Questions tagged [saga]

SAGA (System for Automated Geoscientific Analyses) is a GIS toolbox with many modules that can be used from the GUI, command line or accessed through R,python or directly using C++.

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0answers
399 views

How to show and access SAGA not shown in Processing Panel in QGIS 2.18.4? [closed]

How to get SAGA modules to show and be usable within QGIS, i.e. from within the Processing Panel? I have tried reinstalling SAGA (now = Version: 2.1.2 64 bit) through the OSGEO4w installer and tried ...
3
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0answers
496 views

Grid Error – Natural neighbour

I am getting the following Error on using Natural neighbour. There were solutions suggested here & here. But these works fine on Windows but not on Ubuntu. I am using Ubuntu 14.04, QGIS 2.18.4 &...
6
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1answer
198 views

Rename outputs from QGIS processing saga algorithms

I have a processing script which chains together several saga processing tools like this: outputs_SAGARASTERCALCULATOR_3=processing.runalg('saga:rastercalculator', inputvx,[inputvy],'(atan2(a,b)) * (...
6
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2answers
1k views

Estimation of volume from DTM

I'm using QGIS for quite a while now but I'm having some problems in measuring the volume of a depression zoned North of a waste dump I'm studying. For the analysis I'm using a recent 1mx1m DTM of ...
5
votes
2answers
639 views

Add Polygon Attributes to Points error QGIS

I am trying to run the Add Polygon Attributes to Points algorithm from the Processing Toolbox in QGIS but I run into an error. All my points are either inside the polygon or exactly on the border. I ...
4
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1answer
852 views

Which interpolation method is used in the close gaps module of Saga GIS?

I like to close gaps in a raster layer using the Module Close Gaps of Saga. I can not find which interpolation method is used by the module. Which method is used by the module and/or where can I find ...
0
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2answers
249 views

SAGA error (Segmentation fault) with running QGIS

--Running with configuration is Mac OS X 10.11.6 (El Capitan), QGIS 2.14.7-Essen, SAGA 2.2.3-- I'm hoping that someone knows what the fix is for the failure I'm encountering in the SAGA tool. I'm ...
2
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0answers
252 views

SAGA Merge Vector Layers 'Add Source Information' not returning correctly

Running "Processing -> Toolbox -> Saga -> Merge vector layers" in QGIS with 'Add source information' checked returns a merged file with an additional attribute "Source" but the values are a series of ...
3
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2answers
925 views

QGIS Sample Points From Raster

I know that QGIS can add values from a raster to a set of points on top of the raster through the SAGA "Add raster values to points" tool. However, I would like to generate the points themselves based ...
3
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1answer
3k views

Variogram model - SAGA on QGIS Processing

QGIS 2.14 (Win) comes with SAGA 2.12, which Ordinary Kriging supports 6 variogram model options. However, if I run SAGA Ordinary Kriging from QGIS Processing Toolbox, there is no drop down menu. Only ...
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6answers
3k views

Problem getting SAGA activated in Ubuntu QGIS 2.18.2

By some reason SAGA does not appear into Processing Toolbox list although I have checked it to be active. See screen capture. What could be the problem? QGIS vesion is 2.18.2 and OS is Ubuntu 16.04 (...
3
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1answer
367 views

DEM classified using SAGA GIS and conversion to point shape

I have converted DEM to terrain specific points i.e. peaks, pits, saddle points etc. with SAGA GIS using surface specific points tools. The output is showing values as 1, 7, 9 -1 etc; with different ...
5
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1answer
6k views

Saga-GIS Mosaic raster layers error: 'NoneType' object has no attribute 'crs'

Trying to merge multiple raster layers (TIFF's) with the same extent with Saga-GIS Mosaic raster layers. The only reason I'm using this Mosiac-thing is because it lets me merge multiple layers (...
5
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2answers
2k views

How to configure QGIS (SAGA, GRASS algorithms) in Ubuntu

I have installed GRASS GIS following this install manual. I have installed SAGA GIS following this install manual. and finally I have installed QGIS 2.18.1 following the official details for ...
4
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1answer
963 views

SAGA grid tools missing in QGIS

Grid options are missing in SAGA toolbox. If I go to options in processing the following message is being displayed. How should I change the path?
5
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1answer
85 views

Why “saga:gridssum” takes 7 input grids instead of 3?

I want to sum the cell values from 3 grids. I have a list of file paths (temp layers) generated in a "for" loop, looking like the following one. I cannot understand why the function makes some ...
1
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0answers
99 views

How to do regression analysis in SAGA for topographic correction

Currently I am trying to do the topographic correction using C-Correction. I would like to know if there is a way to do the regression analysis between L (uncorrected reflectance of each band from ...
6
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1answer
800 views

Flow Path length

I'm a student and pretty much new to QGIS, GRASS and SAGA tools. I'm trying to calculate the longest flow path length using SAGA "flow path length" module in Qgis. Using the default parameters: I'...
1
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1answer
88 views

How to sum values of a grid moving upstream along flow paths in GIS/R?

I would like to sum the values of a grid, moving upstream along flow paths. In other words, I have a grid A with a value for each cell. I need to build a new grid, B, in which the value of each cell ...
4
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1answer
829 views

Color palette SAGA GIS

Does anyone knows if it is possible to manually modify SAGA GIS colour palettes, for example using ColorBrewer references?
1
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0answers
83 views

QGIS mac: Problem running several algorithms from toolbox

I want to use the SAGA algorithm "add coordinates to points", but I get an error message: Algorithmus Add coordinates to points startet... shapes_points "Add Coordinates to points" -INPUT "/var/...
3
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0answers
161 views

Why is 'Line Dissolve' producing different output than 'Dissolve' from Ftools?

I'm curious if anyone can explain the strange effects I'm seeing from the SAGA 'Line Dissolve' tool. I have a ton of line features that had previously been 'exploded' (which is a necessary step), and ...
6
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1answer
761 views

SAGA GIS raster calculator - QGIS scripting gt expression

I am trying to perform a simple raster calculator that takes input rasters and outputs a new raster with a constant value where values exceed a specified number in the input. This is part of of a ...
1
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1answer
177 views

Terrain analysis

I tried running ArcSaga Morphometry python based tool for slope,aspect and curvature but it failed what could be the problem? ......t" # # # # # # # # # # "9 parameter 2nd order polynom (Zevenbergen &...
8
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2answers
2k views

SAGA algorithms not working on Qgis 2.18 on Mac OSX

Since last update to Qgis 2.18 from 2.14, I'm unable to successfully run SAGA algorithms (Mac OSX Yosemite). No matters if it is vector- or raster-oriented algorithm, the algorithm stops at this point ...
2
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1answer
382 views

Why does Accumulated cost fail with 'QgsVectorLayer' object has no attribute 'bandCount'?

When using the function Accumulated cost (isotropic) from the SAGA algorithms in QGIS i get the following error message: An error has occurred while executing Python code: AttributeError: '...
3
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1answer
259 views

How calculate relative heights in SAGA?

I've calculated relative heights in ArcGIS, now I'd like to calculate relative heights (range between maximum and minimum cell value in window 3x3) in SAGA. It's important that I don't want ...
3
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1answer
1k views

How SAGA calulates Convergence Index

I have calculated convergence index on my DEM with SAGA. Output results seems to be ok (values in range -100;100), but I don't understand how it works. Here is some sample data from my DEM: I know ...
2
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1answer
363 views

Calculating curvature in SAGA?

I have calculated curvature using ArcGIS (curvature) and SAGA (Slope, Aspect, Curvature; based on 9 parameter 2nd order polynom (Zevenbergen & Thorne 1987) method), however, the output rasters are ...
8
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4answers
3k views

How to change SAGA path in QGIS 2.18 Standalone

I have installed QGIS 2.18 Standalone (64 Bit) with SAGA GIS (2.1.2) and GRASS GIS 7. Afterwards I have installed the newest SAGA GIS 3.0.0. I want to change the SAGA folder in the processing options,...
1
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1answer
149 views

Calculating land sea area ratio in a portion of raster map in QGIS

I wanted to know how can I calculate land/sea area ratio in a portion of raster map (attached in the mail) Till now i had this raster map that i converted in to vector by the option raster>>conversion>...
5
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1answer
343 views

Getting Output names of Processing algorithms via PyQGIS

Calling the results of Processing algorithms in order to plot them to the screen differs depending on the provider used. An example with QGIS provider: tmpggis = processing.runalg("qgis:...
2
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1answer
458 views

SAGA Upslope Area Calculation from Vector Point Layer resolves in no output and no error message

I'm using the SAGA Upslope Area algorithm within pyqgis, but i'm stranded, since my script doesn't create any output at all. I'm trying to use geometry from points in a vector point layer as input x ...
3
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0answers
242 views

How is ray tracing different from ambient occlusion when hillshading with SAGA?

SAGA offers both raytracing and ambient occlusion in its Analytical Hillshading module, but doesn't explain how these modes differ. Is one significantly more expensive in computation, and is the ...
4
votes
1answer
152 views

SAGA GIS segfaults on launch

I'm having problems with SAGA GIS. It segfaults on launch, either from the command line or when called from QGIS. If I run saga_cmd using gdb, I get this error:- (gdb) run Starting program: /usr/...
1
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0answers
290 views

SAGA_CMD: select polygon features of one shapefile and save in new shape files [closed]

I want to use saga_cmd to select from a shapefile only the shapes, which have a certain area size and store this selection into a new shapefile. I'm using the following command to filter via the ...
1
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0answers
176 views

QGIS for mac acting strange after upgrade to 2.16

I'm running OSX 10.10.5 and just upgraded QGIS from 2.14 to 2.16. 1st. the installed GDAL 2.1 wasn't registering when using gdalinfo --version. It still showed 1.11... So I used MAPBOX GUIDE to get ...
4
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2answers
576 views

Why does saving a big Shapefile take so long?

When trying to save a large (281250 shapes), yet fairly simple shapefile (all shapes are rectangles with 5 attributes) from QGIS, it was still trying to save for over 2 to 3 hours before I killed it. ...
2
votes
1answer
760 views

Problem with Saga in Qgis 2.14.6

I am trying to run saga tool however I always received errors. I am using Ubuntu Xenial Xerus (16.04), Qgis 2.14.6 and Saga 2.2.7. Log (OGR) error: 2016-09-07T15:22:28 1 Data source is invalid () ...
2
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0answers
171 views

QGIS SAGA Raster Calculator returns incorrect results

The SAGA Raster Calculator within QGIS produces wrong results probably due to interpolation but works corretly withion SAGA itself. The problem has been discussed here before but sofar I have not ...
3
votes
2answers
727 views

“Object based Image Segmentation” and some options are absent in SAGA

Although I have the latest version of SAGA, "Object based Image Segmentation" and some options do not appear when I click on "Geoprocessing>Imagery> Segmentation>? " Why are they absent?
2
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0answers
51 views

Warning from SAGA when doing Topographic Corrections?

I am trying to use SAGA for topographic corrections for the first time, however I am getting a warning that says: data not in the same grid Can any one suggest ways of formatting the data (DEM and ...
3
votes
2answers
129 views

Preserving Projection on SAGA-produced Rasters

I perform a fair amount of hydrological processing in QGIS and rely on SAGA's Topographical Wetness Index and slope-derived functions. In order to use them, SAGA demands that input rasters are warped ...
4
votes
2answers
978 views

QGIS: SAGA-GIS module “Add raster value to point” Error: unknown option 'INTERPOL'

I encountered an error while using the "Add raster value to point" SAGA-GIS module in QGIS (2.16) to retrieve altitude values from a raster DEM previously interpolated from TIN points (as vector ...
3
votes
2answers
2k views

Problems with Saga integration in QGIS 2.14.4 LTR

I've installed QGIS 2.14.4 LTR (32 bit) on my WIN7 64bit system. But I believe something is wrong with the "Processing" plugin as many of the features were missing from what I've used earlier. My QGIS ...
1
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0answers
24 views

Tiger WOIS Could not open workflow

Recently I have been trying to use the TIGER WOIS package which looks really useful. I'm trying to use the Flood mapping tool with Sentinel-I data, but I encountered a problem right away. In the ...
-1
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1answer
221 views

SAGA-GIS (2.3.1) fatal error during compilation (Ubuntu 16.04) hdf5.h not found in /usr/include/vigra/ subdir

OS : Ubuntu 16.04 Compilation using : ./configure && make I encountered a fatal error while compiling SAGA-GIS 2.3.1 : Making all in imagery_vigra make[5]: Entering directory '/home/...
2
votes
0answers
523 views

SAGA GIS work with python API error

I want to work with python API and SAGA GIS. I am very new with this work. The first step I find one module for example Slope, Aspect, Curvature and I take with right click one python script. python ...
2
votes
1answer
167 views

SAGA Raster Calculator in QGIS Graphical Modeller not subtracting [closed]

I am using QGIS 2.8.1 to build a model. All is working fine until the raster calculator input. I understand that the raster calculator in QGIS Modeller is a SAGA tool. With this, I have tried both the ...
1
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1answer
590 views

QGIS- extract raster information into a point return nulls

I have a 1) raster layer and a 2) point layer. I want to extract the pixel value to each point, but it is not working when using this tools (QGIS): plug-in "Point sampling tool" (the new shapefile ...