Questions tagged [spatial-analyst]
Spatial Analyst is an extension within ArcGIS that provides a range of spatial modeling and analysis tools.
193
questions
2
votes
2
answers
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views
Tobler's hiking function in PathDistance ArcGIS 10.3.1
I am working on least cost paths for an archaeological project and I am trying to implement Tobler’s hiking function on ArcGIS 10.3.1 for Desktop.
I am using SRTM 1 arc second global downloaded on ...
- 37
10
votes
4
answers
34k
views
Filling NoData gaps in raster using ArcGIS Desktop?
I have a raster with gaps in it. I want to fill these in with averages of surrounding cells using ArcGIS 10.2 for Desktop.
I have tried "Focal Statistics" but it averages EVERY cell and not just the ...
- 101
6
votes
3
answers
2k
views
Clustering neighboring points inside ArcGIS Desktop?
I am using ArcGIS Desktop 10x.
I have a shapefile of 300 points which I need to make groups, each of which will contain exactly 9 points which are closest neighbors.
I tried the 'near' tool, which ...
- 785
31
votes
7
answers
19k
views
Methodology for creating accurate drainage networks (and catchments) from high resolution LiDAR DEM?
This is not the first time I've stumbled over this issue; it seems that I am unable to generate a correct drainage network model and the resulting catchments from full resolution (1m cells) LiDAR data....
- 20.4k
10
votes
3
answers
12k
views
Finding nearest raster cell value based on vector point?
I have two layers in ArcGIS: One is a vector point and the other is a raster layer. I want to append the value of the raster data grid to the vector point. The problem is the vector point is away from ...
- 2,215
30
votes
6
answers
22k
views
Ways to Speed Up Python Scripts Running As ArcGIS Tools [closed]
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 ...
- 4,387
25
votes
3
answers
48k
views
Merging multiple SpatialPolygonDataFrames into 1 SPDF in R?
I have created 2 polygons in QGIS. Using them in R, polygons become automatically SpatialPolygonsDataFrame (SPDF). I would like to merge them into single SPDF (as is super easy in ArcGis using Tool ...
- 3,376
14
votes
3
answers
12k
views
Finding locations of highest values in raster using ArcGIS Desktop?
Using ArcGIS 10, I have a raster where I would like to find the pixel with the maximum value in the raster and return its location (center of pixel) in decimal degrees. I would like to iterate through ...
- 165
12
votes
2
answers
53k
views
Creating DEM from contours using ArcGIS Desktop?
I have a large set of contours that I received broken down into several different subsets. I have merged most of the subsets together creating a larger set of contours in three different files. I have ...
- 239
6
votes
2
answers
11k
views
Thiessen Polygon delineation within a Feature
I am trying to create Thiessen (Voronoi) polygons, based on points within a defined shapefile extent.
The output should be inclusive to the feature. The output I receive now is the rectangular area ...
- 128
3
votes
1
answer
6k
views
Why does Raster Calculator (RasterCalculator_sa) give ERROR 000539 in ArcPy?
I am getting a not executed error for a raster calculator. Here is part of the output:
File "C:\projectTemp\FloodAnalysis\floodxsectionanalysis.py", line
107, in makeSeemless
arcpy....
- 191
1
vote
1
answer
10k
views
Using Loop with Raster Calculator in ArcPy?
I am trying to loop through multiple rasters and extract cells that are above 0.1 The code I am trying to use is:
import arcpy
arcpy.CheckOutExtension('Spatial')
arcpy.env.workspace=r'F:\Sheyenne\...
- 101
1
vote
1
answer
904
views
What is the definition of pt_spacing on Point File Information tool?
I can't find any definition for the outputs of Point File Information tool (3D analyst), specifically the pt_spacing field.
Is this the average distance between points, or the average number of ...
- 44
1
vote
1
answer
639
views
Identifying row and column location of a raster image using ArcGIS 10.1
The solution already available online gives a python syntax error
ERROR 000989
Python syntax error: Parsing error SyntaxError: invalid syntax (line
1)
when I write
$$rowmap + 1
in map ...
- 11
1
vote
3
answers
3k
views
Getting latitude and longitude raster from DEM using ArcGIS Desktop?
Could anyone provide with a way to calculate latitude and longitude from DEM, for each raster cell?
In previous posts about this, I have seen that some suggest calculating lat and long in certain ...
- 1,460
17
votes
2
answers
11k
views
Seeking QGIS equivalent to Focal Statistics of ArcGIS Spatial Analyst?
I'm attempting to use QGIS v2.0.1 to accomplish the same tasks that I can do using ArcMap v10.1 and I'm running into some trouble finding equivalent tools. In ArcMap I am using the Focal Statistics (...
- 253
11
votes
2
answers
8k
views
How to calculate stream order for vector data without a DEM? [closed]
I have a shapefile which contains the streams that were digitized from a satellite Image. I would like to calculate the stream order for this data. The data does not exactly match the DEM that I have, ...
- 41.5k
9
votes
2
answers
9k
views
Specifying field in attribute table with raster calculator using ArcMap
How can I specify the attribute field to use in the raster calculator of ArcMap 10.2?
In 9.x, I used the dot notation.
i.e. To use the "New_Value" field, I could do the following:
[MyRaster]....
- 1,445
8
votes
4
answers
19k
views
General steps to create watershed boundary in ArcGIS Spatial Analyst?
I am an ArcGIS beginner.
I have a CD of GIS files of a city and intend to work on watershed management.
There are different file names in different formats on CD. Like .shp, .shx, .dbf, .sbx. and ...
- 83
7
votes
1
answer
14k
views
Converting points to raster in ArcGIS?
How do I create such map from point data?
I am using ArcGIS 9.3 and 10
- 1,188
7
votes
1
answer
2k
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 ...
- 439
6
votes
4
answers
3k
views
Some zones disappear when running Zonal Statistics as Table in ArcGIS
I'm new to GIS. I want the sum of nighttime lights (DMSP) by district for some country. I'm running this arcpy.gp.ZonalStatisticsAsTable_sa(Limites_distritales, "IDDIST", rc, temp_table, "DATA", "") ...
6
votes
2
answers
4k
views
Zonal statistics for millions of overlapping polygons in ArcPy?
I am running ArcGIS 10.1 with 64-bit GP on Windows 8.1 x64.
I want to calculate the zonal statistics of buffer polygons based on parcels and a kernel density raster. The 4.7 million polygons overlap ...
- 837
9
votes
5
answers
35k
views
Converting raster file from float to integer type in ArcGIS for Desktop?
I have a float type raster file (an NDVI made from ERDAS IMAGINE) and would like to convert it to an interger type raster file in order to use Focal Statistics function (Majority). Is there any way to ...
- 111
8
votes
1
answer
8k
views
RMSE between two rasters step-by-step
Can anyone show how to calculate the RMSE (root mean square error) between following two rasters step-by-step and discuss on the obtained results' min and max values, and how to interpret them.
...
opl
8
votes
2
answers
4k
views
Creating point at highest value in raster using ArcGIS Desktop
I am using ArcGIS Desktop 10.1.
I am trying to find the location of the highest value pixel in my Direct Solar Radiation Raster. I can see the extent of the data in my raster but don't know where ...
- 869
7
votes
3
answers
8k
views
Reclassify raster values of 9999 to NoData, leaving all other values alone, in ArcGIS Desktop?
I have a raster in ArcGIS which has a number of cells with the values 9999, showing that the data could not be generated for that cell. I want to convert all of these 9999 values to NoData, so that ...
- 4,004
6
votes
2
answers
5k
views
Calculating zonal statistics of raster data in multiple overlapping zones and combining them into one table
The aim here is to calculate the max, min, mean, range, sum, count and std of raster data contained in areas delimited by polygons (much like what the Zonal Statistics as a Table tool from Spatial ...
- 187
6
votes
1
answer
985
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 ...
- 2,343
6
votes
1
answer
2k
views
Does Zonal Statistics value change when applied on subset of data using ArcGIS Spatal Analyst?
I have generated zonal statistics using feature zone data on a value raster. This shapefile contains about 20000 polygons and the analysis went without a hitch.
While testing quality, I ran the same ...
- 388
6
votes
3
answers
2k
views
Using ArcGIS to extend a polygon in one direction up to the edge of another polygon
I have two shapefiles: the first containing a route defined by a single polygon (black line in the image below), the second containing a series of between 1000 and 4000 small polygons located ...
- 181
5
votes
1
answer
2k
views
Conditional reclassification of a raster
I am attempting to do a conditional reclassification of an NLCD land-use raster.
I specifically want to reclassify all developed areas (classifications 22,23,24) that are near a road (classification ...
- 153
5
votes
2
answers
2k
views
Comparing two TINs created using ArcGIS for Desktop?
I have the following two files:
LiDAR las file1
Let's give it a name LiDAR las file2, contains the same file1 data, where number of points randomly removed.
So if file1 contains X number of points, ...
user1769
4
votes
2
answers
6k
views
Accessing Spatial Analyst extension from stand alone script?
If I run this script:
import arcpy
arcpy.AddMessage(arcpy.CheckExtension("Spatial"))
from arcpy.sa import Con
from arcpy import env
fDir=r'd:\scratch\fdir'
outFolder=r'd:\aerials\images'
env....
- 23.2k
4
votes
1
answer
18k
views
Deleting values from raster file using ArcGIS Raster Calculator?
I have a raster that denotes certain landcover types.
How do I delete all of the pixels except for the ones I want?
I tried going through the symbology tab and while that deletes it for display it ...
- 258
4
votes
1
answer
398
views
Adding and calculating X and Y attributes in integer raster using ArcGIS Spatial Analyst?
I have an integer raster created from an input floating point (LiDAR) raster by multiplying it by the (elevation) value of 100 (any other value higher would not work)
Thus, I can add a "double" ...
- 20.4k
4
votes
1
answer
2k
views
Calculating mean upslope aspect from each cell in DEM using ArcPy?
I am trying to write a python script to calculate the mean aspect upslope from each cell in a DEM. I have the general workflow down, but my final output is restricted to angles between 0 and 90 ...
- 2,105
4
votes
2
answers
1k
views
Extracting peaks from DEM and creating 5 m elevation buffer around each peak in ArcGIS Desktop?
I have a DEM available and would like to identify all the peaks that are likely to be bare rock. I want to be able to isolate these areas and create a 5m elevation buffer around them to represent the ...
user107580
3
votes
1
answer
9k
views
How do you set OFFSETA for a Viewshed in ArcGIS10?
How do I calculate height when attempting to do a viewshed analysis in ArcGIS10?
I am able to create a viewshed analysis from a poly point file, however I need to calculate for the 80ft to 100ft tower ...
- 61
2
votes
3
answers
1k
views
Upslope and downslope distance or area using ArcGIS Desktop?
Is there a possibility to determine the surface area above the road and the surface of the terrain below the road or between two or more roads? I want to pull the trees down the hill and up the hill ...
- 2,407
1
vote
2
answers
625
views
Viewshed Analysis for bridge polyline observer feature
I am using the Viewshed tool in ArcGIS 10.2 to determine the cells from a DEM that are visible from a highway corridor that has a bridge crossing a river (my observation feature). My question is in ...
- 73
14
votes
4
answers
5k
views
Combining corner-touching polygons into a single feature
I have created a polygon layer from rasters, and only have a single classification ID (and calculated acres) for each polygon. I would like to "dissolve" all touching features into larger, individual ...
- 23.2k
10
votes
2
answers
11k
views
Dealing with NoData in ArcGIS Spatial Analyst?
When using Spatial Analyst I regularly have issues with NoData values cropping up in the data.
Various tools appear to introduce NoData values regularly.
These values then cause issues with ...
- 6,127
10
votes
4
answers
5k
views
What Algorithm is used by ArcGIS Watershed tool?
Does anyone know what type of algorithm is used in the ArcGIS Watershed tool (in the Spatial Analyst package)?
Very little information given on Esri's website ... but I suspect it may be some kind of ...
- 2,288
9
votes
1
answer
13k
views
Extracting raster cells from imagery based on RGB value using ArcGIS Desktop?
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 ...
- 526
8
votes
2
answers
14k
views
ArcGIS ERROR 000824: The tool is not licensed in arcpy
I try to run the Zonal Statistic as a Table through ArcPy and it gives me:
ERROR 000824: The tool is not licensed.
Here is the doc for the function: http://resources.arcgis.com/en/help/main/10.1/...
- 141
8
votes
2
answers
9k
views
How get intersection of polygons in the same table by PostGIS?
I have a single table of over 1000 polygons in postgreSQL (with PostGIS), and I have a field "evaluation_type" that only receives two values, either 'good'(green) or 'bad'(red), as you can see in the ...
- 194
7
votes
3
answers
12k
views
Clipping raster using polyline or polygon using ArcGIS Spatial Analyst?
I have a large raster created from values that cover the whole United States and Alaska which are both polygon and polyline features, this raster was caluclated using Spatial Analyst IDW Interpolation....
- 2,125
7
votes
2
answers
7k
views
Round Raster to next higher or lower int
I am using ArcGIS 10.1.
I am searching for a solution to calculate a raster.
The values are like:
0.2
0.6
5.3
i.e.
How can I now get 0.2 as 0 and 0.6 to 1 and 5.3 to 5? In the end integer numbers.
...
- 73
7
votes
2
answers
4k
views
Can shaded relief be "blended" with DEM colour ramp in ArcGIS to produce a more visually dramatic result?
Not being able to use true transparencies with ArcGIS colour ramps where only solid colours are allowed has me always wondering about how to improve the look of the surface in my maps without ...
- 20.4k