Hi, I have an .asc file that contains a maximum flood extent. All i want to do is convert the maximum output of the asc to a shapefile and a tab file. anybody go any ideas? had a read of alot of poasts, but cant find anything similar. Cheers.
Question
How to convert the maximum output of an .asc to a shapefile and a tab file
This post is closed to further activity.
It may be an old question, an answered question, an implemented idea, or a notification-only post.
Please check post dates before relying on any information in a question or answer.
For follow-up or related questions, please post a new question or idea.
If there is a genuine update to be made, please contact us and request that the post is reopened.
It may be an old question, an answered question, an implemented idea, or a notification-only post.
Please check post dates before relying on any information in a question or answer.
For follow-up or related questions, please post a new question or idea.
If there is a genuine update to be made, please contact us and request that the post is reopened.
By .asc I'm assuming you mean an ESRI ASCII grid file. There are several ways to convert a raster to vector for output to shape, including these two transformers:
- RasterCellCoercer: converts each raster cell into either a polygon or a pixel with the raster cell value as an attribute
- RasterToPolygonCoercer: Outputs polygons of contiguous raster cell values
Let us know if that doesn't cover what you need.
By .asc I'm assuming you mean an ESRI ASCII grid file. There are several ways to convert a raster to vector for output to shape, including these two transformers:
- RasterCellCoercer: converts each raster cell into either a polygon or a pixel with the raster cell value as an attribute
- RasterToPolygonCoercer: Outputs polygons of contiguous raster cell values
Let us know if that doesn't cover what you need.
Hi @david_r, Thanks for the responce. Yea it is an ESRI file. I used the RasterToPolygonCoercer , however it has created ( currently ) 85,000 lines and polygons. I think I need to re-class the ASCII before I convert it to a Shapefile?
To clarify, I have a maximum depth grid ASCII output from Tuflow. All I want to do is have a shapefile showing what the max outlines are.
How can I edit the ASCII to get rid of the Z values, then translate to a shapefile?
Cheers,
Mike.
I'm not quite sure I understand precisely what you need, but if you need to reclassify the raster you can look at this answer from @takashi: https://knowledge.safe.com/questions/35421/classify-raster-data-by-breakpoints.html
If you need depth contours, you can use the RasterCellCoercer to convert the grid to points and send them to the ContourGenerator.
If nothing of the above fits, please consider posting an example of what you need, e.g. a screenshot or an illustration.