Field calculators (available in QGIS, ArcGIS Desktop, etc) can recalculate the values of a single field on all, or selected, records within a table using an expression.

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201 views

How to create sequential field based on sorted data? (or extract pop-up data?)

I downloaded a kmz field and converted it to a GDB fc on arcmap. However, the field I need to label the layer by is stored in the pop-up html field... It looks like this: <html ...
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157 views

Calculating a Unique ID on a Subgroup of Polygons

I would like to assign a unique ID to polygons in a dataset. The catch to my issue is that I would like polygons that fall within a polygon to have the same unique ID. My example is related to ...
3
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1answer
132 views

How to calculate the intersected area from a layer with overlapping buffers in qgis

I need to calculate the area of landusetypes in 50m around various dots (all in one shapfile). My problem is, the buffers around the dots are overlapping each over in some places. I tried to ...
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2answers
38 views

Use Python in Field Calculator to increment up value

Please see screenshot for field calculator Python logic. I have no idea what I'm doing that's any different from this GISSE answer. The error I receive is ERROR 000989: Python Syntax Error (invalid ...
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1answer
74 views

Cannot convert string to int using ArcPy Calculate Field

When I load a csv file to join with ArcPy, it converts all string fields that are numeric to integers. Therefore, I have to add another field within the feature class that I'm using for joining that ...
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95 views

basic problem using division in field calculator

This is a very basic question, but I can't figure out what's going on. I've got election results I'd like to simply display as percentages rather than vote totals, which should be as simple as ...
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35 views

new layer from calculations with fields of other layers in QGIS

I've two layers, both with the same fields: A, V, where A is the shape's area and V a value given by me. I want a new layer with shape created by the intersection of the other layers' shapes and a ...
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21 views

Create field on open ArcGIS map - not saved

I am using ArcGIS desktop with an SDE feature layer with enterprise data that I do not have rights to edit. The data changes weekly but I need a field that is sum of 2 current fields without creating ...
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30 views

if/then with VBScript in ArcGIS Field Calculator giving Error 000539: SyntaxError: invalid syntax?

What is wrong with this VBscript in the field calculator? ColumnC= if [ColumnB] > 0 then [ColumnC] = [ColumnA] / [ColumnB] endif Each time I receive this syntax error message: Error ...
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30 views

ArcGIS Calculate Fields gives Warning 000405 No records within table?

Situation: I have feature layer sitting outside processing extent in Environment settings. If I open layer's table and use field calculator - Calculate Geometry on some numeric field: it works ...
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1k views

calculating a field in which null values may be present

I would like to calculate a field (short integer) using other fields (short integer) present in the table. In some cases these fields may have null values for one or more of the fields. For example, ...
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55 views

Line length for line files

Using QGIS, Brighton 2.6. Trying to calculate line-lengths for linear features (roads, trails, fenceline) and used this post (How to find line length in QGIS while editing?) and the links associated ...
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91 views

ArcGIS Python syntax error using nested if else

I am trying to use the field calculator in ArcMap 10.2 to fill an empty field based on the contents of two exiting fields usint this python script in the Pre-Logic Script Code. def ...
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220 views

Calculate Field in ModelBuilder gives General error executing calculator. ERROR 999999: Error executing function. Expected end of statement?

I am attempting to do zonal statistics for multiple images and I need to add an extra field that will have the name of each raster file in each row to the finally appended file. I have added a field ...
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1answer
315 views

Join and Calculate vb.net

Im trying to join an excel table to a shapefile and then calculating those fields using vb.net. The code I have written has no errors, but won't work when I try it in ArcGIS 10.1 and I'm out of ideas. ...
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2answers
127 views

Using Python in the field calculator - if/else over multiple fields

I'm trying to work out how to populate a field depending on the lowest score across 6 other fields. I've read several other questions relating to if/else statements but I'm only just starting to learn ...
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2answers
2k views

Recoding values based on contents using ArcGIS Field Calculator or Python?

Is there a convenient (or even effective) method for recoding field values using the field calculator or standalone python script? In this case, I am given several unique strings to identify a type ...
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2answers
63 views

Setting field equal to raster Name ID for batch process in ArcPy

I am wanting to set an existing field called RasterID to the name of the raster for which the attribute table belongs to, but for a batch of rasters. Is there a way to do this with my current code ...
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60 views

Using ArcGIS field calculator?

This field calculate returns an error, whats wrong with it? def Reclass(A): elif ( A>= 0.208113 and A <= 0.261517): return "Low" elif (A > 0.261517 and A < 0.301951): return ...
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96 views

How to pad field with blank spaces using calculate field tool of ArcMap?

I am trying to pad the right side of a field with blank spaces so that when I label the field, it labels further over to the left. The only way that I can seem to make this work so far is by adding a ...
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1answer
47 views

Populating a field in an attribute table with a consecutive number sequence? [duplicate]

I know that this is probably a very basic question but I cant seem to find an answer through Google searches. I would like to create a field in an attribute table (in ArcMap 10.2) for a Number Label ...
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1answer
39 views

Calculate values in one field based on values in another field

I have one field with Zoning Codes (i.e.: RS) and I want to update another field with the string "Residential Single Family". The new field is currently NULL, I would like to add the full text string ...
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26 views

Joined tables and now field calulator is greyed out

In ArcMap (10.2), I accidentally calculated the wrong field outside of an edit session, so there was no way to reverse my action. I restored a previous version (shadow copy) and joined the tables ...
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209 views

How to find if polygon has a hole using field calculator in ArcGIS

Some 3rd party software cannot handle polygons with holes (donut polygons). To find them I always use ArcView 3 field calculator, because: however when I try to do this in ArcGIS, I get this: So ...
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24 views

Sum a field, and take that sum and use it to populate an existing field in the same table

I am trying to break down land uses in a watershed by making a tool in ModelBuilder. Right now I am clipping a land use layer by a watershed polygon, dissolving land use layer by land use code, ...
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688 views

How to Populate new field using expression containing MAX value from another field in ArcGIS attribute table using field calculator?

I've got one field X with 10 numerical attributes (float/double). I've created a new field Y (also float/double) which I need to populate with the percentage of each record/attribute (in each of the ...
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378 views

Calculating Stream Length-gradient Index (Hack Index) with the field calculator

I'm trying to calculate the Stream Length-Gradient Index of a stream (example data below). Just started to get into python, but am struggling with a solution to this problem. I have 42 streams to run ...
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196 views

Extract numbers from string field

I am trying to calculate field test2 with only the numeric values from a string field test. The entire script is like: def makestr(test) list=[] for s in test: if s.isdigit(): ...
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1k views

ArcGis Python Script, Calculate Field

Sorry for my English. I am trying to write a Python Script for ArcGis 10.2. #import system modules import arcpy import math from arcpy import env #Set environment options ...
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2answers
1k views

Forcing decimal numbers to use comma in ArcGIS Field Calculator?

Can I add the comma "," to force the decimals to remove from the attribute and replace with the number? For example, I have an Acres field column that says 506320.0750 and I want to replace the ...
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1answer
21 views

How to fill column with several conditions using QGIS field calculator?

I know the synthax in order to fill one field with only one condition (field calculator): case When "attribut" = 'value' then value End But how to do populate automatically one field with ...
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1k views

Getting ValueError: max() arg is an empty sequence on a Python Script in the Field Calculator in ArcMap

I have a script that populates a FacilityID Field on a Attribute table in the Field Calculator but when I run the script below I am getting a error. EDIT: Python Script: def autoInc(): import ...
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122 views

Calculating file name with field calculator

Is it possible to calculate the file name in an attribute table? My shape file has a name like "cities.shp". In this shape file I want to have a attribute "cities").
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31 views

Multiply whole column with the field calculator in QGIS

I have a layer with the field size. I did some mistake with the value and now I need the values multiplied by 16. But instead of going through 500 lines and recalculating them I would like QGIS to do ...
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1answer
21 views

How to update the value of a field dependant upon the the fields ID in QGIS Field Calculator

I am looking to create links to website pages and to automate the procedure a bit more I would like to have a standard link followed by the ID of each field. For example, I would like the standard ...
2
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3answers
72 views

Prefixing multiple values within QGIS using the Field Calculator?

I have a column in my my attribute table that contains a series of individually numbered locations. I wish to prefix all of these numbers with a letter, this letter will be the same for each of the ...
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31 views

Changing field values using arcpy

Say I want to make my field buff_dist longer than by 400ft, I want to write a code that will go through the table and change the field value by adding 400ft to it's value. How would I write that? I ...
2
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1answer
79 views

Converting values in datetime field to strings in text field using Python parser of ArcGIS for Desktop?

In the attribute table of my file geodatabase feature class I have a populated field called DateField of type date, and a text field called TextField. I have not yet hit on a way to convert the ...
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61 views

Accumulating values of date field using Python parser of ArcGIS Field Calculator?

I would like to modify the following accumulative/sequential python code sample in field calculator in a Date Time field. I think this is the correct code to use but let me know if not. The Date Time ...
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1answer
271 views

How to classify time periods in a new field, using Python?

I have a datetime field (Horario) in my feature class, showing only the time. Although the date doesn't appear, it seem to be stored automatically as 30 Dec 1899, I'm not sure why. I want to use ...
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124 views

Are Date columns in feature classes stored as python datetime objects?

I have a Date column called readings_measurement_tstamp stored in my feature class. I would like to add a String column to this feature class and Field Calculate it to be be just the %H:%M:%S ...
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1answer
25 views

Adding formula in field calculator when new attribute is text type?

I added a new text attribute to my table. I would like it to print the values "y" or 'n", for when an attribute in the table is other a specific cut off it will code Y, and then that attribute is ...
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3answers
3k views

Basic Field Calculator help

I have no experience with Field Calculator in ArcGIS 10. I have a very simple calculation I would like to perform that I could do easily via pure SQL but just can't seem to get my head around it in ...
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1answer
61 views

Calculating Percentiles in ArcMap?

I have a large polygon dataset (26,000) records with numerous attributes columns. I wish to calculate the percentile rank of each attribute. Say I have population_density in an attribute, is there a ...
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1answer
174 views

How to calculate unique IDs starting from highest current ID

I have been using a python script in field calculator in ArcGIS 10.2 to add unique IDs automatically, however there are two things I would like to improve this process: Each ID also has letters at ...
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70 views

Concatenate Multiple String Fields and Convert to Date field using ArcGIS Field Calculator?

I'm Working in Model builder using the calculate value tool. I have three columns - SignatureDay, SignatureMonth, SignatureYear - All three are string data types and all consist of just numbers for ...
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748 views

ArcGIS Field Calculator Python numbering rows of fishnet

I have a grid of 100*100 cells. I want to add to each cell a number representing the row it is in (like in excel). I added a field and want try to solve that with field calculator: The code is ...
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431 views

Using Python in Field Calculator to compare two fields

I'm trying to use field calculator to compare two fields in a table of tax parcel data, Land Value (LAND_VAL) and Improvement Value (IMPRVT_VAL). My goal is to determine (1) Parcels with land value ...
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103 views

Using Python For a Field Calc

In AcrMap 10.2 I'm trying to add a field and run this script in Field Calc: !shape.isMultipart! to see if I have any multipart lines. I keep getting geoprocessing failures. I am clicking the ...
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66 views

How to perform If Statement in Field Calculator of ArcGIS for Desktop? (Python or VB)

I've one field "MAXSPEED". I want a Field Calculation that will calculate an additional field ("noise"): If MAXSPEED > 40 then the term: (73.5 + Log ( 25 ) * ( [MAXSPEED] / 50)) should be used to ...