Hi, I am using arcgis 10.5.1 64 bit. I have a set of 10 point features that I am trying to connect using PathDistance. Each point has an id, say 0...9. Effectively I want to generate the path from 0 to 1, 1 to 2, and so on. I am using both my own tables to define vertical and horizontal factors. I have created these paths manually using the exact same factors. So I know those work. The two main files I am using are: 1) a sample DEM (5m resolution, tif) called test_dem.tif 2) a point shapefile test_loc.shp which contains 11 points with several columns but the main one used here is 'Id' column. These files and others used for the script can be found below. The files used for the vertical and horizontal factors are the following, hsine.txtvertical3.txt0 1 10 1.02 20 1.06 30 1.13 40 1.23 50 1.36 60 1.5 70 1.66 80 1.83 90 2 100 2.17 110 2.34 120 2.5 130 2.64 140 2.77 150 2.87 160 2.94 170 2.98 180 3 -90 20000 -80 5000 -70 1500 -60 300 -50 100 -40 40 -30 12 -20 3 -10 1 0 3 10 7 20 14 30 24 40 40 50 75 60 180 70 750 80 1500 90 5000 I have the following code: import arcpy import arcpy . sa as sa import arcpy . management as mng from math import pi # Checking out SA extension class SAerror ( Exception ) : pass try : if arcpy . CheckExtension ( 'Spatial' ) == 'Available' : arcpy . CheckOutExtension ( 'Spatial' ) else : raise SAerror except SAerror : print ( 'Spatial Analyst license is unavailable!' ) except arcpy . ExecuteError : print ( arcpy . GetMessages ( 2 ) ) # ArcGIS directories arcpy . env . scratchWorkspace = r 'C:\GIS\projects\network\potential\SCRATCH' arcpy . env . workspace = r 'C:\GIS\projects\network\potential' # input rasters rDEM = arcpy . Raster ( r 'C:\GIS\projects\network\potential\tst_dem.tif' ) shpFeat = r 'C:\GIS\projects\network\potential\testloc.shp' # PARAMETERS deg2rad = pi / 180.0 rad2deg = 180.0 / pi wFactor = 0.2 I = 4.0 wPthPot = 0.75 Gmax = 5.0 # path distance parameters rCost = "" # use unit rSurface = rDEM rVertical = rDEM hCostfn = r 'C:\GIS\projects\network\potential\hsine.txt' HF = sa . HfTable ( hCostfn ) vCostfn = r 'C:\GIS\projects\network\potential\vertical3.txt' VF = sa . VfTable ( vCostfn ) maxDist = "" nbrfn = r 'C:\GIS\projects\network\potential\expd.txt' #Set geoprocessing environmental preferences arcpy . env . extent = rDEM . extent arcpy . env . cellSize = rDEM . meanCellHeight arcpy . env . overwriteOutput = True # INITIAL CONDITIONS rTPot = rDEM / rDEM . maximum rDirRel = rTPot rG0 = sa . CreateConstantRaster ( 0.0 , 'FLOAT' , arcpy . env . cellSize , arcpy . env . extent ) rGmax = sa . CreateConstantRaster ( Gmax , 'FLOAT' , arcpy . env . cellSize , arcpy . env . extent ) rGt_1 = sa . CreateConstantRaster ( 0.0 , 'FLOAT' , arcpy . env . cellSize , arcpy . env . extent ) # sample sequence pthseq = list ( range ( 11 ) ) # create a feature layer mng . MakeFeatureLayer ( shpFeat , 'lyr' ) # MAIN for o , d in zip ( pthseq [ : - 1 ] , pthseq [ 1 : ] ) : # lambda direction rDir = sa . Aspect ( rDirRel ) # CALCULATE PATH mng . SelectLayerByAttribute ( 'lyr' , "NEW_SELECTION" , ' "Id" = ' + str ( o ) ) # origin # accumulated cost surface rAcs = sa . PathDistance ( 'lyr' , "" , rSurface , rDir , HF , rVertical , VF , "" , 'rBL.tif' ) mng . SelectLayerByAttribute ( 'lyr' , "NEW_SELECTION" , ' "Id" = ' + str ( d ) ) # destination # path rPath = sa . CostPath ( 'lyr' , rAcs , 'rBL.tif' , "EACH_CELL" ) rPath = sa . Con ( sa . IsNull ( rPath ) , 0 , 1 ) pathFn = 'path' + str ( o ) + '_' + str ( d ) + '.tif' rPath . save ( pathFn ) rW = ( rG0 - rGt_1 ) * wFactor rMark = rPath * ( 1.0 - ( rGt_1 / rGmax ) ) * I rGt = rGt_1 + rW + rMark rGt . save ( 'rGt.tif' ) # DECAY rPthPot = sa . FocalStatistics ( rGt , sa . NbrWeight ( nbrfn ) , 'SUM' ) rPthPot = rPthPot . maximum - rPthPot rPthPot = rPthPot / rPthPot . maximum # Update directional relation rDirRel = rPthPot * wPthPot + rTPot * ( 1.0 - wPthPot ) # Update rGt_1 *** missing earlier *** rGt_1 = rGt Overall, I get very weird behavior. Some times, it will fail when trying to generate the backlink. In other occasions, it will calculate the first path and then fail. It will calculate three paths and fail. Only once it has ran through the entire sequence. After crashing I make sure to delete all possible files (usually the backlink file is created but it is corrupted). I have tried many things: 1. Creating a fresh feature layer and erasing it at the end of each iteration. 2. Generating with each iteration different feature layers, one for the origin and another for the destination, and deleting them after each iteration. 3. I have tried saving to the disk the layer feature as well as all the other rasters (I set arcpy to overwrite). 4. I have tried saving to the disk the backlink 5. I have used relative and absolute filenames. 6. I am using only .tif files 7. I have use try...except to catch information about the error with no success I have spent much time reading through the different forums, etc. I know there were problems with this method in previous iterations of the software. The lack of any feedback relating to possible errors is a real problem! Often it will be python that crashes all together. It is very finicky, there are certain Horizontal Factor settings (even those found in the help pages) that will not generate a complete cost accumulation raster. This is not my case though. My question is whether there is something that I am missing, something that needs to be reset or deleted? or perhaps someone can suggest how to find more information after the procedure fails??? thank you, Marc pathdistance.zip

I guess in that case it would be best to contact support and see if they know why the error occurs. Edit: in case you have a tool that executes correctly in Pro and when you run script it does not, you should try to isolate the problem. When you execute a tool you can copy the Python snippet from the Results window. In case you execute that snippet does that work (generating a new result)?

Hi xander_bakker and Dan_Patterson, Still have not resolved this... When I run the script (as is) using arcgis pro 2.01, it stops the first time it encounters PathDistance with an error. If, however, I run it through the desktop application (with the exact same parameters) it works fine. Can any of you suggest ways in which I could explore this behavior? By that I mean... what are the possible differences when running it as a script or through the application? Perhaps there lies the problems.... thanks, Marc

Thanks Neil,... I did find out at the end (only two options). Still running into a non-descrip error with no clue as to why things do not work. Marc

nav[aria-label="Primary Navigation"] { padding: 0; & ul { list-style: none; width: 100%; display: flex; flex-direction: row; justify-content: start; align-items: start; gap: 30px; padding: 0; & li { margin: 0; } & ul li { list-style: none; } } }

Path Distance erratic and crashes in a loop

MLLO

Hi,

I am using arcgis 10.5.1 64 bit.

I have a set of 10 point features that I am trying to connect using PathDistance. Each point has an id, say 0...9. Effectively I want to generate the path from 0 to 1, 1 to 2, and so on.

I am using both my own tables to define vertical and horizontal factors. I have created these paths manually using the exact same factors. So I know those work.

The two main files I am using are: 1) a sample DEM (5m resolution, tif) called test_dem.tif 2) a point shapefile test_loc.shp which contains 11 points with several columns but the main one used here is 'Id' column. These files and others used for the script can be found below.

The files used for the vertical and horizontal factors are the following,

hsine.txt	*vertical3.txt*
0 1 10 1.02 20 1.06 30 1.13 40 1.23 50 1.36 60 1.5 70 1.66 80 1.83 90 2 100 2.17 110 2.34 120 2.5 130 2.64 140 2.77 150 2.87 160 2.94 170 2.98 180 3	-90 20000 -80 5000 -70 1500 -60 300 -50 100 -40 40 -30 12 -20 3 -10 1 0 3 10 7 20 14 30 24 40 40 50 75 60 180 70 750 80 1500 90 5000

I have the following code:

<SPAN class="keyword token">import</SPAN> arcpy
<SPAN class="keyword token">import</SPAN> arcpy<SPAN class="punctuation token">.</SPAN>sa <SPAN class="keyword token">as</SPAN> sa
<SPAN class="keyword token">import</SPAN> arcpy<SPAN class="punctuation token">.</SPAN>management <SPAN class="keyword token">as</SPAN> mng
<SPAN class="keyword token">from</SPAN> math <SPAN class="keyword token">import</SPAN> pi

<SPAN class="comment token"># Checking out SA extension</SPAN>
<SPAN class="keyword token">class</SPAN> <SPAN class="token class-name">SAerror</SPAN><SPAN class="punctuation token">(</SPAN>Exception<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">pass</SPAN>
<SPAN class="keyword token">try</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">if</SPAN> arcpy<SPAN class="punctuation token">.</SPAN>CheckExtension<SPAN class="punctuation token">(</SPAN><SPAN class="string token">'Spatial'</SPAN><SPAN class="punctuation token">)</SPAN> <SPAN class="operator token">==</SPAN> <SPAN class="string token">'Available'</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; arcpy<SPAN class="punctuation token">.</SPAN>CheckOutExtension<SPAN class="punctuation token">(</SPAN><SPAN class="string token">'Spatial'</SPAN><SPAN class="punctuation token">)</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">else</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">raise</SPAN> SAerror
<SPAN class="keyword token">except</SPAN> SAerror<SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">print</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="string token">'Spatial Analyst license is unavailable!'</SPAN><SPAN class="punctuation token">)</SPAN>
<SPAN class="keyword token">except</SPAN> arcpy<SPAN class="punctuation token">.</SPAN>ExecuteError<SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp; <SPAN class="keyword token">print</SPAN><SPAN class="punctuation token">(</SPAN>arcpy<SPAN class="punctuation token">.</SPAN>GetMessages<SPAN class="punctuation token">(</SPAN><SPAN class="number token">2</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">)</SPAN>

<SPAN class="comment token"># ArcGIS directories</SPAN>
arcpy<SPAN class="punctuation token">.</SPAN>env<SPAN class="punctuation token">.</SPAN>scratchWorkspace <SPAN class="operator token">=</SPAN> r<SPAN class="string token">'C:\GIS\projects\network\potential\SCRATCH'</SPAN>
arcpy<SPAN class="punctuation token">.</SPAN>env<SPAN class="punctuation token">.</SPAN>workspace <SPAN class="operator token">=</SPAN> r<SPAN class="string token">'C:\GIS\projects\network\potential'</SPAN>

<SPAN class="comment token"># input rasters</SPAN>
rDEM <SPAN class="operator token">=</SPAN> arcpy<SPAN class="punctuation token">.</SPAN>Raster<SPAN class="punctuation token">(</SPAN>r<SPAN class="string token">'C:\GIS\projects\network\potential\tst_dem.tif'</SPAN><SPAN class="punctuation token">)</SPAN>
shpFeat <SPAN class="operator token">=</SPAN> r<SPAN class="string token">'C:\GIS\projects\network\potential\testloc.shp'</SPAN>

<SPAN class="comment token"># PARAMETERS</SPAN>
deg2rad <SPAN class="operator token">=</SPAN> pi<SPAN class="operator token">/</SPAN><SPAN class="number token">180.0</SPAN>
rad2deg <SPAN class="operator token">=</SPAN> <SPAN class="number token">180.0</SPAN><SPAN class="operator token">/</SPAN>pi
wFactor <SPAN class="operator token">=</SPAN> <SPAN class="number token">0.2</SPAN>
I <SPAN class="operator token">=</SPAN> <SPAN class="number token">4.0</SPAN>
wPthPot <SPAN class="operator token">=</SPAN> <SPAN class="number token">0.75</SPAN>
Gmax <SPAN class="operator token">=</SPAN> <SPAN class="number token">5.0</SPAN>

<SPAN class="comment token"># path distance parameters</SPAN>
rCost <SPAN class="operator token">=</SPAN> <SPAN class="string token">""</SPAN> <SPAN class="comment token"># use unit</SPAN>
rSurface <SPAN class="operator token">=</SPAN> rDEM
rVertical <SPAN class="operator token">=</SPAN> rDEM
hCostfn <SPAN class="operator token">=</SPAN> r<SPAN class="string token">'C:\GIS\projects\network\potential\hsine.txt'</SPAN>
HF <SPAN class="operator token">=</SPAN> sa<SPAN class="punctuation token">.</SPAN>HfTable<SPAN class="punctuation token">(</SPAN>hCostfn<SPAN class="punctuation token">)</SPAN>
vCostfn <SPAN class="operator token">=</SPAN> r<SPAN class="string token">'C:\GIS\projects\network\potential\vertical3.txt'</SPAN>
VF <SPAN class="operator token">=</SPAN> sa<SPAN class="punctuation token">.</SPAN>VfTable<SPAN class="punctuation token">(</SPAN>vCostfn<SPAN class="punctuation token">)</SPAN>
maxDist <SPAN class="operator token">=</SPAN> <SPAN class="string token">""</SPAN>
nbrfn <SPAN class="operator token">=</SPAN> r<SPAN class="string token">'C:\GIS\projects\network\potential\expd.txt'</SPAN>

<SPAN class="comment token">#Set geoprocessing environmental preferences</SPAN>
arcpy<SPAN class="punctuation token">.</SPAN>env<SPAN class="punctuation token">.</SPAN>extent <SPAN class="operator token">=</SPAN> rDEM<SPAN class="punctuation token">.</SPAN>extent
arcpy<SPAN class="punctuation token">.</SPAN>env<SPAN class="punctuation token">.</SPAN>cellSize <SPAN class="operator token">=</SPAN> rDEM<SPAN class="punctuation token">.</SPAN>meanCellHeight
arcpy<SPAN class="punctuation token">.</SPAN>env<SPAN class="punctuation token">.</SPAN>overwriteOutput<SPAN class="operator token">=</SPAN> <SPAN class="token boolean">True</SPAN>

<SPAN class="comment token"># INITIAL CONDITIONS</SPAN>
rTPot <SPAN class="operator token">=</SPAN> rDEM <SPAN class="operator token">/</SPAN> rDEM<SPAN class="punctuation token">.</SPAN>maximum
rDirRel <SPAN class="operator token">=</SPAN> rTPot
rG0 <SPAN class="operator token">=</SPAN> sa<SPAN class="punctuation token">.</SPAN>CreateConstantRaster<SPAN class="punctuation token">(</SPAN><SPAN class="number token">0.0</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'FLOAT'</SPAN><SPAN class="punctuation token">,</SPAN> arcpy<SPAN class="punctuation token">.</SPAN>env<SPAN class="punctuation token">.</SPAN>cellSize<SPAN class="punctuation token">,</SPAN> arcpy<SPAN class="punctuation token">.</SPAN>env<SPAN class="punctuation token">.</SPAN>extent<SPAN class="punctuation token">)</SPAN>
rGmax <SPAN class="operator token">=</SPAN> sa<SPAN class="punctuation token">.</SPAN>CreateConstantRaster<SPAN class="punctuation token">(</SPAN>Gmax<SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'FLOAT'</SPAN><SPAN class="punctuation token">,</SPAN> arcpy<SPAN class="punctuation token">.</SPAN>env<SPAN class="punctuation token">.</SPAN>cellSize<SPAN class="punctuation token">,</SPAN> arcpy<SPAN class="punctuation token">.</SPAN>env<SPAN class="punctuation token">.</SPAN>extent<SPAN class="punctuation token">)</SPAN>
rGt_1 <SPAN class="operator token">=</SPAN> sa<SPAN class="punctuation token">.</SPAN>CreateConstantRaster<SPAN class="punctuation token">(</SPAN><SPAN class="number token">0.0</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'FLOAT'</SPAN><SPAN class="punctuation token">,</SPAN> arcpy<SPAN class="punctuation token">.</SPAN>env<SPAN class="punctuation token">.</SPAN>cellSize<SPAN class="punctuation token">,</SPAN> arcpy<SPAN class="punctuation token">.</SPAN>env<SPAN class="punctuation token">.</SPAN>extent<SPAN class="punctuation token">)</SPAN>

<SPAN class="comment token"># sample sequence</SPAN>
pthseq <SPAN class="operator token">=</SPAN> list<SPAN class="punctuation token">(</SPAN>range<SPAN class="punctuation token">(</SPAN><SPAN class="number token">11</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">)</SPAN>

<SPAN class="comment token"># create a feature layer</SPAN>
mng<SPAN class="punctuation token">.</SPAN>MakeFeatureLayer<SPAN class="punctuation token">(</SPAN>shpFeat<SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'lyr'</SPAN><SPAN class="punctuation token">)</SPAN>

<SPAN class="comment token"># MAIN</SPAN>
<SPAN class="keyword token">for</SPAN> o<SPAN class="punctuation token">,</SPAN>d <SPAN class="keyword token">in</SPAN> zip<SPAN class="punctuation token">(</SPAN>pthseq<SPAN class="punctuation token">[</SPAN><SPAN class="punctuation token">:</SPAN><SPAN class="operator token">-</SPAN><SPAN class="number token">1</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">,</SPAN> pthseq<SPAN class="punctuation token">[</SPAN><SPAN class="number token">1</SPAN><SPAN class="punctuation token">:</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>

&nbsp;&nbsp;&nbsp; <SPAN class="comment token"># lambda direction</SPAN>
&nbsp;&nbsp;&nbsp; rDir <SPAN class="operator token">=</SPAN> sa<SPAN class="punctuation token">.</SPAN>Aspect<SPAN class="punctuation token">(</SPAN>rDirRel<SPAN class="punctuation token">)</SPAN>

&nbsp;&nbsp;&nbsp; <SPAN class="comment token"># CALCULATE PATH</SPAN>
&nbsp;&nbsp;&nbsp; 
&nbsp;&nbsp;&nbsp; mng<SPAN class="punctuation token">.</SPAN>SelectLayerByAttribute<SPAN class="punctuation token">(</SPAN><SPAN class="string token">'lyr'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">"NEW_SELECTION"</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">' "Id" = '</SPAN><SPAN class="operator token">+</SPAN>str<SPAN class="punctuation token">(</SPAN>o<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">)</SPAN> <SPAN class="comment token"># origin</SPAN>

&nbsp;&nbsp;&nbsp; <SPAN class="comment token"># accumulated cost surface</SPAN>
&nbsp;&nbsp;&nbsp; rAcs<SPAN class="operator token">=</SPAN> sa<SPAN class="punctuation token">.</SPAN>PathDistance<SPAN class="punctuation token">(</SPAN><SPAN class="string token">'lyr'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">""</SPAN><SPAN class="punctuation token">,</SPAN> rSurface<SPAN class="punctuation token">,</SPAN> rDir<SPAN class="punctuation token">,</SPAN> HF<SPAN class="punctuation token">,</SPAN> rVertical<SPAN class="punctuation token">,</SPAN> VF<SPAN class="punctuation token">,</SPAN> <SPAN class="string token">""</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'rBL.tif'</SPAN><SPAN class="punctuation token">)</SPAN>

&nbsp;&nbsp;&nbsp; mng<SPAN class="punctuation token">.</SPAN>SelectLayerByAttribute<SPAN class="punctuation token">(</SPAN><SPAN class="string token">'lyr'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">"NEW_SELECTION"</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">' "Id" = '</SPAN><SPAN class="operator token">+</SPAN>str<SPAN class="punctuation token">(</SPAN>d<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">)</SPAN> <SPAN class="comment token"># destination</SPAN>

&nbsp;&nbsp;&nbsp; <SPAN class="comment token"># path</SPAN>
&nbsp;&nbsp;&nbsp; rPath <SPAN class="operator token">=</SPAN> sa<SPAN class="punctuation token">.</SPAN>CostPath<SPAN class="punctuation token">(</SPAN><SPAN class="string token">'lyr'</SPAN><SPAN class="punctuation token">,</SPAN> rAcs<SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'rBL.tif'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">"EACH_CELL"</SPAN><SPAN class="punctuation token">)</SPAN>
&nbsp;&nbsp;&nbsp; rPath <SPAN class="operator token">=</SPAN> sa<SPAN class="punctuation token">.</SPAN>Con<SPAN class="punctuation token">(</SPAN>sa<SPAN class="punctuation token">.</SPAN>IsNull<SPAN class="punctuation token">(</SPAN>rPath<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">0</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">1</SPAN><SPAN class="punctuation token">)</SPAN>
&nbsp;&nbsp;&nbsp; pathFn <SPAN class="operator token">=</SPAN> <SPAN class="string token">'path'</SPAN><SPAN class="operator token">+</SPAN>str<SPAN class="punctuation token">(</SPAN>o<SPAN class="punctuation token">)</SPAN><SPAN class="operator token">+</SPAN><SPAN class="string token">'_'</SPAN><SPAN class="operator token">+</SPAN>str<SPAN class="punctuation token">(</SPAN>d<SPAN class="punctuation token">)</SPAN><SPAN class="operator token">+</SPAN><SPAN class="string token">'.tif'</SPAN>
&nbsp;&nbsp;&nbsp; rPath<SPAN class="punctuation token">.</SPAN>save<SPAN class="punctuation token">(</SPAN>pathFn<SPAN class="punctuation token">)</SPAN>

&nbsp;&nbsp;&nbsp; rW <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">(</SPAN>rG0 <SPAN class="operator token">-</SPAN> rGt_1<SPAN class="punctuation token">)</SPAN> <SPAN class="operator token">*</SPAN> wFactor
&nbsp;&nbsp;&nbsp; rMark <SPAN class="operator token">=</SPAN> rPath <SPAN class="operator token">*</SPAN> <SPAN class="punctuation token">(</SPAN><SPAN class="number token">1.0</SPAN> <SPAN class="operator token">-</SPAN> <SPAN class="punctuation token">(</SPAN>rGt_1 <SPAN class="operator token">/</SPAN> rGmax<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">)</SPAN> <SPAN class="operator token">*</SPAN> I
&nbsp;&nbsp;&nbsp; rGt <SPAN class="operator token">=</SPAN> rGt_1 <SPAN class="operator token">+</SPAN> rW <SPAN class="operator token">+</SPAN> rMark
&nbsp;&nbsp;&nbsp; rGt<SPAN class="punctuation token">.</SPAN>save<SPAN class="punctuation token">(</SPAN><SPAN class="string token">'rGt.tif'</SPAN><SPAN class="punctuation token">)</SPAN>

&nbsp;&nbsp;&nbsp; <SPAN class="comment token"># DECAY</SPAN>
&nbsp;&nbsp;&nbsp; rPthPot <SPAN class="operator token">=</SPAN> sa<SPAN class="punctuation token">.</SPAN>FocalStatistics<SPAN class="punctuation token">(</SPAN>rGt<SPAN class="punctuation token">,</SPAN> sa<SPAN class="punctuation token">.</SPAN>NbrWeight<SPAN class="punctuation token">(</SPAN>nbrfn<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">,</SPAN><SPAN class="string token">'SUM'</SPAN><SPAN class="punctuation token">)</SPAN>
&nbsp;&nbsp;&nbsp; rPthPot <SPAN class="operator token">=</SPAN> rPthPot<SPAN class="punctuation token">.</SPAN>maximum <SPAN class="operator token">-</SPAN> rPthPot
&nbsp;&nbsp;&nbsp; rPthPot <SPAN class="operator token">=</SPAN> rPthPot <SPAN class="operator token">/</SPAN> rPthPot<SPAN class="punctuation token">.</SPAN>maximum

&nbsp;&nbsp;&nbsp; <SPAN class="comment token"># Update directional relation</SPAN>
&nbsp;&nbsp;&nbsp; rDirRel <SPAN class="operator token">=</SPAN> rPthPot <SPAN class="operator token">*</SPAN> wPthPot <SPAN class="operator token">+</SPAN> rTPot <SPAN class="operator token">*</SPAN> <SPAN class="punctuation token">(</SPAN><SPAN class="number token">1.0</SPAN> <SPAN class="operator token">-</SPAN> wPthPot<SPAN class="punctuation token">)</SPAN>‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

&nbsp;&nbsp;&nbsp; <SPAN class="comment token"># Update rGt_1&nbsp; *** missing earlier ***&nbsp; </SPAN>
&nbsp;&nbsp;&nbsp; rGt_1 <SPAN class="operator token">=</SPAN> rGt<SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

Overall, I get very weird behavior. Some times, it will fail when trying to generate the backlink. In other occasions, it will calculate the first path and then fail. It will calculate three paths and fail. Only once it has ran through the entire sequence. After crashing I make sure to delete all possible files (usually the backlink file is created but it is corrupted).

I have tried many things:

1. Creating a fresh feature layer and erasing it at the end of each iteration.

2. Generating with each iteration different feature layers, one for the origin and another for the destination, and deleting them after each iteration.

3. I have tried saving to the disk the layer feature as well as all the other rasters (I set arcpy to overwrite).

4. I have tried saving to the disk the backlink

5. I have used relative and absolute filenames.

6. I am using only .tif files

7. I have use try...except to catch information about the error with no success

I have spent much time reading through the different forums, etc. I know there were problems with this method in previous iterations of the software. The lack of any feedback relating to possible errors is a real problem! Often it will be python that crashes all together. It is very finicky, there are certain Horizontal Factor settings (even those found in the help pages) that will not generate a complete cost accumulation raster. This is not my case though.

My question is whether there is something that I am missing, something that needs to be reset or deleted? or perhaps someone can suggest how to find more information after the procedure fails???

thank you,

Marc

pathdistance.zip

Find more posts tagged with

Accepted answers

All comments

MLLO

@Xander and Dan_Patterson‌ Did any of you manage to get this to work?

XanderBakker

HI mllo1 ,

The error you mention with the focal stats is the first I hear about it. I had not had that occur to me before. I double checked that file in notepad (I wrote a program to generate it) so I am mystified as to why it might be problematic (it seems to follow esri specs).

The kernel you shared looks perfectly normal, so maybe the error was due to my version 10.3 that I have at home. Will try later using 10.5, or maybe change something in my regional settings that might be causing it. Thanks for the functional explanation.

MLLO

thanks Dan_Patterson‌ the costs are actually generated via the vertical factor (ie. they are simply a function of the slope)

DanPatterson_Retired

I am very familiar with how it works, which is why I was wondering what the raster of nodata's were. I perhaps erroneously assumed that you were including other 'costs' into the analysis other than those associated with a dem... my bad

MLLO

Thanks Xander Bakker,

The error you mention with the focal stats is the first I hear about it. I had not had that occur to me before. I double checked that file in notepad (I wrote a program to generate it) so I am mystified as to why it might be problematic (it seems to follow esri specs).

The script is meant to simulate primarily the effect that an existing path may have on later paths. This effect is accumulative (meaning that previous paths may affect later paths. The bit of code that you include, refers to different aspects of the simulation. rW is a kind of a 'back to initial condition' factor. With each new path, those locations that are not marked again (i.e. cells where the new path does not cross) with eventually restore to their initial condition (g0... zero in this case) the speed at which they do this will depend on the number of paths to be generated (in this case 0.2,... after 5 paths). rMark describes the impact (I) a new path has. This impact, however, is not unbounded, hence, it cannot exceed a certain maximum amount (Gmax). rGt describes the combined effect that all paths may have. It is updated by the presence of a new path. Keep in mind that after a new path is created, the path is reclassified into (1-path, 0-no path), i.e. there are no NoData cells.

Because of some of your comments I did look over the code and realized that I mistakenly omitted one important line (probably because I was trying to figure out some earlier errors). I have now included this at the very end of the script (I also made a comment). This may help to clarify a bit more the simulation.

As for the comments by Dan Patterson. Not certain I understand your comments. There is no cost surface because PathDistance does not require any (by default it uses 1, see How the path distance tools work—Help | ArcGIS Desktop ). As for the vertical and horizontal factors, I have included both files in the zip file and in the explanation (a simple plot XY shows how these are defined). Unfortunately, I cannot use CostDistance as it does not allow you to specify 'in_horizontal_raster' (see Path Distance—Help | ArcGIS Desktop ) .

DanPatterson_Retired

Interesting... how can the raster contain all Nodata cells... it is a complete barrier to movement. Before this was discovered, were any optional parameters specified?

Perhaps what is needed is a description of how the cost surface was constructed, how slope and/or aspect fits into the picture, an origin and destination point sample, then run a simple Cost Distance on that prior to moving on to Path Distance (see how path distance works discussion) since there is no mention of even using horizontal or vertical factors.

XanderBakker

So I tried to run the code and a number of errors occurred. The first one was with the Focal Statistics using the weight kernel from the file EXPD.TXT. Although it seems perfectly OK, it throws an error:

To be sure it wasn't any problem with the path I changed the location of the file, but with no luck:

The overwrite setting is not working very well, since when running the code again it tells me this:

I had to close my IDE to be able to delete the previous files. So I decided to throw in a different Focal Statistics operation, which is obviously not the same, but something the allows the code to continue:

rPthPot <SPAN class="operator token">=</SPAN> sa<SPAN class="punctuation token">.</SPAN>FocalStatistics<SPAN class="punctuation token">(</SPAN>rGt<SPAN class="punctuation token">,</SPAN> sa<SPAN class="punctuation token">.</SPAN>NbrCircle<SPAN class="punctuation token">(</SPAN><SPAN class="number token">20</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'CELL'</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'MEAN'</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'DATA'</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="line-numbers-rows"><SPAN>‍</SPAN></SPAN>

The additional DATA parameter might be good to include in your code to reduce NoData values in the output. After this the code continued, but returned another error:

While inspecting "rPthPot.maximum" I noticed that the entire raster contains NoData values. So I went back and tried to trace where that raster is based on. When I look at this parte of the code:

&nbsp;&nbsp;&nbsp; rW <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">(</SPAN>rG0 <SPAN class="operator token">-</SPAN> rGt_1<SPAN class="punctuation token">)</SPAN> <SPAN class="operator token">*</SPAN> wFactor&nbsp; <SPAN class="comment token"># (0 - 0) * 0.2 = 0</SPAN>
&nbsp;&nbsp;&nbsp; rMark <SPAN class="operator token">=</SPAN> rPath <SPAN class="operator token">*</SPAN> <SPAN class="punctuation token">(</SPAN><SPAN class="number token">1.0</SPAN> <SPAN class="operator token">-</SPAN> <SPAN class="punctuation token">(</SPAN>rGt_1 <SPAN class="operator token">/</SPAN> rGmax<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">)</SPAN> <SPAN class="operator token">*</SPAN> I&nbsp; <SPAN class="comment token"># 1 * (1-(0/5)) * 4 = 4 or 0</SPAN>
&nbsp;&nbsp;&nbsp; rGt <SPAN class="operator token">=</SPAN> rGt_1 <SPAN class="operator token">+</SPAN> rW <SPAN class="operator token">+</SPAN> rMark&nbsp; <SPAN class="comment token"># 0 + 0 + 4 or 0 = 4 o 0</SPAN>
&nbsp;&nbsp;&nbsp; rGt<SPAN class="punctuation token">.</SPAN>save<SPAN class="punctuation token">(</SPAN><SPAN class="string token">'rGt.tif'</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

You can see that rW is always 0 and rGt_1 is 0, so rGt is actually rMark and that raster contains value 4 for the route and value 0 for all other pixels. When this raster is used in the calculation it yields an error since it expects a raster or layer and None does not comply to that, since rPthPot.maximum is None.

I switch off that part in case the rPthPot.maximum is None and let the code run again and this time it finished the first iteration but came up with this error:

The raster contains all NoData cells and can't be used for the Path Distance. So maybe you can functionally describe what you are trying to do, since there are a number of things in the code that don't make sense to me.

MLLO

When pasting the code all indentation was lost. So I manually had to indent using spaces. I am happy to share the data (it is just for testing) but I am not familiar with the procedure to post it. If you let me know how to do that I will.

NeilAyres

And, please a full description of the input Dem. Is it in projected space?

XanderBakker

Hi Marcos Llobera ,

Thanks for sharing the code, that helps, but I am wondering... is this really the code you used? I'm asking since lines 11, 12 and 13 are missing an indentation and line 80 still has a space between "sa." and "CostPath".

It will really be necessary to have access to the data you are using, in the first place to help understand the code and in the second place to see if strange behavior might be related to the data.It is weird though that running the same code on the same data has different results (crashes).

Dan Patterson , don't go, you will miss out on all the fun.

DanPatterson_Retired

Xander... I will leave it to you now that the script has appeared

MLLO

Just reposted the script.

MLLO

Thanks Xander... I will repost with all the script and the data. keep tuned

XanderBakker

I think first it would be best to share the entire script, since the error may be caused somewhere else. Also when sharing code use instructions like those described here: Posting code with Syntax Highlighting on GeoNet

I just copied you snippet of code and several syntax errors occurred:

there is an additional quote on this line:
- rAcs= arcpy.PathDistance_spatial('lyr', rCost, rSurface , rDir, HF, rVertical, VF, '"", 'BL.tif')
a space between the arcpy. and CostPath:
- rPath = arcpy. CostPath_spatial('lyr', rAcs, 'BL.tif', "EACH_CELL")

I'm sure those are not the errors that are causing your problems (since the code would not execute with those errors) but it is important to understand that it will make it much more difficult to help in case you don't share the actual code.

In case possible, share a part of your data too so we can see if the error or any strange behavior can be reproduced.

MLLO

Yes... correct I did not include the rest of the code. Up to this point it had to do with several settings. Everything runs fine up to there (I have check this several times) it is only when I get into the loop that I encounter the behavior I described. Some times it runs fine other it does not.

Could you elaborate on what you mean that 'Global settings in arcmap need nor persist...'. Presumably if I define environmental and set overwrite to True within a script, those will be preserved,no?

DanPatterson_Retired

So to clarify, there are parts of your script not present? Global settings in arcmap need nor persist even within a session.

MLLO

Thanks,

Indeed, all of that was done previously. All environmental variables and working directories were set up before creating anything or making any selection.

DanPatterson_Retired

Your script doesn't set any environment factors such as extent, cell size, snap raster etc. Try to explicitly set those prior to working with rasters to remove the potential for erratic behaviour, particularly if you are experiencing it between runs of the same code.

Join the Conversation

Signed in members can post, follow updates, and more. New here? Register a free account.

Quick Links

Community Help
Find useful guides, FAQs, and documents to help you navigate and make the most of Esri Community.