Category: Tutorials

Mapping Google Location Data

A cool python script has been created that allows you to easily convert your google location (Takeout) data into a shapefile.

You can get your data from: Google Takeout
And you only need the “Location History – JSON format”

The conversion python script can be downloaded from: GitHub

The python script requires GDAL and its python bindings, but can be easily run if you installed QGIS using the OSGeo4W installer. From the advanced installer, under the Lib section.

instruct

Then using the OSGeo4W Shell.
shell

Run the command:

python "C:\FullPath_to_Python_Script\read_location_data.py" "C:\FullPath_to_Input_File\LocationHistory.json" "C:\output_path" output_file_name ESRI_Shapefile

Example:

python "C:\FilePath\Takeout\Location History\read_location_data.py" "C:\FilePath\Takeout\Location History\LocationHistory.json" "C:\FilePath\Takeout\Location History" output ESRI_Shapefile

Then just style it in QGIS as desired.
GoogleTakeOut

GIS to CAD using ogr2ogr – Part 3 – Point Annotation to Text in CAD

GIS to CAD using ogr2ogr – Part 1 – Shp to DXF with Contour Data
GIS to CAD using ogr2ogr – Part 2 – GML to DXF with OS MasterMap

MasterMap Topo Sample Data:

https://www.ordnancesurvey.co.uk/business-and-government/licensing/sample-data/discover-data.html

OS MasterMap has an annotation layer, which is simple to symbolise in a GIS program. But becomes more difficult in CAD software.

With ogr2org, when writing a DXF file, if you have an input point geometry, which has an OGR_STYLE attribute, it will be written as a text geometry when opened in CAD.

So for our MasterMap data we have one layer we want to convert to text:
CartographicText

ogrinfo os-mastermap-topography-layer-sample-data.gml CartographicText
OGRFeature(CartographicText):855
fid (String) = osgb1000000729425681
featureCode (Integer) = 10026
version (Integer) = 1
versionDate (String) = 2001-11-11
theme (StringList) = (1:Buildings)
changeDate (StringList) = (1:1999-09-08)
reasonForChange (StringList) = (1:Modified)
descriptiveGroup (StringList) = (1:Buildings Or Structure)
physicalLevel (Integer) = 50
anchorPosition (Integer) = 0
font (Integer) = 2
height (Real) = 1.5
orientation (Integer) = 2890
textString (String) = 5
descriptiveTerm (String) = (null)
make (String) = Manmade
POINT (290875.38 92635.81)

So for this we are primarily interested in “textString” and potentially “orientation”.

Lets see the layer as points first as a baseline:

ogr2ogr -f DXF CartographicText.dxf os-mastermap-topography-layer-sample-data.gml CartographicText

Screenshot[10]

Zoomed in:

Screenshot[11]

But lets try that as text. We will keep this simple and only take into account orientation and to a small extent height. Lets look at orientation:

Orientation – The orientation of text or symbol features for cartographic placement. This is measured in tenths of a degree anticlockwise from due east (0–3599).

So conversion to degree will be simple. Orientation/10

We can also take into consideration height as a multiplier.

And “textString” stores the text itself.

The command:

ogr2ogr.exe -f DXF CartographicText2.dxf os-mastermap-topography-layer-sample-data.gml CartographicText -sql "SELECT 'LABEL(f:""Arial"",s:""'||(height*800)||'"",t:""'||textString||'"",a:""'||(orientation/10)||'"",p:5)' AS OGR_STYLE, * FROM CartographicText" -dialect SQLITE

Full extent:

Screenshot[12]

Zoomed in:

Screenshot[13]

Explained:

Since this is run in windows, through the regular console, the escape character for quotes is two quotes “”‘. So a combination on ‘ ” and “”‘ we can accommodate all the required quotes.

f:””Arial””,s:””‘||(height*800)||'””,t:””‘||textString||'””,a:””‘||(orientation/10)||'””,p:5

f:””Arial””
Font: Arial

s:””‘||(height*800)||'””
Size: Multiplier of the height field, I am not sure what the units are, comments appreciated.

t:””‘||textString||'””
Text: textString column

a:””‘||(orientation/10)||'””
Align: In degrees

p:5
Position: the OS position and the ogr2ogr style position are slightly different, so better placement could be achieved with some pre-processing

GIS to CAD using ogr2ogr – Part 1 – Shp to DXF with Contour Data
GIS to CAD using ogr2ogr – Part 2 – GML to DXF with OS MasterMap