render Mollweide projection to PDF
• plot_mollweide_auto - Render Mollweide with automatic format selection
• plot_gnomonic_png - Render Gnomonic projection to PNG
• plot_gnomonic_pdf - Render Gnomonic projection to PDF
• plot_gnomonic_auto - Render Gnomonic with automatic format selection
• plot_hammer_png - Render Hammer projection to PNG
• plot_hammer_pdf - Render Hammer projection to PDF
• plot_hammer_auto - Render Hammer with automatic format selection

Core Types

• scale::Scale - Data scaling method (linear, log, symlog, asinh, histogram)
• NegMode - Handling strategy for negative/masked values
• Colormap - Color palette for mapping data values to colors
• colormap::get_colormap - Get a colormap by name
• healpix::HealpixMeta - HEALPix metadata from FITS file
• PixelMask - Boolean mask for pixel filtering

Data Processing

• healpix::read_healpix_meta - Read HEALPix metadata from FITS
• fits::read_healpix_column - Read HEALPix data from FITS file
• healpix::downgrade_healpix_map - Resample HEALPix map to different resolution
• scale::validate_scale_config - Validate scaling parameters

Re-exports

pub use cli::Args;

pub use cli::PlotConfig;

pub use colormap::Colormap;

pub use colormap::available_colormaps;

pub use colormap::get_colormap;

pub use fits::read_healpix_column;

pub use fits::read_healpix_column_cached;

pub use mask::PixelMask;

pub use pdf_optimize::PdfOptimizationConfig;

pub use pdf_optimize::estimate_pdf_complexity;

pub use plot::plot_gnomonic_auto;

pub use plot::plot_gnomonic_pdf;

pub use plot::plot_gnomonic_png;

pub use plot::plot_hammer_auto;

pub use plot::plot_hammer_pdf;

pub use plot::plot_hammer_png;

pub use plot::plot_mollweide_auto;

pub use plot::plot_mollweide_pdf;

pub use plot::plot_mollweide_png;

pub use scale::validate_scale_config;

pub use constants::*;

Modules

benchmark

PDF Rendering Benchmarks and Performance Analysis

cli

cli_builder

CLI argument builder utilities for constructing plot parameters.

colorbar

colormap

constants

diagnostics

Performance diagnostics and profiling module.

executor

Plot execution module - handles projection selection and rendering.

fits

FITS file reading and data extraction.

gnomonic

gnomonic_graticule

Graticule rendering for gnomonic projections

graticule

hammer

healpix

HEALPix coordinate system and data sampling utilities.

latex

LaTeX-like text rendering for mathematical expressions

latex_render

layout

mask

mmap_reader

Memory-mapped FITS file reader

mollweide

params

Parameter bundling structs for plot functions.

pdf_optimize

pipeline

plot

projection

render

rotation

Coordinate rotations for astronomy.

scale

Data scaling and value normalization for visualization.

setup

Setup module - handles application initialization.

simd

SIMD vectorization module for high-performance batch operations.

Structs

BatchedCairoImageSink

Batched Cairo pixel sink - groups pixels by color to reduce fill() calls.

CairoRasterSink

Sink for rendering pixels to a Cairo drawing context.

PngSink

Sink for rendering pixels directly to an in-memory PNG image buffer.

RgbaArg

RGBA color specified as comma-separated integers 0–255.

Enums

NegMode

Strategy for handling negative, masked, or invalid pixel values in HEALPix maps.

PixelValue

Pixel value classification during data-to-color mapping.

Traits

PixelSink

Trait for pixel rendering backends.

Functions

generate_index_map

Generate a simple index map for testing.