Question

How to display the closest ascii pixel to a poly line

T
Hi guys,

 

 

I am having trouble with spatially querying between an Ascii file and a polyline (shapefile).

 

What i want to do is find the cloest pixel point in the ascii file and insert it into a new attribute column within the shapefile polyline

 

The ascii files has theses attributes "Row & Column" eg 1182, 1657 - "Ground Location" eg co-ordinates - "Band 0 (REAL64)" eg 19.2234.

 

 

ao what i want is the closest band attribute to be inserted into the shape file as a new attribute.

 

I have tried to use the neighborfinder but it doesn't seem to want to match anything.

 

 

Does anyone no how to do this?

 

 

Cheers

 

 

Trent

4 replies

takashi
Rank
Userlevel 2
Badge +17
Hi Trent,

 

 

The RasterCellCoercer can be used to transform every cell into point than has the band value as an attribute. You can then find the closest point from the line with the NeighborFinder.

 

 

Takashi
T
Hi Takashi,

 

 

thank you for that bit of info, it worked to a point. I can get all the relevant info  to come through from the neighborfinder eg distance, closest x & y etc but for some reason the raster attributes don't want to flow through is there any reason for this.

 

I have included a link through to the sample fmw file and sample data if that helps?

 

https://www.dropbox.com/sh/xyel5fsj0kouz9f/AAB6GJM2F1tFaq9uQNzaYk61a?dl=0

 

 

 

Any help as always much appreciated.

 

 

Cheers

 

 

Trent
takashi
Rank
Userlevel 2
Badge +17
The "_band{}.value" is a list attribute that contains band values as its elements. You will have to get your required element value when writing it into a destination file. The raster read from an ascii grid file has just one band, so the required value will be stored in the first element of the list. i.e. "_band{0}.value".

 

 

Right-click on the list name and expose the element. Then, you can map the exposed element "_band{0}.value" to an attribute of the writer feature type.

 

 

 

Alternatively you can change a list element to non-list attribute by a transformer such as ListIndexer, AttributeRenamer etc.
T
that's awesome Takashi, it work's a treat :) thanks alot for your help

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