Hi, colleagues, I am learning the ArcGIS spatial analyst. I have some problems. My questions are listed as below. 1. What is the difference between the layer file with ???end to end blue arrows??? icon and the the layer file with the yellow diamond icon? 2. What is the format of the layer files with ???end to end blue arrows??? icon? 3. Is the format of the layer files with a yellow diamond icon .lyr? 4. Should I select the layer file (e.g. elevation) with ???end to end blue arrows??? icon or layer file with yellow diamond icon? 5. I would like to calculate the least cost distances (LCD) between more than two points, however the ???Spatial Analyst Tutorial??? provides the workflow for only two points (the final site and destination in Stowe.gdb). Can you tell me the complete workflow for calculating the LCDs among more than two points (see, among the five schools in the tutorial)? Attached please find the model I made. Thanks
1. What is the difference between the layer file with �??end to end blue arrows�?? icon and the the layer file with the yellow diamond icon? 2. What is the format of the layer files with �??end to end blue arrows�?? icon? 3. Is the format of the layer files with a yellow diamond icon .lyr? 4. Should I select the layer file (e.g. elevation) with �??end to end blue arrows�?? icon or layer file with yellow diamond icon?
Data variables are shown with the Model Variable icon (what you refer to as 'end to end blue arrows'), and layers from the ArcMap table of contents are shown with the Layer icon ('yellow diamond icon'). In your case they both refer to the same data source, but in order to avoid adding the same layer twice as a different variable, you should use the Model Variable icon ('end to end blue arrows').
5. I would like to calculate the least cost distances (LCD) between more than two points, however the �??Spatial Analyst Tutorial�?? provides the workflow for only two points (the final site and destination in Stowe.gdb). Can you tell me the complete workflow for calculating the LCDs among more than two points (see, among the five schools in the tutorial)?
If there are multiple cells or zones as input destinations, the least-cost path can be calculated from each cell (resulting in multiple paths, one path for each cell), each zone (one path from each zone), or by layer (only one path, the cheapest from any zone). A parameter in the tool specifies which process should be utilized. Source: http://resources.arcgis.com/en/help/main/10.2/index.html#//009z00000021000000
So in short: The Cost Distance will create a accessibility from 1 or more sources The Cost Path will calculate the path from 1 or more destinations back to the best accessible source
Thank you very much for your reply. Your instructions are very useful and helpful to me. I'll practice according to your instructions. Thanks again.
Best regards,
Xiaochen
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Hi,
Data variables are shown with the Model Variable icon (what you refer to as 'end to end blue arrows'), and layers from the ArcMap table of contents are shown with the Layer icon ('yellow diamond icon'). In your case they both refer to the same data source, but in order to avoid adding the same layer twice as a different variable, you should use the Model Variable icon ('end to end blue arrows').
If there are multiple cells or zones as input destinations, the least-cost path can be calculated from each cell (resulting in multiple paths, one path for each cell), each zone (one path from each zone), or by layer (only one path, the cheapest from any zone). A parameter in the tool specifies which process should be utilized. Source: http://resources.arcgis.com/en/help/main/10.2/index.html#//009z00000021000000
So in short: The Cost Distance will create a accessibility from 1 or more sources The Cost Path will calculate the path from 1 or more destinations back to the best accessible source
Hi Xander, along these same lines, do you know how to run a least cost path between multiple points that results in a pairwise least cost path for all points?
So, if you have 5 points, you would have 10 paths?
Hi Xander, along these same lines, do you know how to run a least cost path between multiple points that results in a pairwise least cost path for all points?
So, if you have 5 points, you would have 10 paths?
Thanks, Stephanie Garvis
Hi Stephanie,
If you would like to calculate from a set of 5 points the least cost path between each pair of points, you shoud create cost distance rasters for each point. So we're talking about 1 calculation for each point (5 in total). Then for point 1 you take the cost distance raster and the 4 other points to calculate the 4 paths. For point number 2 you take points 3, 4 and 5 and calculate the paths. For point number 3 take points 4 and 5 en for point 4 take point 5. I do not see a faster way since to determine the path to a source you will need the cost distance raster specifically for that source.
If you would like to calculate from a set of 5 points the least cost path between each pair of points, you shoud create cost distance rasters for each point. So we're talking about 1 calculation for each point (5 in total). Then for point 1 you take the cost distance raster and the 4 other points to calculate the 4 paths. For point number 2 you take points 3, 4 and 5 and calculate the paths. For point number 3 take points 4 and 5 en for point 4 take point 5. I do not see a faster way since to determine the path to a source you will need the cost distance raster specifically for that source.
