How to report bug with Sample tool generating serious, but hard to detect, artefacts in the resulting data sets in latest version of ArcGIS For Desktop 10.4

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10-21-2016 02:18 PM
ColinMacLeod
New Contributor

When doing a training session today for a group of marine biologists, it became clear that the Sample tool (SPATIAL ANALYST TOOLS> EXTRACTION> SAMPLE) in the latest version of ArcGIS For Desktop (10.4 - downloaded and installed by the participants this week) has a bug in it which means that when you use one raster data layer to extract values from other raster data layers, it populates some data rows with the value -9999. Other values appear to be interpolated with values that are clearly artefacts of the extraction process as they generate impossible values (e.g. negative values for raster cell values of Slope).

This was only a problem with people who were using ArcGIS 10.4 and not those using ArcGIS 10.3 or 10.2. (or indeed 9.3), and occurred on every machine running this version of ArcGIS. It also occurred every time the Sample tool was used with and with multiple different data sets.

While there is a work around by turning the raster data layer into a point data layer and then using the Extract Multi Values To Points tool (SPATIAL ANALYST TOOLS> EXTRACTION> EXTRACT MULTI VALUE TO POINTS), this issue means that the standard protocols used to analyse marine biological data when producing species distribution models (SDMs) no longer function as they should. Worse than this, this problem doesn't return an error message, but rather generates artefacts within the resulting data set without any warning meaning it is all too easy for people to assume that the data set created by the tool is reliable when it isn't, and since SDMs are commonly used to make important management and conservation decisions, this has serious real-world implications.

 

My question is this: Is there anywhere that such bugs can be reported so they can be fixed ASAP? At the moment, there is a lot of pressure to shift across to open source alternatives to ArcGIS (such as QGIS), and suddenly encountering situations where previously good tools in ArcGIS no longer function as they should and instead produce data sets with serious, but hard to detect, artefacts, means that most of those in the training session were left feeling they would be better off using QGIS rather than ArcGIS because the appropriate tools in QGIS worked as they should without generating such artefacts (and without having to use awkward, non-standard, work-arounds). It doesn't help that there appears to be no standard protocol for reporting such bugs, and so  no way of providing re-assurance as to when it it might be sorted.

Any feedback on what do to about such situations would be gratefully appreciated as I was left at a loss as to what to tell the people I was meant to be training.

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DanPatterson_Retired
MVP Emeritus

I will flag timothy_hales-esristaff‌ to see if this is on the "issues addressed" in the 10.5 documentation which isn't available online yet.  Or perhaps, someone on the geoprocessing team might know if it is a known issue.

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6 Replies
DanPatterson_Retired
MVP Emeritus

Well bug reporting is pretty standard, you go to support and file an incident.   But I am pretty sure anyone can file a report, but you will need to provide a detailed summary of what happened and the test data.

Esri Support Home 

Based on your case..

1st ... Sample—Help | ArcGIS for Desktop 

It appears that you need to report

  • First is the raster environment settings.
    • Can it be assumed that everything was in the same coordinate system, cell size and that each raster had their cells aligned? (ie was a snap raster used)
  • The output destination (this would account for the -9999)
    • Locations that sample NoData cells in the input raster, or rasters, will be given a <null> value in an output geodatabase table. For output to INFO or .dbf, since the concept of null is not supported, a value of -9999 will be given.  
  • The sampling method since that will determine output results
    • When the input rasters are two-dimensional, the field type of the sampled values in the output table is always floating point. This is to ensure that the appropriate degree of precision is retained if the bilinear or cubic options for the resampling technique were to be selected.
  • the whole issue of the inputs and their environment settings
    • When the location input is raster, for best results, the cell size and registration of the input rasters and the location raster should be the same.
  • multipoints are not supported

The alternate method also has a number of requirements as well

2nd .. Extract Multi Values to Points—Help | ArcGIS for Desktop 

There are a whole list of things that come to mind based upon the contents therein.

  • First is the raster environment settings.
    • Can it be assumed that everything was in the same coordinate system, cell size and that each raster had their cells aligned? (ie was a snap raster used)
  • What interpolation method was used?
    • The interpolation option determines how the values will be obtained from the raster. The default option is to use the value at the center of the cell being sampled. The interpolation option will use bilinear interpolation to interpolate a value for the cell center.
  • were you using a geodatabase featureclass as input for sampling?
    • Locations that sample NoData cells in the input raster, or rasters, will be given a <null> value when the input point features are in a geodatabase. When the input is a shapefile, since the concept of null is not supported, a value of -9999 will be given.
  • The sampling points weren't multipoints?
    • Multipoint datasets are not supported as input.

And finally, there is a reference to checking other environment section options for aspects that may affect the outputs.

So can you go over your workflow and produce some outputs considering the required inputs and how they did or didn't conform to the above requirements.

ColinMacLeod
New Contributor

Hi Dan,

Thanks for the quick reply. All the requirements you mentioned were checked and double-checked (since, as you suggest, these are usually the source of problems with this tool), but the problem was not caused by any of these. In addition, it's not caused by missing values as all the rasters being used had values for all cells, and the same data sets work with the same tool in ArcGIS 10.3.

In terms of reporting this bug with ArcGIS 10.4, part of the problem is that: A. I'm not based on the USA (which means that everything has to go through the regional distributor), and B. Since I was training other people on their own computers from their organisation, it seems I cannot easily report it as I don't have ArcGIS support myself. This is not a problem for me as all I want to do is to be able to report the problem I came across with this tool (as well as providing sample data sets etc) so that ESRI can hopefully do something about it for other users (rather than looking for support as such). It seems odd that there isn't a simple online big reporting system for ArcGIS, like there is for QGIS and other software.

Thanks again for taking the time to reply.

All the best,

Colin

PS The work around I noted works with the same data sets, it's just that it would mean potentially having to notify and re-train rather a lot of people around the world for what has become a standard analytical process for marine biologists.

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DanPatterson_Retired
MVP Emeritus

I will flag timothy_hales-esristaff‌ to see if this is on the "issues addressed" in the 10.5 documentation which isn't available online yet.  Or perhaps, someone on the geoprocessing team might know if it is a known issue.

ColinMacLeod
New Contributor

Hi Dan,

That would be perfect. Thank for flagging it up. I'm happy to provide any required info on data sets, the exact process that generated the bug etc if that will help.

All the best,

Colin

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TimothyHales
Esri Notable Contributor

cdmacleod‌ Anyone can contact Esri Technical Support to log a bug even if they do not have support. I will reach out to our support team so that we can get this bug logged. Thanks!

KirstenPinkston
Esri Contributor

Hi cdmacleod‌, I'm with the Support team here at Esri. Thank you for providing us with this feedback! I would like to get you a ticket logged so that we can document your repro case and get a bug logged. Please personal message me an email address that you prefer to be reached at, and I'll have someone contact you as soon as possible. Thanks again!