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)

3
votes
1answer
106 views

QGIS Field Calculator functions

Using QGIS 2.12.3, within the Field Calculator "Geometry" section, there are certain functions, such as "area", that also have a corresponding term beginning with a dollar sign, i.e. "$area". I don't ...
1
vote
1answer
40 views

Iterating through list of fields using field calculator?

import arcpy, sys, itertools arcpy.env.workspace = r'path to geodatabase' fields1 = ['gearqty', 'cnemarea', 'fzone', 'qdsq', 'tensmsq', 'crew', 'nanglers', 'port', 'totalquant', 'trip_days', ...
1
vote
0answers
60 views

Converting Atn function of VB Script for Python parser of ArcGIS Field Calculator? [closed]

I would like to convert the Atn function (which returns the arctangent of a number) of VB Script to Python but I cannot find exactly the same function. Any help? I want to convert the slope of ...
0
votes
2answers
73 views

Calculating percentages in ArcGIS field calculator gives TypeError: 'float' object is not iterable?

I am trying to calculate the percent AREA in each class. I have created a new percentage field and have tried to populate it using the following equation in python in the calculate field tool. ...
3
votes
2answers
67 views

Why is VBS If Then Label Expression not working?

I am trying to label a field based on other field. For [TYPE] = "PRIMARY", the [LABEL] is having this structure: "TAN80901B" For [TYPE] = "SECONDARY", the [LABEL] is like this: "TAN80901C/D20b" I ...
1
vote
1answer
34 views

Calculating average values of condition or receive values from a table for calculation in another table

I have a table with data (in this example the field "TSS"), a field time corresponds to the data for each point. I want to create a field with the mean values for each point all time values, without ...
1
vote
2answers
92 views

Calculate field more wisely

I first classified firstCol into groups and then I want to give the groups with different weighted values in another field, SecondCol. I will need to give different weighted values very often. I find ...
2
votes
3answers
139 views

If else if in ArcMap Field Calculator (Python)

Help! I think I am missing something that must be so obvious but I cannot figure out what I am doing wrong. Here's some background: I have one short integer field (MajAspNum) that has values ...
0
votes
0answers
27 views

Calculate field for each Feature Class in Dataset using Python and different arguments

I have Dataset with Feature Classes in it. I'm building this in ModelBuilder. I want to calculate new field (SMB_ID) depending on attributes for each feature class. I was trying to make it simple ...
2
votes
4answers
96 views

Calculate Length Totals in ArcGIS based on field values

I am having trouble finding the right words to describe this problem but here goes: I have 3 values (120,270,380) in my field called operatingvolt for every segment of conductor. Each segment of ...
3
votes
1answer
46 views

QGIS - Field Calculator: scale_linear gives unexpected result

When I try to use scale_linear, its output isn't as I expected. My values are from 1 to 16, so I set domain_min = 1 and domain_max = 16. I want to interpolate to interval from 1 to 4 so I set ...
2
votes
1answer
69 views

Rename cells in Attribute Table to 'XXX.$ID'

I feel like this should be easy to answer, but I can't get it to work for me. I need to edit the attribute table of a .gpx file before I load it into my GPS, in order to label the points. I can rename ...
3
votes
3answers
81 views

Can't replace attribute with field calculator

I have an attribute table where one of the columns (laeskaerm) has been edited/created by checkboxes on 2 different machines. Result: it contains both 1, 0, true, false and NULL I'd like to replace ...
1
vote
2answers
60 views

How to compute the distance from the current polygon centroid to another in QGIS field calculator?

There is layer with polygons. I want to save in new field distance of every polygon's centroid to centroid of one particular polygon. To do this I should write some expression like this: ...
1
vote
1answer
60 views

How to edit virtual field definitions in QGIS?

I have a virtual field in QGIS. The values are updates depending another column with a concatenate CASE statements. I would like to edit this statement but I cannot see it. I have attempted to use ...
2
votes
1answer
81 views

QGIS processing toolbox: fieldcalculator - update only selected features is not possible

I am working on a model where I need some calculations on only some selected features. In the normal fieldcalculator you can check 'only update ... selected features'. When using the fieldcalculator ...
2
votes
1answer
121 views

Using ArcMap Field Calculator to count number of identical values?

I have a file with an attribute table with data in 3 columns, and would like to use field calculator to populate a 4th column. The data is integer numbers between 0 and 56. I want the new column to ...
1
vote
1answer
52 views

Polygon Surface Area Calculator in different map projection(s)

I'm simply looking for an online tool or a utility to calculate the surface area of the same polygon (i.e shapefile) in different projection (projected and geographic projection system) systems. It ...
-3
votes
1answer
51 views

Calculating field gives invalid expression in QGIS?

I am a new user of QGIS and I want to add a new field in my attribute table named densite which can be calculated by POP(population) / Area, in Field Calculator, I wrote POP/Area no result !! invalid ...
2
votes
3answers
55 views

Add value to entire column in attributes

Is there a way to add a value to the entire column? I don't think i can use raster calculator because it's a text i want to add, the letter "B". Here is a picture. This is what happends when i use ...
3
votes
2answers
41 views

Using Field Calculator vb to check for name with /n in the string?

I am calculating values for a field (Score) based upon the names from another field (Modified). One name is "blaugh\nblaugh". Field Calculator keeps treating the name as having a new line command. I ...
-1
votes
1answer
28 views

calculating sq ft of an picture image with only a scale bar as reference

I have an architectural image of a building. However, I had to change the blueprint and extend the walls out further increasing the total sq.ft., and simply for the means of drawing out the new ...
1
vote
1answer
45 views

failed to Writing conditional (if/then) statements into Field Calculator of ArcGIS for Desktop using Python parser?

I wrote this following several examples but it is still wrong. I need to populate a new field based on 5 ranges of values. def marks(Wards for try.JHRatio ): if (Wards for try.JHRatio <= ...
1
vote
0answers
57 views

Calculate z score into new field in ModelBuilder? [closed]

I'm trying to calculate z scores for a given column. I am working with a shapefile, that contains fields like percent poverty, percent tree canopy and temperature. My ultimate goal is to add new ...
1
vote
2answers
134 views

“CountIf” or alternative function in ArcMap field calculator?

Within ArcMap 10.3 field calculator, I am looking to count the number of features in a column that match the current value, and output that count. Ideally, the output would look like this: Number ...
0
votes
1answer
89 views

How calculate sequential values based on group field?

In field calculator i calculate sequential values in field [ORDER_ID] What need change in script to calculate sequential values based on group field [GROUP_ID]. I select values manually and use ...
2
votes
3answers
59 views

Stacking multiple selected points in ArcGIS

I would like to find a way to stack multiple selected points in ArcGIS, either using the field calculator or python script. For example, I want to snap all points representing houses on a street into ...
1
vote
0answers
64 views

Replacing Null values with field calculator

My goal is to use the field calculator to replace null values. I am trying to replace nulls in the ToDate_Time with the FmDate_Time. When I run the code below the results window says that it worked ...
2
votes
3answers
272 views

How to get around “The field is not nullable” error?

I have a shapefile of lines. I want the angle of every line calculated in a field. I am using the script below in arcmap, but when it encounters a line that is horizontal, it stops calculating any ...
2
votes
1answer
47 views

Loading Features prompt in QGIS?

I'm currently working on a dataset with 3.8m records. I have a very simple expression to update a field that I want to execute using the Field Calculator, while having the Attribute Table open. Do I ...
2
votes
2answers
106 views

Formatting SQL expression for calculate field (management) tool?

I am trying to take the population census tract and calculate the percentage of population by each census tract in the field (Populati_2). To do this I'm creating a new field with the total sum of the ...
1
vote
3answers
207 views

Using Field Calculator to compare two fields in att table and returning if equal or not in ArcGIS for Desktop?

Using 10.2.2 I am attempting to compare two fields in an attribute table using the Field Calculator. I'd like to return a value of '0' if they are equal and a value of '1' if they are not equal. ...
0
votes
1answer
75 views

Calculate percentages with field calculator in arcgis?

I am trying to calculate the percentage of each the area of each polygon in the selected area. I tried using ( math.fsum(!shape.area!) / !PolygonArea! )*100 and other codes but I cannot make it work. ...
0
votes
2answers
35 views

update cursor based on location

I'm working on a python script for ArcGIS 10.2/10.3. What I want is to automatically fill in a field of a point layer based on the location of that point in relation to a polygon layer. Say I have a ...
1
vote
2answers
142 views

Update multiple fields/columns in QGIS

I need to update fields in attribute table of a vector using QGIS. I use field calculator for each field, but i have too many fields (and too many vectors also) and i need to program the task. The ...
1
vote
0answers
11 views

How to calculate area percentage from polygons from one shapefile within another? [duplicate]

I'm working on a project where I have to create python code that takes land-use data and adds a percentage field for each land-use category in a Census Tract shapefile. I've been trying to work with ...
0
votes
1answer
45 views

Creating IDs for multiple features in Python Parser of ArcGIS Field Calculator?

Does anyone know how to create ID numbers for multiple features using python? For example; (IDs being the object ID, Name and object ID being two different fields) Names //// IDs Street 01 River ...
1
vote
1answer
25 views

Clearing Calculate Value before Model Run in ArcGIS ModelBuilder?

I am using ArcGIS 10.2 for Desktop. I have a model which contains several branches, which branch should run is based on the results of an earlier stage in the model. If the first stage of the model ...
2
votes
1answer
114 views

Populating attribute table string field with values from long field using vbScript in ArcGIS Field Calculator?

I want to calculate the field "area_type" with text depending on numbers from the "Value" field. I have tried with the following VB-script in "Field Calculator" but am getting this error message: ...
1
vote
2answers
80 views

Using nested If statement in Python parser of ArcGIS Field Calculator?

I'm trying to use field calculator to assign values to a new field I created. I wan't to assign the value from the first field unless that field is empty, if it is empty use field 2, if that is empty ...
1
vote
1answer
37 views

QGIS field-calculator: set attributes to 1 if country name is in a list of values

In a country table, I create a region field, ECOWAS, with 1 if the country belongs to the regions 'ECOWAS', 0 else. Country names are in the field "sovereignt". How can I build a field-calculator ...
0
votes
2answers
58 views

Iterating field calculations in arcpy

I was successful in adding multiple fields but had trouble running multiple field calculations in a loop. Now what I want is loop through these existing fields listed in mult_fields variable and fill ...
1
vote
1answer
44 views

Field calculations and existing domains

I have feature layer which needs to be updated with new attribute information. The text field I need to populate already has an established coded domain. I need to update hundreds of records and don't ...
0
votes
3answers
112 views

Python code help for ArcGIS Field Calculator tool (Model Builder)

Is there any python code that: 1st, sort a column (example name by alphabet) 2nd, grab the first cell of sorted column and assigned it to a variable like A=.. I need all of this to be done in field ...
1
vote
2answers
123 views

Replicating Summary Statistics tool with case field using own calculation within ModelBuilder?

I thought this would be a simple problem to solve, by my googling hasn't provided the answers so far. I have created a near table (Using the 'Generate Near Table' in Arc) comparing two sets of ...
2
votes
2answers
60 views

Sequential attribute field calculations with null values using Arcpy

I have a series of x,y co-ordinates converted from a .ply file. I was able to extract the file into a suitable x,y format for arcmap, the issue I have is that they are co-ordinate points representing ...
1
vote
0answers
64 views

Converting UTM to Lat Long inside a Game Engine(Untiy 3d)

This is my first post on Stack Exchange. I have exhausted my research through the game engine forums, so I am trying this forum since you guys seem to be the experts. I have an external device that ...
1
vote
1answer
56 views

How do I round the coordinates of a point before insert into attribute table in ArcGIS?

Until now I doing the following steps to get rounded coordinates: create a new x and y column in the attribute table use Calculate Geometry round the column value with the Field Calculator using VBS ...
2
votes
1answer
104 views

Running ArcGIS field calculation using Python with algebraic expression using other field values as variables?

I'm trying to run a field calculation using multiple fields in a table as well as independent numeric values with python code in the field calculator window. I've included the first 7 lines of the ...
0
votes
1answer
68 views

What expression needed for universal naming of parts polygon feature class?

For example, i have n count of polygons and little parts of it. I want in field [Name] get string: "PNum1(1)". where "1" - number of main polygon [Num], "(1)" - number of part of main polygon ...