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.

learn more… | top users | synonyms (1)

5
votes
2answers
2k views

Arc 10 field calculator scripts

I need scripts for the field calculator that: extracts the first word from a column, i.e. "Jones School" - "Jones", and A script that will capitalize this new field, "Jones" - "JONES". This is Arc ...
5
votes
5answers
578 views

How to combine text and integers in a string field?

I have field with numbers in it (field type: double, number format: numeric) and I need to create a new field and put text in front of the numbers. I know that I need to add a new string field, but ...
5
votes
1answer
4k views

Python If else statements

I'm trying to populate a field from another. The catch is that it isn't 1 or 2 values. If my field A = 4 then I want it to return field B to 0. But if Field A is 1, 2 or 3 then I want the user to be ...
5
votes
1answer
3k views

Converting state name abbreviations to full names using ArcGIS Field Calculator?

I have a data table with columns that includes city names (ex: San Jose) and state name abbreviations (ex: CA). Is there a way to define the state names as their full names (i.e., CA = California) and ...
5
votes
1answer
5k views

Using VBA in ArcMap field calculator?

I am trying to use ArcMap's Field Calculator to populate values in a column based on a value in another column. So, in pseudo-code: if [field1] = 'Foo' set [field2] = 'Bar' endif Something like ...
5
votes
2answers
472 views

Way to find minimum value from a group of values - QGIS?

I'm wondering if there is a way to find the minimum value of a group within QGIS? Basically I need to find the minimum distance of each unique value in a table of about 5000 records. I can do the ...
5
votes
5answers
4k views

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 ...
5
votes
1answer
522 views

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 ...
5
votes
2answers
873 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 ...
5
votes
2answers
344 views

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 ...
5
votes
2answers
1k views

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 ...
5
votes
2answers
435 views

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 ...
5
votes
1answer
466 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 ...
5
votes
1answer
4k views

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 ...
5
votes
2answers
268 views

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 ...
5
votes
3answers
9k views

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: ...
5
votes
1answer
102 views

Field Calculator text field to new shapefile

I have point features being selected by a polygon feature and copied to their own shapefile. I also have certain values of the polygon feature being applied to the newly created point file. The ...
5
votes
4answers
1k views

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, ...
5
votes
1answer
8k views

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 ...
5
votes
1answer
201 views

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 ...
5
votes
2answers
246 views

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 ...
5
votes
2answers
768 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 ...
5
votes
1answer
3k views

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 :
5
votes
2answers
93 views

Why can't I multiply values from column named 'length' using field calculator via PyQGIS?

I want part of my plugin to multiple value of length and add it to table.Basing on this question: How to use QGIS field calculator in python? , I made script that works fine for some filed: I can ...
5
votes
2answers
237 views

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 ...
5
votes
2answers
2k views

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 ...
5
votes
2answers
1k views

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 ...
5
votes
1answer
688 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 ...
5
votes
3answers
154 views

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 ...
5
votes
1answer
1k views

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 ...
5
votes
3answers
531 views

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 ...
5
votes
4answers
529 views

Is there a way to close a geoprocessing operation when the dialog box has been hidden/pushed to the back of the window

Is there a way to close a geoprocessing operation when the dialog box has been hidden/pushed to the back of the windows? I ran a python process as VB Script and when the error message appeared I ...
5
votes
0answers
39 views

How to update null geometries from an attribute [duplicate]

I have a large point feature class and have realised that there are several hundred features with null geometry. Fortunately the coordinates are stored as an attribute. So What I need to do is update ...
5
votes
1answer
165 views

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 ...
5
votes
0answers
232 views

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, ...
4
votes
4answers
4k views

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, ...
4
votes
3answers
11k views

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 ...
4
votes
3answers
4k views

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 ...
4
votes
1answer
2k views

Adding hyphen in ArcGIS Field Calculator to merge two 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 ...
4
votes
1answer
1k views

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 ...
4
votes
3answers
6k views

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 ...
4
votes
2answers
442 views

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 ...
4
votes
3answers
489 views

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 ...
4
votes
2answers
6k views

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 ...
4
votes
3answers
222 views

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 ...
4
votes
1answer
583 views

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 ...
4
votes
4answers
3k views

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 ...
4
votes
1answer
12k views

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 ...
4
votes
2answers
4k views

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 ...
4
votes
3answers
587 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 ...