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Questions tagged [m-values]

The tag has no usage guidance.

1
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1answer
29 views

Cannot solely remove M value of Shapefiles

I have a couple of Shapefiles which are of geometry type ZM (like PolygonZM, MultiLineStringZM, etc.), however my database (a PostGIS database) is of geometry type Z (like PolygonZ, MultiPointZ, etc.)....
1
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0answers
73 views

Calibrate routes not lining up with calibration points [closed]

I am currently building a model that calibrates Z and M values from Cross Sections for a stream. Z being the 100yr flood and M being the station number. What's happening is the vertex on the stream ...
1
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1answer
181 views

Assigning attributes values to PointZM and convert to LineZM Geometries in QGIS? [closed]

I have elevation and measured values in attribute table of points layer. Is there a way to convert this layer into PointZM (with elevation and measured) and assign elevation and measured values to ...
4
votes
1answer
184 views

Recover M-values from PostGIS `ST_Intersection`?

I am querying the intersection of a path (LinestringZM) through a region (MultiPolygon) but the ST_Intersection returns only the Lat/Long/Alt coordinates and I need to recover time, stored in the M ...
2
votes
1answer
66 views

Determining distance on line of point, given measure?

I need to determine into a standalone python script the distance of a point on a polyline with M-values and its' coordinates, at a specific measure. For example, I have to calculate the X,Y of a ...
10
votes
2answers
1k views

QGIS Extract Nodes with M-Values for Linear Referencing

I have a MultiLineStringZM layer in a sqlite database, and I'm trying to visualize the measures or m-values at the vertexes. I've tried looking up information on how to do this in QGIS, and about all ...
1
vote
1answer
265 views

Where can I find some Sample Data for Linear Referencing?

I'm teaching GIS at a Local college, and one of the classes is on Linear Referencing, specifically of Roads. For the Practical classes, I need some Sample Data for Linear Referencing. Ideally, this ...
3
votes
2answers
1k views

Drop M values from MULTIPOLYGON with PostGIS?

The title is self-explanatory. I wonder if there is a simple function like ST_Force2D for the M values?