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Questions tagged [loop]

A sequence of instructions that repeats either a specified number of times or until a particular condition is met.

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7 views

Iterating through fields of shapefile for batch interpolation? [on hold]

Here's my difficulty. I know there's no way to iterate through the fields of a shapefile using the ModelBuilder in Arcmap. But, I know there must be a way to do it using arcpy. But, my skills with ...
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0answers
22 views

Creating loop in raster algebra which compares each cell to values of other rasters in time series?

I have a list of rasters representing NDVI values (and plan to do similar thing with some other index values as well) and in that raster I also set all values representing clouds to NoData. Now, for ...
2
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1answer
25 views

Nested loop and terrain analysis R

I have a raster stack with 11 layers that I am running through a triply nested lapply(). I expect 44 layers to be returned, but I'm only seeing 4! Reproducible example: # Load packages library(...
2
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1answer
30 views

ReduceRegion Loop GEE [closed]

I'm trying to loop a ReduceRegion function in Google Earth Engine to obtain a month mean NDVI over a polygon. But I've not been successful yet. I did for one month. At the end, I should have a list ...
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0answers
28 views

Make a script run indefinitly

I have created a script which reads a JSON file and based on the attributes creates a grid and assigns values to the grid. This JSON file may change. I wanted to create an infinite loop to run the ...
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1answer
14 views

How do I implement a JSON file with coordinates into a var with featurecollection? (TURF)

I am trying to use the nearest function in TURF, so what I have is a JSON file with information about parkades: { "type" : "FeatureCollection", "name" : "ubcv_parking_www", "features" : [ { ...
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1answer
40 views

Buffer loop with Python QGIS

I want to iterate a buffer from a list of distances I have, but I can´t find the way to do it. I´m a beginner on Python. import processing x=[100, 200, 300, 400, 500] processing.run("native:buffer",\ ...
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2answers
44 views

Loop through a range of rasters and use tool output as input for the next tool run

I'm using the particle track tool and limiting it to a specific trackingtime. For each tool run, I want the rasters input (magnitude and direction) to change to the next rasters in the lists, and the ...
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1answer
42 views

Including conditional operation depending on number of images?

I want to do certain operations depending on the number of images in a filtered collection. I am working within a loop, so I need the condition to jump to the next step in the loop given a condition. ...
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1answer
56 views

Looping a raster stack with a step, R

I have a large raster stack of about 500 rasterlayers. What I want to do is to extract specific layers and store them in a different strack. The layers for which I am interested in, have a step of 8 ...
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1answer
29 views

Loop through two raster datasets by order and perform a function

I have two raster datasets that I need to loop through by order and select the first raster from the first dataset with the first raster from the second dataset to perform a function. I keep getting ...
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1answer
35 views

Export raster over a loop in Google Earth Engine

I would like to export raster in a foreach loop with : var landCover = ee.Image('MODIS/006/MCD12Q1/2016_01_01').select('LC_Prop1'); var countries = ee.FeatureCollection('USDOS/LSIB_SIMPLE/2017'); ...
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18 views

Extract values from multiple rasters based on lookup of raster file name

I have 11 raster files (waveheightfiles), and need to extract one value from a different set of coordinates (station) for each raster. I have a list of 11 coordinates (df2) and have used part of the ...
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1answer
23 views

Looping a function over a sequence of parameters with iterate()

I built a function landcov(area, date) to calculate the share of land types 0 to 3 in year "date" from MODIS12Q1 within the polygons of the "area" parameter. I want to use iterate() in a loop-like ...
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1answer
74 views

Looping Eliminate tool in Python?

I am very new at Python,I'm not sure if this is even the appropriate way to do what I want to do, but basically, I'm looking to eliminate all of the small polygons in a feature class that was created ...
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2answers
85 views

Looping through a table to allocate kids to nearest school

The general problem is to allocate town's kids to their nearest school and get the distance and the geometry. Tools in use is Postgresql 10.6, PostGIS 2.4.3 and PGRouting 2.5.2 There are three ...
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1answer
49 views

Using for loop in least cost path analysis using ArcPy?

I am doing a least cost path analysis. I need to create a for loop that will run 3 times and select the correct weight from each of the two lists (slope and land). Slope = [10, 20, 30] Land = [30, 20,...
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1answer
167 views

turf.js point never found inside or within GeoJSON features loop

I have a GeoJSON http://radikal.com.mx/distrito.json and all I am trying to do is find if a turf point that has a longitude and latitude is inside or within that GeoJSON. No matter what point I use I ...
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1answer
90 views

Calculate difference of subsequent images in a collection

how do I call a Specific Image inside a Collection, to loop over it? this is for calculating the difference of images for each set of two subsequent images in a collection dImage= Image(t=i+1)-Image(...
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0answers
13 views

ogr2ogr loop through feature classes in FGDB except one feature class

I have multiple fgdb and I wanted to merge this to one FGDB and this is the command I used so far find . -path "*/*1*/*.gdb" -o -path "*/*2*/*.gdb" -o -path "*/*3*/*.gdb" \ -o -path "*/*4*/*.gdb" -o -...
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2answers
41 views

Arcpy UpdateCursor not Updating, but no Error Reported

Below is the code I'm using in an SDE GDB, on ArcMap 10.4.1: import arcpy # Variables inputAsbuilt = arcpy.GetParameterAsText(0) transmedia = inputAsbuilt + "\\Transmedia" structure = inputAsbuilt + ...
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1answer
403 views

Iterate through list of field names and calculate fields with PyQGIS?

I am using QGIS 3.2.1 Bonn 64 bit on Windows 10. I would like to loop through a list of field names and perform calculations on each field. Only the first loop in the iteration performs any ...
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1answer
71 views

calculation with raster and numeric values in Loop with R

I want to do some calculations with a list of rasters of lakes. Therefore I wrote a loop, which has so far worked fine when I only used rasters. Now I have calculations with rasters and numeric ...
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1answer
137 views

Creating a Loop in R for averaging Raster values to create time series

I have calculated several different indices for lakes stored as GEOTiff. I now want to write a loop with R to average the values for each lake, so only one value is left for each lake. And then create ...
1
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1answer
38 views

Reducing monthly averaged MODIS data over several ROIs

I want to create monthly averages for the MODIS Land Surface Temperature (LST) product for several ROIs. I am able to create an image collection containing the monthly averaged MODIS data, but I have ...
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2answers
48 views

R: Writing individual variables from a RasterStack in loop

I have a RasterStack with 3 layers each one of them containing 19 variables. Using writeRaster I need to save specific variables into my directory while naming the saved files with the actual variable ...
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1answer
28 views

gdalwarp for clipping images using multiple polygon in a bash shell for loop

C:\OSGeo4W64\bin\gdalwarp.exe -dstnodata 0 -q -cutline D:\hillsborough_Images_work\split_Polygon\120-140k\Hillborough_FINAL_140000_region_IGD_120570003d29ed0dc.shp -crop_to_cutline -dstalpha -tr 0....
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0answers
56 views

Saving rasters in Arcpy loop

I'm trying to do Map Algebra on a bunch of rasters by iterating through a for loop and saving them in an empty geodatabase. However, they aren't saving properly. Only the last raster is created and it ...
2
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0answers
56 views

Map Algebra loop only creating one raster

I'm trying to transform a bunch of rasters in arcpy according to specific functions to create suitability rasters. This portion of the code is supposed to find all the rasters with interpolated ...
1
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2answers
173 views

Batch Calculating Indices

I have 111 Landsat8 scenes which I want to calculate several indices for. The algebra to calculate them is most of the time Index= (b1-b2)/(b1+b2). I have the single bands (bands 1-11 respectively) ...
3
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1answer
94 views

Can't do anything else in QGIS during While-Loop

I've written a Python QGIS plugin that reads data from an AIS receiver via the Serial package. It will be similar in function to the GPS Information panel in that it will show your position on the map ...
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1answer
136 views

Running MaxEnt modelling in “dismo” using “loop” and storing the results in seperate objects and folders [closed]

I am doing a MaxEnt modelling using "dismo". I am using a loop to give multiple runs. I wanted to save results from individual runs in separate objects and at the same time the results from individual ...
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1answer
38 views

Writing Nested Loops Using SelectLayerByAttribute_management Iteratively over Multiple Fields?

I need to select all rows matching specific values across 3 columns and then iteratively change one value at a time and continue making selections. The reason is to capture certain summary statistics ...
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1answer
231 views

Applying a Loop for my code in R

I am trying to apply a code (in R) for all images that I have in a folder. The code works for 1 image, but when I try to make a loop out of it, it gives me error. library(raster) library(rgdal) ET<...
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2answers
56 views

Script Python on ArcGIS works but do nothing [closed]

I am trying to automate a loop for the Alter Field tool. As the code snippet that comes with the help fits my problem, I used it by changing the workspace path. I also tried passing the path with ...
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1answer
66 views

Combining two models, one having an iterator

I have two different ModelBuilder models: Create a new field and split a layer Merge all layers in one folder I want to append both models in one but it does not work. The Model have a loop and I ...
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2answers
179 views

how to loop ndvi using R in sentinel-2

I have a two different stacks: one for band 4 (RED) and other with band 8 (NIR). I'm trying to loop the calculation of NDVI in an area of interest using R. Well, this is the loop that I'm trying to ...
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1answer
40 views

Loop For to export polygons from a Feature Class

I need to export 150 polygons from a feature Class. I have a python snippet code to export the polygons one by one. I think a for loop code can do it fast, but I don't know how to write the code into ...
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1answer
56 views

ogr2ogr apply sqlite dialect to multiple feature classes within a fgdb

I have a quite many feature classes in a filegdb and they all have same data schema (same field names and etc). I wanted to apply a single sqlite query and I am having hard time to make a loop ...
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1answer
77 views

Reproject all layers in a spatialite file using ogr2ogr

I would like to reproject all layers in a spatialite file from one srs to another srs. Is there a way I can archieve this without parsing the layers names to a txt-file? I know I can write all ...
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2answers
111 views

Selecting layers of a raster stack using a sliding windows as a step in R in for loop

I would like to create a loop that every time selects the first ten layers of a raster stack, calculates their mean and saves it to a layer of a new raster stack. Also, I would like to have a step ...
2
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2answers
165 views

GRASS r.in.lidar (las to raster) inside Python loop?

I have a loop in Python to list out LAS files in a folder, and run two commands in Grass GIS on these files to write them out as rasters. The loop runs but at the end I get an arg must be string not ...
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1answer
34 views

Looping Sub-folders to merge shapefiles export by sub-folder name to file geodatabase [closed]

trying to loop through folders, merge shapes in folders, naming my folder name, export to feature class in file geodatabase. **merge loop** import arcpy from arcpy import env import os **Workspace*...
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1answer
119 views

Batch clipping with multiple shapefiles in ArcPy?

I am trying to create an ArcPy script to clip multiple shapefiles (2,000) to the census tracts in LA County. I have successfully run the code on a single shapefile and am trying to convert the code ...
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1answer
517 views

ModelBuilder: Error 999999 “Failed to copy raster dataset”

I want to run the "Project Raster" tool in the ModelBuilder of ArcMap but I get the "ERROR 999999: Error executing function. Failed to copy raster dataset." and I have no reason why. Input is a ...
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1answer
54 views

ArcGIS ModelBuilder looping wrong tools?

I've created a toolchain in ArcGIS ModelBuilder (see in the picture) But after Creating the "Flow Direction" and the "Iterate field Values" it starts again with the "DEM reconditioning", it's an ...
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0answers
40 views

Creating separate shapefiles for each attribute record using loop in ArcPy? [closed]

Line 24 fixed, final code now updated. Line 22 since fixed , now I get the error Traceback (most recent call last): File "C:\Users\shehn\Documents\ArcGIS\PyScripts\lab6X.py", line 24, in arcpy....
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1answer
156 views

Looping for NDVI in different file paths using R? [closed]

I have different bands separated in different file directory. I used Raster Calculator to calculate NDVI using "NIR1.tif"-"RED1.tif"/"NIR1.tif"+"RED1.tif" as formula. The link below describes a loop ...
4
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3answers
566 views

Looping if condition in ArcPy?

I want to use "Calculate field" based on the string in another field. I would like to loop if condition but something is wrong and I am little bit confused. I am super new in Python. Here is my ...
1
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1answer
86 views

Saving output in ArcPy?

The loop runs once, then i get this error message. Runtime error Traceback (most recent call last): File "<string>", line 17, in <module> File "c:\program files (x86)\arcgis\...