Spatial Analyst is a extension within ArcGIS that provides a range of spatial modeling and analysis tools.

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5
votes
1answer
219 views

Sum raster data visible from given point, by proportion of view

I am wondering if there is a tool that does the following (preferably in Arc but other options considered). Simple example: what proportion of the view from a given point on the landscape is occupied ...
4
votes
1answer
222 views

Raster Reclassify fails upon Completion in ArcGIS

When attempting to reclassify a raster in a student edition of ArcInfo 10, the program crashes without an error upon reaching 100%. The reclassified raster is written, but with no spatial info. I've ...
3
votes
2answers
705 views

Majority filter (minimum mapping unit) in ArcGIS Desktop with larger window size?

I want to run the majority filter in ArcGIS Desktop with a window size of 4 or 5 i.e. greater than the default 3. Is it possible, or is there some other command (or tool) which might help me achieve ...
3
votes
2answers
347 views

Create hachures from DEM in ArcGIS 10.1

I have created contour lines from DEM and now I need to create hachures/bergstrich for them. I believe that spatial analyst should solve this, but I'm not used to it and I didint found any similar ...
3
votes
1answer
293 views

Can ArcGIS handle missing values to create a contour map?

I am trying to create a contour map for a waterbody. It turns out that in several locations there is no data. I just don't want to use the missing values as zero in ArcGIS because it would create ...
6
votes
1answer
2k views

How to calculate the flood volume using a LiDAR DEM and a HEC-RAS floodplain polygon

I’ve got a vexing GIS analysis problem which is conceptually fairly straightforward, but in reality more challenging to figure out…. Basically, I need to calculate the VOLUME of floodwater within a ...
6
votes
1answer
760 views

Working around slow processing times in ArcGIS Spatial Analyst functions?

I am batch processing a large amount of distance functions (~50,000) using ArcGIS 9.3. In this version, using spatial analyst functions, it seems to be the case that users cannot parallelize processes ...
8
votes
1answer
636 views

Calculating distance from points to different class in raster

I am looking for some advice on how to calculate the distance from a point to a different class of a raster. Specifically, I have observations (points) of animal use overlaid on land cover data. For ...
2
votes
2answers
522 views

Performing viewshed analysis with ArcGIS Desktop Standard License?

Is there a way to perform a Viewshed Analysis with the Standard license of ArcGIS 10.1 for Desktop? If not, what is the difference (if any) between: Viewshed with (Spatial Analyst)- ...
2
votes
2answers
80 views

How can I create contours of 0.1 or 0.2 instead of 1?

The default value is 1 and I have salinity values from 33 to 35 and therefore only contours 34 and 35 can be created with the contour interval 1... But I want it smaller so I can see contours 34.1, ...
1
vote
1answer
3k views

reclass, raster calculator

I'm trying to apply seperate equations for different land types. I have created a raster containing only the land type I'm interested in. I then reclassed the values to '0'. My plan was to use the ...
9
votes
2answers
1k views

How can I get weighted Flow Accumulation to deal with negative values? [duplicate]

here's one I haven't seen anywhere, to my surprise. I am trying to do something a little different with Flow Accumulation, which I would think has been attempted before, but it's stumping me for now. ...
3
votes
2answers
170 views

Is r.cost equivalent to diffusion interpolation with barriers?

I want to perform interpolation using cost distances rather than euclidean distances similar to Greenberg et al. (2011). In that paper they use r.cost in GRASS to compute cost distances for each ...
2
votes
0answers
168 views

ArcMAP path distance function handling of polygon and raster inputs

I am using a path distance function to calculate distances from a set of source cells on a land use raster. Unfortunately, my land use raster and my other inputs have different cell sizes. The land ...
2
votes
4answers
506 views

Error When Trying to Run Slope Analysis Script

I have written a script which is supposed to loop through all the rasters in a folder and perform a slope analysis on each raster and save the results in another folder. I keep getting the following ...
1
vote
0answers
429 views

Raster calculator error 000539 - cannot create weak reference to 'classobj' object

I was - like many times before - trying to clip a raster with the raster calculator (raster * 1 with shapefiles as mask). Now - the following error keeps popping up: ERROR 000539: Error running ...
-3
votes
1answer
325 views

How to calculate cumulative mean in Arcgis

I'd like to get cumulative mean value from a multiband image (4 bands). How can I do it in Arcgis, ERDAS and ENVI? Thanks in advance
2
votes
0answers
330 views

About zonal statistic function in ARCGIS

I calculated zonal statistic in Arcgis to get max/min value of each LC types. Broadly, LC image include forest, grassland, waterbody etc. But output max value of zonal statistic function give me 0.972 ...
1
vote
1answer
162 views

How can I multiply each band of multiband image by separate scalars?

I have an image with 5 bands. I need to multiply each band of this image by different scalars one time (I'm lazy to do it one by one) and then get multiband image as a output. For example ...
1
vote
0answers
232 views

How to Create Multiple Start and Destination Cost Paths?

I have a suitability matrix which was created in model builder based on elevation data and multiple start data points and end data points representing schools. I'd like to link all the schools up ...
7
votes
3answers
3k views

Extract Overlapping Polygon Data to Points

I have a polygon data set of corn yield collected by a combine. However, as the combine drove through the field, there was slight overlap between passes, leading to overlapping polygons within the ...
3
votes
1answer
330 views

An error in raster calculator in Arcgis

I wrote and ran this formula in raster calculator in ARCGIS. But the following error gets me into trouble. Does anyone have a suggestion to overcome this? Here is the formula I wrote and the error ...
4
votes
4answers
205 views

How to determine if all points on a map are identical in arcpy?

My eventual goal is to automate kernel density calculations for a large corpus of point data; however, if all points are identical (for example, if there are 7 points all stacked on top of one another ...
0
votes
2answers
1k views

Difference between Geostatistical Analyst and Spatial Analyst toolboxes for interpolation?

I did interpolation on point data using "Geostatistical Analyst" tool. It gives me surface layer. Then I exported this layer into raster image (by right click on this layer=>export data into raster) ...
4
votes
0answers
477 views

ArcGIS Kernel Density with polyline, search radius / bandwidth calculation

I'm conducting a density analysis of a series of polylines and I'm hung up on determining an appropriate search radius. The default calculation performed by arcgis is to take the shorter dimension ...
1
vote
0answers
136 views

Spatial Analyst's CostPath toolbox/function has PATHCOST of 0 when using in_memory workspace

I have a point feature and am interested in finding the least cost path between two points in the feature using a raster as the cost surface. I first calculate the cost distance and cost backlink via ...
5
votes
1answer
2k views

Extract Values to Point from Raster Issue

I am trying to use the tool Extract Values to Points on a File Geodatabase raster, but I am getting some weird errors. I've used this tool multiple times before with no issue, but not since I ...
8
votes
1answer
259 views

Are there any rules of thumb for the neighborhood settings in Focal Statistics?

In ArcGIS 10, users can define the neighborhood in the Focal statistics tool. The moving window shape can be set to any of the following: Wedge, annulus, circle, rectangle, irregular, and weight. ...
0
votes
0answers
116 views

Does the Calculation of Spatial Weights Matrix in ArcGIS take into account 3D?

This question is about Spatial Weights Matrix in ArcGIS. Does it take into account 3D or not? I want to calculate Spatial Weights Matrix with SPACE_TIME_WINDOW. Anton
1
vote
1answer
95 views

sa.fill creates NoData raster in standalone script ArcMap 10.0

I am trying to put together a geoprocessing workflow in Python, and I've hit a stumbling block with sa.fill. When run as a standalone script, the tool produces a raster composed entirely of NoData ...
2
votes
1answer
378 views

how to obtain elevation points for a road using contour?

I have contour lines, & roads centerlines feature classes, I need to get points with elevation in the starts, intersections, & the ends of the roads, how can I get this information? I used the ...
1
vote
2answers
107 views

Distribute gridded data to corresponding subbasin boundaries?

I have one ArcGIS shapefile of my river basin consisting of many subbasin. Another shapefile showing the location of gridded points over the whole basin (Its latitude and longitude are used as file ...
2
votes
2answers
471 views

Why does Raster Calculator return GRID ERROR-Unable to open the input grid: 1+FLOATC:\document…?

I'm calculating Simple Ratio (SR) from NDVI using Raster calculator in Arcgis. Here is expression I wrote in Raster calculator. SR=(1+float[NDVI_apr.tif])/(1-float[NDVI_apr.tif]) But when I evaluate ...
3
votes
0answers
396 views

What is the convergence threshold for ArcGIS Iso Cluster?

The ArcGIS tool Iso Cluster Unsupervised Classification does not seem to have any documentation on the convergence threshold used in the tool. To compare, Erdas Imagine has all of the necessary ...
6
votes
3answers
3k views

Extract raster by mask output does not completely overlap the mask

I have a flow accumulation grid and a shapefile containing catchment areas. Now I want to do some calculations on them so I need to extract data from cells in the raster adjacent to certain catchment ...
6
votes
1answer
3k views

ArcMap 10 - Extract raster cells from imagery based on RGB value

I've got some aerial photography (format: IMAGINE Image) which is detailed enough to see to fire hydrants and a shapefile of fire hydrants which was digitized based on some CAD data. My project is to ...
3
votes
2answers
2k views

How to find out the Stream Order from DEM

I have DEM Data for the study area, I want to know how to find out the stream order using DEM. I saw Stream order tool in Hydrology toolset in ArcGIS. in Stream order tool what is input stream raster ...
1
vote
3answers
1k views

How To find the Catchment Area for a Dam?

I have a DEM of my study area, and polyline shapefile of the Dams in that area. I have run the standard Hydrology tools on it( Fill, Flow Direction & Flow Accumulation). I know that you can ...
8
votes
1answer
990 views

Problem analysing movement using cost surfaces (involving ArcGIS's Path Distance-tool)

I would like to analyse hypothetical movement (on foot) in a landscape as based on energy expenditure, but I have run into some trouble that I am hoping that you could help me with. I have tried to do ...
3
votes
0answers
123 views

Which geostatistical tools to use to determine surface changes over 40 years?

I have a data from the Weather station with SWEmax (snow water equivalent) collected over 40 years. I need to interpolate the data over my river's watershed and then, somehow, determine the ...
3
votes
0answers
698 views

Performing a Multicriteria Analysis Using Distance Along a Road Network

There is the possibility that I will be working on a project which will look at thousands of properties in a region and measure their accessibility to different services (schools, parks, hospitals, ...
1
vote
1answer
403 views

GWR Result Issues

I am working with GWR to identify if there are any relationships between 'extreme' events and disease incidence. The use of GWR has been employed because I am working in a region where local ...
0
votes
1answer
2k views

arcpy.RegionGroup fails with error 999999. Workspace or data source is read only

outRegionGrp = RegionGroup(inRaster,"EIGHT", "WITHIN", "ADD_LINK", valToIgnore) arcgisscripting.ExecuteError: ERROR 999999: Error executing function. Workspace or data source is read only. The table ...
6
votes
1answer
354 views

Why does tool take longer to run when in Python script?

I have written a python script that does some euclidean allocation. For that I use arcpy.gp.EucAllocation_sa() method. Now, my python script takes 30-40% extra time than spatial analyst euclidean ...
1
vote
1answer
127 views

Substitute for SpatialJoin tool?

I have to write a script in Arcgis which I would like to use the SpatialJoin tool (arcpy) but I do not have the appropriate extension. It may be a tool (or example of scripts) for doing the same ...
1
vote
1answer
879 views

Modelling Sea level rise scenarios for a Coastal county in ArcGIS

I am a graduate student @ Clemson University and am working on a GIS based project which is to model different sea level rise scenarios and estimate its impacts on a coastal county and to suggest ...
1
vote
2answers
86 views

How to query points that fall outside their designated regions?

I have a shapefile with 250 points. Each point has a region attribute. In another shapefile I have all the possible regions with their names (it is polyline geometry). Unfortunately the coordinates ...
8
votes
1answer
1k views

What type of kernel density function does ArcMap use?

I know that there are several types of kernel density functions, such as uniform, cosine, Gaussian, etc. I was just wondering which one the "Kernel Density" functionality in ArcMap 10's Spatial ...
21
votes
6answers
8k views

Ways to Speed Up Python Scripts Running As ArcGIS Tools

This is a pretty general question. I just wondering what tips and tricks GIS programmers have used to speed up arcpy scripts that you import into the toolbox and run. I work most everyday writing ...
2
votes
2answers
427 views

Why would a perfectly usable raster mosaic produce an unusable clipped raster?

I'm getting funky results from Extract By Mask (spatial analyst). I'm clipping a Raster Mosaic of DEMs from the National Elevation Dataset with polygons. I have a script to run through 15 separate ...