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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40 views

Calculate field with a value in a list based on field

I didn't want to write an if statement for every field. I wanted to know if there was another way to field calculate each field with the values related to it in this example table. Fields (X,Y,...
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2answers
27 views

Is there any way to force a loop to go until the last list object in R?

I am running a loop in R to rasterize a list of data frames and for comparison purposes I have to keep the same list length in the output. I am facing some problems with NULL objects on the list. I ...
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1answer
57 views

Loop checking if attribute field exists in PyQGIS

I'm building my first script and I need help to create a loop instead of my repetitiv functions. The aim is to check if every field already exists, and to build it only if it doesn't. This script ...
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1answer
23 views

ArcPy: Delete field loop with if exception

Am new to ArcPy , am trying to join the same features from different geodatabase but I don't need all of attributes, so want to make a loop to find each feature class and delete the fields I don't ...
3
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1answer
61 views

How can I process vector difference between 1 group layer and 1 polygon layer?

I have one layer group called 'left_buffer', containing 40 buffered polygon layers (name: 1,2,3,...,39,40). I want to use difference vector tool between 'left_buffer' and 'bldg' layer, but I'm getting ...
3
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1answer
42 views

Export looped layers at once using PyQGIS?

I am trying to use one-side buffer on road centerline (layer name: small_road) by 1~40m. I've succeeded in creating one buffer (2m) file at a time using 'SEGMENTS':2,'JOIN_STYLE':0,'MITER_LIMIT':2,'...
1
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1answer
45 views

Count the number of pixels according to their value using for loop

I have script that does the enxt procedures: create imagecollection from Landsat7 clip the images according to specific geometry and calculte NDVI for each one filter the rasters according to the ...
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0answers
13 views

Copying Features from multiple sources

I'm new to Python and trying to automate copying specified features from a bunch of nested geodatabases into a new geodatabase- script seems to work ok, except for the copying features part (the 2 ...
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1answer
52 views

Map algebra with loop and SetNull not working

I'm trying to run a loop through a number of rasters while using SetNull but keep receiving an error message. I have worked on these rasters individually using SetNull and it it works, but would need ...
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1answer
32 views

Use GDAL to resample and stack multidate image spectral bands

I have a Sentinel 2 multidate image data set and I'm trying to resample all of them at 10m and then stack them to apply a cloud mask, in Python language. Being new to programming, I have a hard time ...
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1answer
54 views

Iterate through raster in R and apply conditional statements

I have a raster data set in R with numeric values ranging from 0 to 61.5, including some random NAs throughout. I would provide a reproducible data set, but I don't know how to create a raster with ...
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2answers
46 views

Select_analysis Looping gives ERROR 000732

The script I use for select_analysis is no longer working. I believe part of the problem is the source data I use (and I'm not the administrator of) has changed the field properties of the attribute I ...
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1answer
28 views

Iterating through geodatabase and assigning field value based on spatial location using ArcPy - Part 2

This currently loops through my dataset and calculates the installation ID field from my dataset with the installation code from my Bragg Area feature that are within the polygon of each row. It works ...
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0answers
19 views

Iterator (Iterate Feature Selection) running loop in undesired path using ArcMap ModelBuilder?

I am building a model using Iterate Feature Selection. I want to run the Iterator -> select by location -> Calculate field, and after finishing this loop (#3 in the image below), I will continue to ...
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0answers
33 views

Loop in ModelBuilder in a specific situation

I would like to make a loop in the next model base on a expression, this expression received a code with consecutive numbers in a reference layer call "sector", to summarize, for each "code" do a "...
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1answer
41 views

Loop through geodatabases and list feature classes [closed]

Trying to find a way to use Python or SQL to loop through geodatabases and print the feature classes. I'm not sure what the difference between while and for loops are; I'm brand new to scripting. A ...
1
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1answer
52 views

Looping through two raster folders to perform raster calculation?

I have two geodatabases with rasters containing information about "treecover" and "loss". The file names are slightly different but can be matched based on the last 8 characters (the coordinates of ...
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1answer
109 views

Loop with predict raster function in R [closed]

My data is a dataframe of ALTITUDE in the first column, and monthly temperatures (let's say for a year) in the other columns. I used the following code to create a linear model for each monthly ...
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2answers
41 views

Use ArcPy for finding value throughout all fields and export to new layer

I need to find a way to find a specific value in the attribute table and then export all rows with said value to a new feature class. Below is the code that I have managed to come up with (using ...
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0answers
134 views

Extract time series from ImageCollection for multiple points - Google Earth Engine

I have the Sentinel 2 (COPERNICUS/S2) ImageCollection and a FeatureCollection of points. I want to extract a time series for each of the points from the band information in the ImageCollection. So ...
0
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1answer
27 views

Write a text file per image with same name in R

In R I would like to create a text file for each picture I have in a folder and with the same name. By example: Picture 1.png - Picture 1.txt Picture 2.png - Picture 2.txt But the text file name I ...
1
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1answer
90 views

Make a loop in Google Earth Engine for reduce NDVI from year a months?

I have this code, it generate N ImageCollection and for each image a chart from NDVI in function a the months This is the place of study: var areaEst = ee.FeatureCollection("users/aleszczuk/...
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1answer
43 views

Didn't show all the column while export the CSV file while using Google Earth Engine

I'm trying to calculate the water areas and the statistics of each band for each water areas to see if there are seasonal changes. The exported .csv file only have the columns ("GNIS_ID","AreaSqKm","...
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0answers
253 views

Data organization in Google Earth Engine image collection?

I defined an image collection contains all landsat SR images(LT5,LE7 and LC8) only including some specific bands each. Finally 685 images in path 120 and row 32, each contains 10 bands were selected. ...
0
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1answer
60 views

Multiple selections with a python loop

I am very new to Python and have no idea about how to write a python loop to do selections for ArcGIS. I already finished writing selection codes with different conditions. Is there anyone helping me ...
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0answers
33 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
64 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
225 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
33 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 ...
0
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1answer
218 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" : [ { ...
1
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1answer
96 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
53 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
201 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. ...
1
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1answer
562 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 ...
0
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1answer
44 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 ...
0
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1answer
167 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'); ...
1
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1answer
46 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 ...
1
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1answer
83 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 ...
1
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2answers
105 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 ...
0
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1answer
79 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,...
0
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1answer
486 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 ...
1
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1answer
385 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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2answers
88 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 + ...
4
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1answer
695 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 ...
1
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1answer
186 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 ...
1
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1answer
188 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
66 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
174 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 ...
0
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1answer
58 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
107 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 ...