gatilegrid 0.1.4

Popular tile grids and grids API for web mapping applications

gatilegrid
===========

[](https://travis-ci.org/geoadmin/lib-gatilegrid)

## Geoadmin custom tile grid for web mapping applications

gatilegrid is compatible with python 2.7 and 3.5

## Installation

```bash
$ 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`).


```python
from gatilegrid import getTileGrid

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
print gagrid.tileAddressTemplate
>>> [496800.0, 247600.0, 509600.0, 260400.0]
>>> {zoom}/{tileCol}/{tileRow}

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

# 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

# Generate tilesSpec
counter = 0
minZoom = 16
maxZoom = zoom
tilesSpecGenerator = gagrid.iterGrid(minZoom, maxZoom)
for t in tilesSpecGenerator:
(tileBounds, zoom, tileCol, tileRow) = t
print t
counter += 1
if counter == 2:
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
counter = 0
tilesSpecGeneratorExtent = gagridExtent.iterGrid(minZoom, maxZoom)
for t in tilesSpecGeneratorExtent:
(tileBounds, zoom, tileCol, tileRow) = t
print t
counter += 1
if counter == 2:
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.

```python
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
print row
>>> 146
>>> 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 env/bin/activate
python setup.py test

```

### Upload module

Make sure your libs are up to date.

```
pip install wheel twine setuptools --upgrade
python setup.py sdist upload -r pypitest
python setup.py sdist upload -r pypi
python setup.py bdist_wheel upload -r pypitest
python setup.py bdist_wheel upload -r pypi
```

#### CONTRIBUTORS:

- [Loïc Gasser](https://github.com/loicgasser)