mbloch/mapshaper

Features

• Coordinate Reference System Transformations - Transforms spatial data between different coordinate reference systems and projections to ensure correct map alignment.
• GeoJSON Processing - Provides a comprehensive tool for simplifying, transforming and editing vector geographic data in GeoJSON and TopoJSON formats.
• Polygonal Coverage Simplifiers - Provides topology-preserving simplification of polygonal data to reduce vertex complexity without creating gaps or overlaps.
• Topological Coverage Simplification - Reduces geometric complexity while preserving shared boundaries to prevent gaps and overlaps between adjacent features.
• Topological Deduplication - Stores shared boundaries only once in a topological structure to minimize redundancy and data size.
• Vector Geospatial Converters - Translates geospatial vector data between numerous formats including Shapefile, GeoJSON, TopoJSON, GeoPackage, and KML.
• Feature Attribute Management - Manipulates geospatial feature attributes using JavaScript expressions for filtering, calculation, and classification.
• Feature Filtering - Removes features from a layer based on a boolean expression or bounding box.
• Geographic Data Transformations - Converting spatial data between formats like Shapefile, GeoJSON, and TopoJSON while cleaning topology and repairing geometry errors.
• GeoJSON Data Ingestion - Parses GeoJSON files including nested documents or files exceeding memory limits.
• GeoJSON to TopoJSON Converters - Transforms spatial data into a topology-aware JSON format to reduce file size.
• Format Conversions - Translates spatial data between multiple vector formats such as Shapefile and GeoJSON to enable interoperability.
• TopoJSON Processing - Imports and exports topology data to reduce file size by storing shared boundaries once.
• Topology-Preserving Exports - Maintains shared boundaries between adjacent polygons during export to prevent data duplication.
• Vector Format Exports - Writes spatial data to formats including GeoJSON and TopoJSON with options for winding order and metadata.
• Coordinate Quantization - Decreases file size for web optimization by reducing coordinate precision to a fixed integer grid.
• Programmatic Spatial Execution - Runs geographic data editing commands via a script using filesystem-based processing or in-memory buffers.
• Spatial CLI Tooling - Executes spatial editing and conversion commands through a command-line interface for automation.
• Geospatial Vector Simplification - Reducing the number of vertices in geographic shapes to decrease file size while preserving visual detail and shared boundaries.
• Topology-Preserving Simplification - Applies identical simplification to boundaries shared between layers to prevent gaps and overlaps.
• Web Map Optimizations - Optimizes geographic vector data for web delivery through coordinate quantization and attribute filtering.
• Node.js Runtime Integration - Provides a Node.js library that allows spatial processing capabilities to be embedded directly into JavaScript applications and build pipelines.
• Node.js Spatial Data Libraries - Embedding geographic processing and coordinate transformation capabilities directly into JavaScript applications and build pipelines.
• Spatial Data Processing - Performing geometric operations such as buffering, clipping, and dissolving features to analyze or refine geographic datasets.
• Geometry Repair - Repairs abnormal geometry by removing overlaps, filling small gaps, and fixing self-intersections.
• Topology Preserving Processing - Preserves shared boundaries between adjacent polygons to prevent boundary duplication, gaps, and overlaps.
• Node.js Spatial Data Libraries - Provides a programmable interface for integrating geographic processing and coordinate transformation directly into JavaScript applications.
• Binary Vector Data Ingestion - Loads spatial datasets from binary formats for fast streaming and bounding-box queries.
• Computed Fields - Runs expressions on each feature to create or update attribute fields based on existing data.
• Data Joins - Attaches records from a source layer or file to a target layer using shared keys.
• Column Projections - Retains only a specified list of data fields in an attribute table.
• Dataset Element Deletion - Removes target layers, specific attribute fields, or geometry holes from a dataset.
• KML and GeoRSS Importers - Provides capabilities to import geographic data from KML and KMZ files.
• KML and KMZ Exports - Writes geographic data to XML-based KML or zipped KMZ formats for map viewers.
• Feature Erasers - Removes features or portions of features that fall inside a specified polygon area or bounding box.
• Web Asset Optimizations - Reduces GeoJSON file size by limiting coordinate precision and removing unnecessary attribute fields.
• GeoJSON to Vector Tile Conversion - Prepares datasets for tiling by cleaning topology, simplifying geometry, and exporting to GeoJSON.
• In-Memory Data Processors - Processes and transforms spatial datasets directly in system memory to avoid expensive disk I/O.
• GeoParquet Conversions - Reads and writes GeoParquet columnar files to exchange vector geometries and tabular attributes.
• Layer Consolidations - Merges multiple geographic data files into a single output file to simplify data management.
• Shapefile Importers - Imports vector data from Shapefile components and automatically detects companion files.
• Spatial Session Management - Maintains multiple independent collections of spatial features in a single stateful workspace.
• Tabular Data Import - Converts CSV and TSV files into attribute data or point layers by mapping coordinates.
• Tabular Data Managers - Reads tabular data and writes it to other geographic formats or plain-text delimiters.
• GeoPackage Processing - Imports and exports vector data using the SQLite-based GeoPackage format.
• Command Sequence Automation - Automates repetitive spatial processing by executing predefined sequences of commands from a text file.
• Text-Based Command Pipelines - Executes a sequence of operations defined in plain-text files using variable interpolation for automation.
• Interactive Consoles - Provides an interactive command-line shell for live manipulation of loaded geographic layers.
• JavaScript Logic Extensions - Enables the application of custom JavaScript logic to features for data manipulation, filtering, and sorting.
• Expression-Based Feature Styling - Assigns visual attributes like fill, stroke, and radius using JavaScript expressions evaluated per feature.
• Feature Color Assignments - Assigns colors to polygons using built-in schemes or random selection for visual classification.
• Geospatial Geometry Clipping - Trims geospatial geometries to remove portions falling outside a specified polygon area or bounding box.
• SVG Image Exports - Writes processed vector geographic data and styling into scalable vector graphics files for web or print output.
• Thematic Data Classifications - Assigns colors or values to features using quantile, equal-interval, or categorical classification methods.
• Map Visual Styling - Assigns colors, strokes, and labels to map features based on attributes to customize the visual appearance of the map.
• Expression Evaluators - Implements an engine that evaluates JavaScript-like logical expressions to calculate or modify feature attribute values.
• FlatGeobuf Processing - Processes binary vector data to allow for fast streaming reads and spatial indexing via FlatGeobuf.
• Geographic Buffer Generation - Generates buffer areas around points, lines, or polygons to define surrounding zones.
• Polygon Dissolving - Merges adjacent polygons into groups based on a specified data field.
• Spatial Partitioning Systems - Splits features into separate layers based on an attribute field or geographic grid.
• Memory Isolation - Executes heavy geographic computations in a separate process with an expanded heap to prevent main-thread crashes.
• Memory Buffering - Transforms datasets using in-memory buffers to optimize performance by avoiding intermediate disk writes.
• Large Dataset Optimizations - Handles geographic datasets exceeding several gigabytes using incremental reading and expanded memory.
• JavaScript Geospatial Libraries - Edits and processes Shapefile, GeoJSON, and TopoJSON files.
• Data conversion tools - Listed in the “Data conversion tools” section of the Awesome Arcgis Developers awesome list.
• Map and data exploration - Listed in the “Map and data exploration” section of the Awesome Arcgis Developers awesome list.

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