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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ExecutING SQL script in ArcGIS field calculator?

I am trying to transfer over row data from a table to columns in a shapefile table. There is a common "SA" variable between the two (i.e. the study area number) but there is more than one land use ...
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Translate Excel formula to be used in field calculator

I have a series of equations to create corner points to make rotated polygons based on angles in the attribute table, but I have created it in excel and can't figure out the syntax to get it to work ...
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740 views

Capitalizing The First Letter Of Each Word In Attribute Field

Does anyone know of a way to capitalize the first letter of each word in a field in an attribute table? I am doing this in QGIS. I know of field calculations to change all the words to Lower or ...
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Calculating Quarter (Q1, Q2, etc) using Date field in ArcMap Field Calculator?

I am using ArcMap 10.0 and making a map where I symbolize on annual quarter (i.e. Q1 2013, Q2 2013, and so on by quarter through 2015). If a date field contains this: 01/15/2013, and I wanted to ...
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How to add a sequence to the attribute table?

Is there a way to use the field calculator in QGIS to create a range of values in a count sequence with a specified input range? For example, if I wanted to have the values 1 to 5 repeated within my ...
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Filling in patterns into attribute table column of ArcGIS?

Attribute tables in ArcGIS are not nearly as easily editable in comparison to something like Excel. For example, you have sorted the table based on some column value, and now want to fill in the ...
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How to create a label formatted like “ 1,000' ” from a numeric field?

This question builds on a previous question I came across at gis.stackexchange: How to easily edit attribute data using Regular Expressions? Perhaps someone can point me in the right direction? I ...
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Recording frequency of names in the attribute table?

I have a question with ArcGIS 9.2. In an attribute table the column [name] includes the name of every place in this layer. Next to that (in columns [numbers]) there should be recorded how often a ...
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ArcGIS 10 Python split string

I am trying to use Python to split a string field into three new fields at the separator " - ". The field is in the format "a - b - c". So I initially had this in the field calculator for newFieldA: ...
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How to calculate with time values in QGIS?

I have two string fields in a vector layer, "From" and "To", with values in the format of 10:16:30 and 10:18:00 e.g. I would like to calculate the difference in minutes as a decimal value, in this ...
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How do I fill in serial letters (AA, AB,AC…,BA,BB,BC…ZZ) to a shape?

(I am using ArcGIS software, ArcMap...) MY PROBLEM I have a shape file containing points. The shape file contains 3 columns named FID, Shape* and Label. In the column I want to fill in AA, AB, ...
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How to do a simple find and replace in QGIS field calculator?

I'm trying to replace selected string values in an attribute table, eg. "Text1" for "Text2" (QGIS 1.8.0), patriculary for those rows with NULL values. I have been trying to use the replace expression ...
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How do I extract partial data from one field to another?

Answer Below I am attempting to extract a date stamp that is contained in one field and insert it into another field. The issue is that the date (in bold below) is not in the same location in each ...
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Field calculator script to work out first 5 dominant area fields?

I have 5 fields of different landcover types with areas of each and found below: > PRC_Water| PRC_Bare| PRC_Urban| PRC_LVeg| PRC_LVeg| > 5 20 40 20 15 I have ...
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734 views

Why does ArcGIS Field Calculator expression unexpectedly return a binary value (0 or 1)?

I am running simple field calculator expressions and experiencing some of the silliest results I have ever seen. I am working on census data (living as a shape file) and trying to perform a simple ...
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Using Range in Python expression of ArcGIS Field Calculator?

what is the python expression for defining a range of numbers? I have tried numerous combinations but cannot get a simple range of angles (100 -200) to compute correctly. Screen shot :
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Using field calculator to delete specific contours

I have 3 contour shapefiles with 25m, 50m and 100m equidistance. Now I want to delete in the 25m-shp-file every **50m and **00m contour and in the 50m-shp-file every **00 contour. How can I show them ...
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How to replace arcpy.CalculateField_management with an update cursor?

I'd like to replace this expression arcpy.CalculateField_management(bufferFile, "Shape_Area", "float('!shape.area@squaremeters!')", "PYTHON") with an arcpy.da.updatecursor. The reason for this is ...
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Calculating the average / MEAN of an attribute field in a QGIS model

I need to know how to calculate the average / mean of an attribute field in my point shape file. Is this possible to do with the field calculator? I just found the options min or max but not mean. The ...
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513 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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Calculation based on features in shapefile

I hope I get the terminilogy right! Correct me if I mess something up. I need to perform some calculations for a scoring system for different habitat types. The Problem is that I have two different ...
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How to use %value% (from For iterator) in SQL expression of Calculate Field in ModelBuilder?

I have a shapefile with data of fish specimens and the coordinates where they were tagged for research purposes. One of the fields in the attribute table of these shapefiles is the fish length in ...
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Calculating order of points along a line

I have a shape file with transportation lines and another file with all bus stops along each line (with an attribute which links stops with specific lines to which they belong). I need to calculate ...
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Field Calculator decimal places - how can I limit them?

I've added a new column to an attribute table and performed an operation with the field calculator to populate the new column. The result is a column with a percentage. My problem isn't major but I ...
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Calculate difference between values in linear order using ArcGIS

The best way to describe this without knowing Python or VB jargon is to add these screenshots. I would like to emulate this Excel calculation in ArcMap10.1. MEAS is the distance along my route and ...
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How to set order of operations for Field Calculation in Network Analyst Evaluator Dialogue? [closed]

I desire to have a ratio calculated each time I create a new route. To get this ratio, I created and populated a field that multiplied the length of each segment by a designated number from 1-5, ...
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Calculating X and Y of line start and line end using ArcPy?

I have a series of polyline shapefiles and I am trying to automate the process of calculating the X and Y coordinates of the line start and line end using Python. I have added the 4 fields (startx, ...
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How to replace null values in attribute table ArcGIS 10.2

I have a string field 'Oneway' with three values '+' '-' and Null showing a street accessibility, I would like to replace them with values 'F' 'T' and null as the script for Network dataset expect ...
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How to count occurrences of one field grouped by values of another?

Is there a way of calculating the number of unique text strings in a field in ArcGIS 10.1? I have a number of repeated strings in this field, but would like to calculate the number of unique strings ...
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VB scripting in ArcGIS Field Calculator?

In my attribute tables field I am trying to get rid of the "&" in between names i.e. "John Adams & wife" and want it to say "John Adams and Wife" in all the attributes with "&". What is ...
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How do I add a hyphen to the Field Calculator to merge 2 columns?

I am trying to build a field calculator expression to merge two columns into one. I am looking for the word that makes it a range. Example: I have 2 columns in elevation, From and To. I want to ...
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ArcGIS 10/arcpy: Help needed with syntax for CalculateField_management in Python script

I need to use CalculateField_management in a Python script, and the calc expression needs to concatenate a runtime variable, a string, and a field (string) value. I have searched all over for ...
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Changing default parser in ArcGIS Field Calculator to Python?

Is there a way to change the default parser in the Field Calculator to Python? So annoying to always change now that I'm trying to move away from using VBScript... I'm using ArcGIS 10.1 for ...
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How to find/replace element in field with Field Calculator

I just want to perform the following operation done in Matlab into the Field Calculator using Python: p(p==0) = 0.001 ; p(p == 1) = 0.999; tVar = .5*log(p ./ (1 - p)) the operation consists of a ...
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If/then VBScript/Python code equivalent to SQL IN ('x','y',z') expression in ArcGIS Field Calculator?

we need just like the following, only with multiple records selected... have tried the "xyz" in (1,2,3,4,5) SQL code but of course VB Script wants something else. dim f2 if [field1] = "foo" then f2 ...
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Using IF operator with Python parser of ArcGIS Field Calculator?

I want to assign numbers to a certain types of building and I need to use field calculator. I tried many different versions of this and I still cant find whats wrong. Could you tell me where do I ...
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Cannot compute area of shapefile in field calculator of QGIS?

This shapefile represents the counties of NM. I am trying to compute the area of each polygon (yes, I know there is an area field, but this is a simpler example of a problem I'm having which doesn't ...
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How to insert a quotation mark through the Field Calculator of attribute table of a Shapefile?

I have a shapefile of polylines with information of diameter. But the problem is that i didn't enter the inch sign(") with the values of diameter. What would be the solution that qutation mark would ...
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Elseif Conditional Statement in QGIS Field Calculator

I am trying to write an ELSEIF conditional statement in QGIS Field Calculator (version 1.8.0). I have used an example I found online: CASE WHEN val < 0 THEN 'negative' WHEN val = 0 THEN ...
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using mod() with IF THEN field calculation

I am trying to use the field calculator to assign a "odd" or "even" value to a field of small integers. I usually do this with by selecting where: MOD([field],2) = 0 and then just calculating it ...
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563 views

Moving “last name” from last to first in Attribute Table of ArcGIS Desktop?

How do you get e.g. "John D. Doe" to "Doe, John D." in the AT using VB Scripting without going individually going through each line? I am using ArcGIS 9.3. I should note that not all the names are ...
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Find and Replace expression needed in Field Calculator ArcGIS 10

Looking for the Field Calculator code (Python preferred) to replace the last numeral values in a field using another field's values for entire attribute table. Please see screen shot here:
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381 views

Converting 12-hour time to 24-hour time using Field Calculator

Does anyone know how to convert string time formats in ArcMap v10.2 from 12-hour to 24-hour using a simple query in the Field Calculator? i.e. NO Python, NO editing in Excel, NO changing my Windows PC ...
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431 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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How to add attribute data up?

Sorry if this question is too simple/easy for you guys, but I'm still learning QGIS and pretty much teaching myself where I can. Is there a way to add data from 2 columns into one new column inside ...
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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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How to SUM field and then insert into NULL column?

I am only in the beginning stages of learning Python. I have a column, 'QUANTITY_SOLID', that I want to take the sum of all of its rows. I understand I can do this with 'SUMMARY_STATISTICS', but i'm ...
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Extract one GPS fix per day from data?

I am in the fortunate position of having 2 years worth of animal movement data. With such a large amount of data I would like to extract only one fix per day to make it easier to work with. Data = 14 ...
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How to Calculate Field in joined table using ArcPy?

I have to calculate a field based on another field in a joined table, but an error occurs: "Parameters are not valid. ERROR 000728: Field !Table_A.field_A! does not exist within table" My code: ...
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Field Calculator VB Script Codeblock IF statement syntax is wrong?

I can't figure out why the syntax is wrong in Field Calculator ArcMap 10. The complete codeblock is Dim CapitalDia As Number Dim TwagDia As Number Dim X As Number CapitalDia = [New_Pipe_S] TwagDia ...