Question

Snipper point in exit

  • 10 April 2018
  • 8 replies
  • 13 views
G
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Hello everybody.

I've a question with the transformer Snipper.

Before transformer I've lines with start and end measure.

My transformer parameters are :

After transformer I've cut lines with the start and end measure of before and points alones.

I don't understand why I've points in exit have you got any idea ?

Thank you for your help.

8 replies

david_r
Rank
Userlevel 4

Can you give us a concrete example of a line, including m-values, and some values for "_measure" and "_end_measure"?

Or even better, post a sample workspace with a small test dataset that demonstrates the issue.

G
Badge +3

Might you have fed it the lines which are defined by their start and end measures already?

Then it might snip them at the begin and end, yielding points if it is not exactly the same as the true location of the vertices of the lines, you might end up with point or point like features.

That's why you can use begin and start instead.

Or your maybe start and end measures are equal.

Geuss sample data is idd a good idea.

G
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Thanks for the test data and workspace, that's very helpful. There are at least two different problems with the values given to the Snipper, as seen in the shapefile:

  • Sometimes the start/end measures are out of range compared to line. This is shown in the FME log, e.g. "@Snip (or FMELine::snip) was given Measures of 0.0390917661 and 0.0390917661, which are out of range for a line with min/max measures of 0 and 0.006715436606972919. Snapping params to closest valid value." If both the start and end measure is outside the scope of the line (as is the case here), you'll end up with a zero-length line = a point.

     

  • There are lots of features where the start and end measure is identical, meaning that you'll end up with a zero-length line = a point.

You may want to take a closer look at the algorithm that calculates the start and end measures for the Snipper.

Thank you for your help, this is an extract for testing : forums-tests.zip

G
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Thank you for your help, this is an extract for testing : forums-tests.zip

In fact I think because I've the same start and end coordinate, but why I've lines and points and not lines or nothing ?

 

 

david_r
Rank
Userlevel 4

Thanks for the test data and workspace, that's very helpful. There are at least two different problems with the values given to the Snipper, as seen in the shapefile:

  • Sometimes the start/end measures are out of range compared to line. This is shown in the FME log, e.g. "@Snip (or FMELine::snip) was given Measures of 0.0390917661 and 0.0390917661, which are out of range for a line with min/max measures of 0 and 0.006715436606972919. Snapping params to closest valid value." If both the start and end measure is outside the scope of the line (as is the case here), you'll end up with a zero-length line = a point.

     

  • There are lots of features where the start and end measure is identical, meaning that you'll end up with a zero-length line = a point.

You may want to take a closer look at the algorithm that calculates the start and end measures for the Snipper.

G
Badge

Thanks for the test data and workspace, that's very helpful. There are at least two different problems with the values given to the Snipper, as seen in the shapefile:

  • Sometimes the start/end measures are out of range compared to line. This is shown in the FME log, e.g. "@Snip (or FMELine::snip) was given Measures of 0.0390917661 and 0.0390917661, which are out of range for a line with min/max measures of 0 and 0.006715436606972919. Snapping params to closest valid value." If both the start and end measure is outside the scope of the line (as is the case here), you'll end up with a zero-length line = a point.

     

  • There are lots of features where the start and end measure is identical, meaning that you'll end up with a zero-length line = a point.

You may want to take a closer look at the algorithm that calculates the start and end measures for the Snipper.

Maybe this is when I build the shapefile because in my treatment I don't have this message

 

 

G
Badge

Thanks for the test data and workspace, that's very helpful. There are at least two different problems with the values given to the Snipper, as seen in the shapefile:

  • Sometimes the start/end measures are out of range compared to line. This is shown in the FME log, e.g. "@Snip (or FMELine::snip) was given Measures of 0.0390917661 and 0.0390917661, which are out of range for a line with min/max measures of 0 and 0.006715436606972919. Snapping params to closest valid value." If both the start and end measure is outside the scope of the line (as is the case here), you'll end up with a zero-length line = a point.

     

  • There are lots of features where the start and end measure is identical, meaning that you'll end up with a zero-length line = a point.

You may want to take a closer look at the algorithm that calculates the start and end measures for the Snipper.

In fact yes I've this problem, and I don't know why because I extract a measure from line to point with PointOnLineOverlayer and after I use Featuremerger and Snipper like the treatment dynamic-line-segmentation-2.fmwt describe here

 

 

G
Badge
In fact yes I've this problem, and I don't know why because I extract a measure from line to point with PointOnLineOverlayer and after I use Featuremerger and Snipper like the treatment dynamic-line-segmentation-2.fmwt describe here

 

 

I found the problem I've duplicate geometry !

 

 

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