b'Data trends Data trendshence the need for code\x08 The variableAssigning a value to each point is data OriginMod moves the bottom left handdependent and philosophical so I have starting origin for each iteration\x08 not included a method in the script\x08 The process is quite easy in modern A test was run using 3 overlappingGIS packages with the very easy to use surveys (Figure 1) where the largestSpatial Join (ArcGIS and QGIS) set to spacing is 250 m\x08 An initial spacing ofassign the nearest value within a search 500 m was chosen and run for threeradius\x08 However, searching only that far iterations to produce regular pointsoften leaves points null\x08 A wider search (Figure 2)\x08Tim Keeping Associate Editor for geophysical data management and analysis technical-standards@aseg.org.auPoint gridding revisitedI have prepared some GIS Python code to follow up on my last column in Preview and to help the time consuming job of regularizing irregular points (Table 1)\x08 The code uses a layer or shape file to iteratively create multiple sets of points with half the spacing of the previous iteration\x08 The code is for ESRI ArcGIS but I will try to point to similar QGIS functions\x08Figure 1.Gravity survey points of three surveys over the Andamooka area demonstrating the irregular The code below is just a copy of thepoints common to exploring. Surveys are 1980R7, 2006A8 and 2010A stretched by Bouguer Anomaly values. Fishnet function help file code with a fewSurveys were downloaded from the SARIG website (https://map.sarig.sa.gov.au/).extra variables and a while loop\x08 If you want to add to your ArcGIS toolbox, the parameters are-Layerfile name (a layer or shapefiletype)-Folderthe output folder for all filesproduced (Folder type)-Initial Spacingthe largest initialspacing between points (type Any Value)- terationshow many generations of Ipoint sets to make (type Any Value)The user sets the initial spacing between points and how many iterations of point sets with decreasing spacing to write to the output folder\x08 The Create Fishnet function is the easiest way to make a set of points the same area as the target area\x08 I have not identified the equivalent in QGIS yet\x08 I found Create Fishnet needed a bit of help ensuring allFigure 2.Regular grids created using the attached code. Three sets of points were iteratively created with data sets have points that overlap, andhalf the point spacing of the last500 m (square), 250 m (circle) and 125 m (dots).FEBRUARY 2021 PREVIEW 30'