gatilegrid 0.2.0

Popular tile grids and grids API for web mapping applications

gatilegrid

Geoadmin custom tile grid for web mapping applications

gatilegrid is compatible with python 2.7, 3.5, 3.6 and 3.7

Installation

$ pip install gatilegrid

Usage

Several tile grids are supported, namely 21781, 2056, 3857 and 4326. Here is an exemple using 21781. For 4326, an additional parameter is available (tmsCompatible=True).

from gatilegrid import getTileGrid
from gatilegrid import GeoadminTileGridLV03 as GeoadminTileGrid

zoom = 18
tileCol = 6
tileRow = 7

# Get and initialize the grid (top-left and bottom-left are availble)
gagrid = getTileGrid(21781)(originCorner='top-left')
# With extent constraint
offset = 100000
gagridExtent = GeoadminTileGrid(extent=[gagrid.MINX + offset, gagrid.MINY + offset,
                                        gagrid.MAXX - offset, gagrid.MAXY - offset])

bounds = [xmin, ymin, xmax, ymax] = gagrid.tileBounds(zoom, tileCol, tileRow)
print(bounds)
>>> [496800.0, 247600.0, 509600.0, 260400.0]
print(gagrid.tileAddressTemplate)
>>> {zoom}/{tileCol}/{tileRow}

topLeftCorner = [xmin, ymax]
tileAddress = [tileCol, tileRow] = gagrid.tileAddress(zoom, topLeftCorner)
print(tileAddress)
>>> [6, 7]

# Get the parent tiles
parentZoom = 1
gagrid.getParentTiles(zoom, tileCol, tileRow, parentZoom)
>>> [[1, 0, 0]]

# It also works if the point is within the tile
pointInTile = [topLeftCorner[0] + 200.0, topLeftCorner[1] - 200.0]
print(gagrid.tileAddress(zoom, pointInTile))
>>> [7, 6]

# Resolution in meters
print(gagrid.getResolution(zoom))
>>> 50.0

# Scale dpi dependent (defaults to 96)
print(gagrid.getScale(zoom, dpi=96.0))
>>> 188976.0

# Tile size in meters
print(gagrid.tileSize(zoom))
>>> 12800.0

# Number of tiles at zoom
print(gagrid.numberOfTilesAtZoom(zoom))
>>> 950
# Extent dependent
print(gagridExtent.numberOfTilesAtZoom(zoom))
>>> 253

# Get the closest zoom for a given resolution
print(gagrid.getClosestZoom(245))
>>> 16

# Get the ceiling zoom for a given resolution
print(gagrid.getCeilingZoom(245))
>>> 17

# Generate tilesSpec
minZoom = 16
maxZoom = zoom
tilesSpecGenerator = gagrid.iterGrid(minZoom, maxZoom)
for i, t in enumerate(tilesSpecGenerator):
    (tileBounds, zoom, tileCol, tileRow) = t
    print(t)
    if i == 1:
        break
>>> ([420000.0, 286000.0, 484000.0, 350000.0], 16, 0, 0)
>>> ([484000.0, 286000.0, 548000.0, 350000.0], 16, 1, 0)
# Extent dependent
tilesSpecGeneratorExtent = gagridExtent.iterGrid(minZoom, maxZoom)
for i, t in enumerate(tilesSpecGeneratorExtent):
    (tileBounds, zoom, tileCol, tileRow) = t
    print(t)
    if i = 1:
        break
>>> ([484000.0, 222000.0, 548000.0, 286000.0], 16, 1, 1)
>>> ([548000.0, 222000.0, 612000.0, 286000.0], 16, 2, 1)

This module also provides a simple grid API for grid cells addressing.

from gatilegrid import Grid

extent = [485349.96, 75250.055, 833849.959, 295950.054]
resolutionX = 100.0
resolutionY = -100.0
grid = Grid(extent, resolutionX, resolutionY)

# We use singed resolution to define the origin.
# Here the origin is at the top-left corner.
print(grid.origin)
>>> [485349.96, 295950.054]

# The Grid class defines a series of useful properties
print(grid.cellArea)
>>> 10000.0
print(grid.nbCellsX)
>>> 3485
print(grid.nbCellsY)
>>> 2207
print(grid.isTopLeft)
>>> True
print(grid.isBottomRight)
>>> False

[col, row] = grid.cellAddressFromPointCoordinate([500000, 100000])
print(col)
>>> 146
print(row)
>>> 1959

# Get the extent of the cell using its address
cellExtent = grid.cellExtent(col, row)
print(cellExtent)
>>> [499949.96, 99950.054, 500049.96, 100050.054]

# Get an address range using an extent
[minCol, minRow, maxCol, maxRow] = grid.getExtentAddress([500000, 100000, 550000, 150000])
print(minCol)
>>> 146
print(minRow)
>>> 1459
print(maxCol)
>>> 646
print(maxRow)
>>> 1959

Tests

source .venv/bin/activate
python setup.py test

Publish a new version of the module

Edit $HOME/.pypirc and add (username and password in keepass):

[distutils]
index-servers =
  pypi
  pypitest

[pypi]
repository=https://upload.pypi.org/legacy/
username=iwi***
password=

[pypitest]
repository=https://test.pypi.org/legacy/
username=iwi***
password=

Bump version in setup.py.

Build, check and upload the new module to the test repository:

pip install --upgrade twine wheel setuptools
python setup.py sdist bdist_wheel
twine upload --repository testpypi dist/*

Test local install from test repository.

pip install -i https://test.pypi.org/simple/ gatilegrid

If everything is ok, push the new version to the default repository.

twine upload --repository pypi dist/*

Test the newly created module.

Create a RELEASE in github.

CONTRIBUTORS:

• Loic Gasser
• Marc Monnerat
• Nadine Piveteau
• Marcel Clausen
• Gilbert Jeinziner