combining map data of similar dimension to produce new maps using algebraic operations

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1answer
42 views

Raster Multiplication - Can't Multiply Sequence by Non-Int of Type “Float”

I am trying to multiply a list of GRID raster datasets using a different value for each raster. The value is in the raster name. Some examples are [wse_1979_5,wse_1980_0,wse_1980_5], where 1979_5, ...
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1answer
49 views

How to iterate RGB raster layers in ModelBuilder?

I have an RGB raster that I'm calculating color-based indices from. When I do the calculations manually, I can select a certain band of the RGB raster to calculate. I need to do the same operations on ...
0
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1answer
149 views

NameError: name 'Con' is not defined

I have 365 rasters with the same extent, and I am trying to sum them together by month. I have the script below, which was working until I added the line out1 = Con(IsNull(raster), 0, raster) which is ...
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0answers
24 views

Map algebra from QGIS python console? [duplicate]

What command do I use to do map algebra on rasters from the QGIS python console?
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1answer
270 views

Map Algebra - Grass GIS (r.mapcalc) merge two raster with NoData value

I have a slope raster and a road raster. The black pixels in the road raster are NoData values and the pink pixels have a value of 1. They don't cover exactly the same area. I want to create a new ...
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1answer
107 views

Efficiently check for equal adjacent values in raster calculator

I have a raster consisting of integer values in each cell. I want to check every adjacent cell in a 3x3 grid to see if any one of the adjacent cells has a value EQUAL to the center cell, and if so, ...
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1answer
120 views

Map algebra expression with dynamic raster layers

Attached is the model that i am working on. The "To Value" and "From Value" are model parameters and hence subject to change each time according to requirements, This leads to varying number of ...
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1answer
143 views

Raster produced by Con expression not saving

I cannot get a Con expression to work. Or, if it is working, I cannot get the raster produced by the Con expression to save. I have two rasters and I want the positive difference between the two, and ...
2
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1answer
170 views

Nearest Neighbor Focal Statistics and Map Algebra

I would like to use a nearest-neighbor type analysis to iterate over a raster. The nearest neighbor analysis will give a cell value of 1 IF AND ONLY IF the cell being analyzed has a cell value larger ...
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1answer
590 views

ModelBuilder: How2 pipe output of Iterate Raster tool into Raster Calculator tool?

Re: ArcGIS v10.1 ModelBuilder Hello, THE PROBLEM: Using ModelBuilder and map algebra, I want to compute a ten year average grid from a stack of 10. The problem is that only 1 grid (%raster%), the ...
5
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1answer
272 views

Error using con in Map Algebra in Python script

I am experiencing a painful problem in the middle of a Python script I am writing. When I get to a Map Algebra function, I have tried two different options and both return a different error. At first ...
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2answers
253 views

How to produce a mean raster file based on other raster files? [duplicate]

Possible Duplicate: Tools to flatten the jp2 to a single band (average the bands)? I have a number of raster files from a same area, that coordinates of corresponding pixels perfectly match ...
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0answers
123 views

Map Algebra in VB.NET Add-In Tool

I'm trying to run a map algebra expression in a vb.net add-in, and can't seem to get it to work. It's a roving window that interpolates noData areas in a DEM. The expression works in the Python ...
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2answers
2k views

Using individual bands from a multi-band image in ArcGIS 10 raster calculator

I'm trying to use individual bands from a multi-band TM image (IMG file) within the raster calculator in ArcGIS 10 (SP2/3). I can add individual bands to my MXD, but raster calculator will only use ...
1
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0answers
186 views

How can I ignore NoData values in map algebra? [duplicate]

I need a way to exclude NoData from calculations. I don't want any NoData cells from any of the rasters to be used in pick or con statements.
2
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1answer
460 views

Spatial Analyst tool Look up but in ArcView3.2

Is there any option how to do a Spatial Analyst tool "Look up" operation from ArcGIS 10 in ArcView 3.2? I have a grid with attributes and need to "extract" values from the table field (values from ...
8
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3answers
553 views

How do I create a raster randomly choosing a cell value from 2 or more overlapping rasters?

I'm using Arc 10. I want it to combine multiple rasters into one, always choosing randomly from the values of overlapping cells. I have an image that may explain this better:
3
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1answer
373 views

Change raster value for an area based on a class of another raster

I would like to change all raster values in raster A that fall into the locations of category/class 1 of raster B. Here, some more details. I did a calculation on a DEM resulting in different ...
4
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2answers
2k views

For Loop - Map Algebra (ArcGIS) using Python

ORIGINAL QUESTION Im relatively new to python and these fourms but Im am having trouble utilizing for-loops for spatial analyses within ArcGIS. It does not appear to recognize the variable, ...
3
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4answers
581 views

Compressing map algebra outputs from ArcPy

When creating a raster map algebra output, is it possible to set its compression? I'm creating a model which generates many hundreds of rasters, and currently each is being stored without any ...
7
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1answer
770 views

Partially update a raster (a DEM)

My todays question is: How to update an .img DEM in ArcView 9.3? I do have DEM which need to be updated only if few parts. The area to be updated has been produced in separate DEM with Spline ...
11
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4answers
293 views

What are some Domain Specific Languages (DSLs) for GIS?

I'm curious what sort of domain specific languages (DSLs) are used in GIS. The only one I can think of is the DOCELL language that was provided in ArcInfo Workstation GRID, but is no longer ...
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8answers
2k views

What raster-based GIS systems really work?

Raster GISes like GRASS, ArcGIS/Spatial Analyst, and Idrisi can perform a rich set of data processing and analytical procedures loosely known as "map algebra." In today's computing environment it is ...