some of the fixes #2 #5

Author: allixender

website/docs/ecosystem/dggrid.md

@@ -41,6 +41,7 @@ A minimal metafile for generating IGEO7 cells looks like:
 ```
 dggrid_operation  GENERATE_GRID
 dggs_type         IGEO7
+dggs_vert0_lon     11.20
 dggs_res_spec     9
 clip_subset_type  WHOLE_EARTH
 cell_output_type  GEOJSON
@@ -62,7 +63,7 @@ DGGRID supports two names for the same underlying grid:
 | `IGEO7` | Z7 / Z7_STRING | Recommended; uses Z7 indexing natively |
 | `ISEA7H` | SEQNUM, Q2DI, etc. | Same grid; older addressing schemes |
 
-Always use `IGEO7` with `output_address_type="Z7_STRING"` for new work.
+Always use `IGEO7` with `output_address_type="Z7_STRING"` for new work (`HIERNDX` required from latest DGRID).
 
 ## ISEA Orientation
 
@@ -74,7 +75,20 @@ dggs_vert0_lat     58.2825255885
 dggs_vert0_azimuth  0.0
 ```
 
-This is the default and does not need to be specified explicitly when using dggrid4py.
+This is the default, but `dggs_vert0_lon     11.20` needs to be specified explicitly when using dggrid4py:
+
+```
+dggs_vert0_lon     11.20
+dggs_vert0_lat     58.2825255885
+dggs_vert0_azimuth  0.0
+```
+
+
+## TODO Authalic conversion
+
+dggrid4py (and Julia DggridRunner) has functions to translate/convert between the default spherical coordinates of DGGRID and now widely adopted ellipsoidal DGGS coordinates.
+
+DGGAL does that authomatically for its ISEA7H_Z7 grid adaptation of IGEO7.
 
 ## Further Reading
 

website/docs/highlights/equal-area.md

@@ -20,9 +20,9 @@ With H3's gnomonic projection, cells near icosahedral face edges are up to **50%
 
 | System | Projection | Cell area variation |
 |---|---|:---:|
-| **IGEO7** | ISEA (equal area) | **0%** |
+| **IGEO7** | ISEA (equal area) | **<0.1%** |
 | H3 | Gnomonic | up to ±50% |
-| S2 | Cube face projection | up to ±30% |
+| S2 | Cube face projection | up to ±50% |
 
 These are not edge-case outliers. H3's ±50% variation is a systematic property of its projection — every cell near an icosahedral face edge is significantly smaller than a face-centre cell at the same resolution.
 

website/docs/highlights/use-cases.md

@@ -12,18 +12,6 @@ IGEO7 is particularly well suited to applications where **equal area matters** a
 
 **Biodiversity and species distribution modelling** requires area-accurate grid cells so that species richness per unit area is comparable across regions. IGEO7's equal-area guarantee means a cell at resolution 9 in Estonia covers the same 1.264 km² as a cell in Brazil.
 
-```python
-# Index species observations to IGEO7 resolution 9
-gdf_obs = dggrid.cells_for_geo_points(
-    geodf_points_wgs84=observations,
-    cell_ids_only=True,
-    dggs_type="IGEO7",
-    resolution=9,
-)
-# Count per cell — directly comparable across the globe
-counts = gdf_obs.groupby("name").size()
-```
-
 **Land cover and habitat area** — aggregate raster data (Sentinel-2, Copernicus Land Cover) into IGEO7 cells for consistent area-weighted statistics. Resolution 14 (~9.8 m) matches Sentinel-2's 10 m native resolution.
 
 ## Earth Observation Data Cubes
@@ -43,31 +31,22 @@ The uniform cell size makes spatial aggregation and resampling mathematically co
 
 ## Hydrology and Water Resources
 
-Stream networks and catchment delineation benefit from IGEO7's multi-resolution hierarchy. Resolutions 8–10 (~3–1.3 km) match typical hydrological modelling scales; resolution 12 (~68 m) suits fine-scale flow routing.
+Stream networks and catchment delineation benefit from IGEO7's multi-resolution hierarchy. Resolutions 8-10 (~3-1.3 km) match typical hydrological modelling scales; resolution 12 (~68 m) suits fine-scale flow routing.
 
 Because cells are equal area, runoff volumes computed per cell are directly summable up the hierarchy without correction factors.
 
+With the Z7 indexing, it is a very fast operation to query the neighbours, and the neighbours are alsway in a predictable order.
+
 ## Urban Analytics and Planning
 
 Resolution 11 (~181 m) and 12 (~68 m) provide natural scales for neighbourhood-level urban analysis — matching typical census block sizes and street-grid granularity. The hexagonal topology (all 6 neighbours equidistant) avoids the directional bias of square grids.
 
-```python
-# Generate IGEO7 grid over a city at 181m resolution
-city_bbox = shapely.geometry.box(24.5, 59.3, 25.2, 59.6)  # Tallinn
-
-grid = dggrid.grid_cell_polygons_for_extent(
-    dggs_type="IGEO7",
-    resolution=11,
-    clip_geom=city_bbox,
-    output_address_type="Z7_STRING",
-)
-```
 
 ## OGC API DGGS Services
 
-**pydggsapi** implements the [OGC API – DGGS](https://ogcapi.ogc.org/dggs/) standard with IGEO7 as a supported reference system. This allows IGEO7-indexed data to be served via standardised REST endpoints, consumable by any OGC-compliant client.
+**pydggsapi** implements the [OGC API - DGGS](https://ogcapi.ogc.org/dggs/) standard with IGEO7 as a supported reference system. This allows IGEO7-indexed data to be served via standardised REST endpoints, consumable by any OGC-compliant client.
 
-Supported backends: Clickhouse (columnar analytics), Zarr (cloud-native arrays), Parquet.
+Supported backends: Clickhouse (columnar analytics), Zarr (cloud-native arrays), Parquet (via DuckDB).
 
 See [pydggsapi ecosystem page](../ecosystem/pydggsapi).
 
@@ -79,7 +58,7 @@ See [pydggsapi ecosystem page](../ecosystem/pydggsapi).
 | Density maps (events/km²) | Biased | Equal area eliminates bias |
 | Area statistics (land cover) | Biased | Equal area eliminates bias |
 | Scientific reproducibility | Varies by location | Consistent everywhere |
-| Very fine resolution (< 1 m) | No (max res 15 ~1 m²) | Res 18–20 reach centimetres |
+| Very fine resolution (< 1 m) | No (max res 15 ~1 m²) | Res 18-20 reach centimetres |
 | Cloud-native data cubes | Limited | Xarray-XDGGS integration |
 | OGC API DGGS compliance | Partial | pydggsapi native support |
 

website/docs/installation.md

@@ -6,7 +6,7 @@ title: Installation
 
 # Installation
 
-IGEO7 is implemented in **DGGRID** (the core C++ engine) and accessed via the **dggrid4py** Python wrapper. You need both.
+IGEO7 is implemented in **DGGRID** (the core C++ engine) and accessed via the **dggrid4py** Python wrapper.
 
 ## 1. Install DGGRID
 
@@ -16,6 +16,19 @@ DGGRID is a C++ command-line tool. You need a compiled binary on your system.
 
 Download a pre-built binary from the [DGGRID releases page](https://github.com/sahrk/DGGRID/releases).
 
+### With conda / mamba (or even Julia)
+
+or install from conda-forge (via Pixi or micomamba)
+
+```bash
+conda install -c conda-forge dggrid
+```
+
+```julia
+using Pkg; Pkg.add("DggridRunners")
+```
+
+
 ### Build from source
 
 ```bash
@@ -37,7 +50,7 @@ dggrid --version
 
 ### Setting the path
 
-dggrid4py locates the DGGRID binary via the `DGGRID_PATH` environment variable or an explicit path in the API call:
+dggrid4py requires the DGGRID binary via the `DGGRID_PATH` environment variable or an explicit path in the API call:
 
 ```bash
 export DGGRID_PATH=/usr/local/bin/dggrid
@@ -47,17 +60,12 @@ export DGGRID_PATH=/usr/local/bin/dggrid
 
 dggrid4py is the Python wrapper that drives DGGRID programmatically.
 
-### With pip
+### With pip (or uv or pixi)
 
 ```bash
 pip install dggrid4py
 ```
 
-### With conda / mamba
-
-```bash
-conda install -c conda-forge dggrid4py
-```
 
 ### Dependencies
 
@@ -82,7 +90,7 @@ pip install dggal
 
 ```python
 import os
-from dggrid4py import DGGRIDv7
+from dggrid4py import DGGRIDv8
 
 dggrid = DGGRIDv7(
     executable=os.environ.get("DGGRID_PATH", "/usr/local/bin/dggrid"),

website/docs/intro.md

@@ -8,7 +8,7 @@ title: Introduction
 
 IGEO7 is a **hierarchically indexed hexagonal equal-area Discrete Global Grid System (DGGS)** with the **Z7** indexing system.
 
-It is the **equal-area alternative to H3** — sharing the aperture 7 hexagonal hierarchy and 64-bit integer indexing of H3, but using the **ISEA (Icosahedral Snyder Equal Area)** projection instead of H3's gnomonic projection. This guarantees all cells have truly equal area (H3 cells vary by up to ±50%).
+It is the **equal-area alternative to H3**, sharing the aperture 7 hexagonal hierarchy and a comparable 64-bit integer indexing of H3, but using the **ISEA (Icosahedral Snyder Equal Area)** projection instead of H3's gnomonic projection. This guarantees all cells have truly equal area (H3 cells vary by up to ±50%).
 
 :::tip Key paper
 IGEO7 is described in: Kmoch, A., Sahr, K., Chan, W.T., Uuemaa, E. (2025). *IGEO7: A new hierarchically indexed hexagonal equal-area discrete global grid system.* AGILE: GIScience Series, 6, 32. [https://doi.org/10.5194/agile-giss-6-32-2025](https://doi.org/10.5194/agile-giss-6-32-2025)
@@ -19,18 +19,18 @@ IGEO7 is described in: Kmoch, A., Sahr, K., Chan, W.T., Uuemaa, E. (2025). *IGEO
 A **Discrete Global Grid System** partitions the entire surface of the Earth into a finite set of non-overlapping cells, providing a framework for spatial indexing, aggregation, and analysis at any resolution.
 
 IGEO7 is implemented in:
-- **DGGRID** (C++) — the core engine
-- **DGGAL** — supports ISEA7H_Z7
-- **dggrid4py** — Python wrapper
-- **pydggsapi** — OGC API DGGS server
+- **DGGRID** (C++) — the original reference implementation of ISEA7H and Z7
+- **DGGAL** — supports IGEO7 via ISEA7H_Z7
+- **dggrid4py** — Python wrapper for DGGRID, can take care of correct definitions
+- **pydggsapi** — OGC API DGGS server that supports both dggrid4py and dggal
 
 ## Core Properties
 
 | Property | IGEO7 | H3 |
 |---|---|---|
 | Projection | ISEA (equal area) | Gnomonic |
 | Cell shape | Hexagons + 12 pentagons | Hexagons + 12 pentagons |
-| Aperture | Pure 7 | Mixed (4→3→7) |
+| Aperture | Pure 7 | Custom toplevel, then 7 |
 | Resolutions | 0–20 (21 levels) | 0–15 (16 levels) |
 | Base cells | 12 | 122 |
 | Index size | 64-bit integer | 64-bit integer |

website/docs/quickstart.md

@@ -8,6 +8,10 @@ title: Quickstart
 
 From zero to working IGEO7 cells in Python using **dggrid4py**.
 
+TODO:
+- Apply authalic conversion in dggrid4py
+- Provide parameter 11.2 
+
 ## Setup
 
 ```python

website/docs/reference/restable.md

@@ -1,12 +1,12 @@
 ---
 id: restable
 sidebar_position: 1
-title: Resolution Table
+title: Refinement Level Table
 ---
 
 # Resolution Table
 
-IGEO7 has **21 resolution levels** (0–20). At every resolution, the grid contains exactly **12 pentagons** (at icosahedron vertices) and all remaining cells are hexagons.
+IGEO7 has **21 resolution levels** (0–20). At every refinement level, the grid contains exactly **12 pentagons** (at icosahedron vertices) and all remaining cells are hexagons. Level 0 is only the 12 base pentagons.
 
 **CLS** (Characteristic Length Scale) is the diameter of a circle with the same area as a cell — the most intuitive way to relate IGEO7 resolutions to traditional raster pixel sizes.
 
@@ -100,6 +100,7 @@ dggrid = DGGRIDv7(
     silent=True,
 )
 
-df = dggrid.grid_stats_table("IGEO7", 20)
+# yes, ISEA7H, IGEO7 is not recognized as a grid for resolutions in itself :-)
+df = dggrid.grid_stats_table("ISEA7H", 20)
 print(df.to_string())
 ```

website/src/components/HomepageFeatures/index.js

@@ -8,9 +8,9 @@ const FeatureList = [
     icon: "⬡",
     description: (
       <>
-        Every cell has the same area at each resolution — guaranteed by the ISEA
+        Every cell has the same area at each resolution, based on the ISEA
         (Icosahedral Snyder Equal Area) projection. No ±50% distortions like in
-        gnomonic-based systems.
+        H3, S2, GeoHash, or Mercator-based systems.
       </>
     ),
   },
@@ -20,7 +20,7 @@ const FeatureList = [
     description: (
       <>
         A single 64-bit integer encodes resolution, base cell, and full
-        hierarchical path. Parent–child relationships are simple bit operations.
+        hierarchical path. Parent-child relationships are simple bit operations.
         Compatible with H3-style workflows.
       </>
     ),