Field calculators (which are available in QGIS, ArcGIS-related products, etc.) can recalculate the values of a single field, on all, or selected records within a table based on a symbolic expression.

learn more… | top users | synonyms

0
votes
1answer
229 views

Arcpy CalculateField using formatting syntax

I have 2 feature classes (FC) that I am merging together and then performing some field calculations on. The 1st FC has 100k+ records in it, and the second FC is a blank FC that I'm using as a ...
0
votes
2answers
205 views

Field Calculate with a function written in python within a larger python script

I'm writing a python program where I need to field calculate using a python function. The function takes two strings; one used for an if statement and the other to become an integer complete a simple ...
0
votes
3answers
295 views

Why does CalculateField set values to <Null> when output extent is in a different coordinate system?

I'm quite new to ArcGIS, and now I have to work on a script that goes through a list of feature classes to: add a field to their attribute table and fill that field with a number that I retrieve ...
0
votes
1answer
1k views

How to search text string and select item in QGIS?

I have a table attribute with complete roads name. I have to search items by digiting a part of the road name and I need to colour all the items selected. eg: ROAD NAME: / road 01 / road 02 / road 11 ...
0
votes
1answer
120 views

Trying (+ failing) to use a Function in Field Calculator

I'm trying to populate a field using a function. When I run this in Pyscripter, it works fine: d = {} # Function # def find_dups(val): d[val] = d.setdefault(val, -1) + 1 return d[val] # ...
0
votes
1answer
726 views

How to calculate polygon areas in acres or square miles instead of feet?

I have a layer in State Plane NAD83. When I use "Vector|Geometry Tools|Add/export geometry columns" or Field Calculator they both create the area in feet. What if I want acres or square miles? Thanks ...
0
votes
3answers
468 views

How can I easily detect gaps in a polyline using arcmap 10.0 (arcview license)?

I'm making routes by selecting links from a streets layer which I export as a new temporarely layer in arcmap 10. This layer which I call route_temp unfortunately can be very long and contain gaps, ...
0
votes
1answer
324 views

Add sequence numbering based on attributes in a table [duplicate]

Is there a way to auto populate a sequence of numbers based on another attribute in a table? For example, if field "Name" has a sequence of numbers from 1 to 10, and I want to number all the rows in ...
0
votes
2answers
2k views

Replacing NULL values in geodatabase table?

How do you update NULL values within a geodatabase table using the ArcGIS Field Calculator (service pack 4) without changing other values to NULL? I've tried the suggestions on this previous ...
0
votes
2answers
93 views

Writing Python script in Field Calculator in ArcGIS Desktop?

I'm a programmer, I have programmed in C#, Java, but not with Python. And I'm not a geographic worker. How can I write a python script into Field Calculator to be able to check the other column value. ...
0
votes
1answer
70 views

Painfully slow performance with Join and Calculate Field

I have a point layer and a table with approximately 100 fields. I need to join the table to the point layer based on a key field and create a new shapefile / feature class. This script has been ...
0
votes
2answers
88 views

How to calculate cumulative decreasing sum in ArcGIS-10.2

I need to calculate the cumulative decreasing sum as a field in a rasters attribute table. The cumulative decreasing sum is the accumulation of the last values to the first, so it is basically the ...
0
votes
1answer
48 views

Field Calculator not showing some fields

When I open my attribute table, click on a column, and select Field Calculator it opens and doesn't list all of the Fields in my attribute table. Why can't Field Calculator find these Fields?
0
votes
1answer
69 views

What is the syntax for Python 2.7 to permanent display in percent in a field column?

What is the syntax to build to calculate field, for example, Acres to Percent? 841173.00 to 82 % What I want the field column in Percent to be display numbers with percent with the alignment to ...
0
votes
1answer
33 views

Interaction with two variables as parameters, saving the raster properties output into a table (.dbf)

The draft of the model below TASK: I need to calculate the percentage of river channel that is covered with shadow in each timestep RESOURCS: I have values for azimuth and elevation of the sun ...
0
votes
1answer
137 views

Replacing attribute table entries using python script. Script needed

I am using ArcMap 10 from ArcGIS 10.2.1 package. I got an attribute table, with few collumns. I need to replace some column "String_A" entries with newer "String_B" entries, in the same row. In both ...
0
votes
1answer
91 views

How to calculate/record attachments' file names using Field Calculator?

I have a point feature class containing attachments corresponding to jpg files (sometime more than one jpg per feature). I would like to use the "field calculator" to calculate/record a new field that ...
0
votes
1answer
100 views

QGIS: graphical-modeler to calculate area of polygons

I'm trying to calculate the area of polygons using the field-calculator in QGIS (2.0.1). If I do this manualy it works fine, but if I do this using the graphical-modeler I get NULL as area for every ...
0
votes
1answer
756 views

how to use the TRIM function in field calculator

I need to remove leading spaces in a field in my attribute table, but not how to do it from the field calculator
0
votes
1answer
108 views

CalculateField_management - updating fields with X and Y coordinates for start and end of line

I've searched all the help documents and can't see where my script is going wrong. I've tried adding the fields as FLOAT, replacing "PYTHON_9_3" with just "PYTHON" but it just doesn't work. The ...
0
votes
1answer
106 views

ArcMap Calculate Field..if “text” in !Field!

Is it possible to use Field Calculator in ArcGIS to add text to a new field based on an if in statement? Example: In an attribute table I have a some fields called !X!, !Y!, !Z! where "A (xx%)", "B ...
0
votes
1answer
35 views

Wich is the way to create serial field following alphabetical order with QGIS?

I have a field with names, a string field, and I want to create another one with serial content following the alphabetical order. I have this: -------- |Field1| -------- | B | -------- | C ...
0
votes
2answers
300 views

Field calculator error and Geoprocessing results window empty

I need to use the field caculator for a new field that I have just added but I keep getting the following error: The problem is that when I open the Geoprocessing Results window is just completly ...
0
votes
1answer
80 views

Can QGIS report/calculate areas/perimeters of individual polygon components within multipart shapefile?

Can QGIS report/calculate the areas/perimeters of individual polygon components within a multipart shapefile without using the "explode" vector tool to generate a new file? using QGIS 2.2.0 on ...
0
votes
1answer
112 views

Is it possible to calculate a value based on values of another row?

I have a point shape file in qgis. For one of the attributes, I would like to offset the values, i.e. the value for point 1 goes to point 10, the value for point 2 goes to point 11 and so on. I see ...
0
votes
1answer
316 views

Conditional Calculation of a text Field Value Based on antoher text field value ArcGIS10.1 [duplicate]

I Created a new field to explain some zoning codes in an attribute Table. I basically want the new field "Zone" to have a string value based on the field "Zoning" For example if the "Zoning" field ...
0
votes
1answer
141 views

Problem in calculating length

I am Digitizing road line in India using open layer plugin.When I calculate the length of line using field calculator it gives me the result in millimeter . I thought it is the projection problem and ...
0
votes
1answer
223 views

Python: using CalculateField_management for duplicating attributes with a double quotation mark

I am writing a python script which duplicates a field. The field contains names of pipelines but some of these names has double quotation (ex. 8" NGL PIPELINE). I have created a new field and trying ...
0
votes
4answers
160 views

How can I calculate different polygons by different attributes?

I'm doing my master thesis and want to calculate different polygons (in QGIS 1.8 for Mac) in four different columns which I defined by different attributes. i.e. some of the attributes in the first ...
0
votes
1answer
75 views

Table calculation in QGis

I have a shape file with the attribute "yield". I need to know the math difference between yield (id1) and yield (id2)...then yield (id2) and yield (id3) and so on... I hope you understand what I ...
0
votes
1answer
276 views

How to calculate the area of the convex hull of a points layer

I have a shapefile in QGIS that I have created by importing a CSV of points, using Points2One to convert to a shapefile and then importing the shape. I am now trying to calculate the are of the shape ...
0
votes
2answers
123 views

Stacking attributes in a text field

I am trying to stack my text in an attribute table using the field calculator, but it does not seem to be working. My field name is: Facilities. My attributes are in this format: Public ...
0
votes
1answer
161 views

FieldPyculator Plugin - How to concatenate fields?

How can i concatenate two fields using pyculator plugin? There is any document with all pyculator functions that i can use in "field expression"?
0
votes
2answers
847 views

How to auto populate multiple fields in attribute table?

i have Feature Class Buildings, it has many fields like ...
0
votes
1answer
660 views

Null output from field calculator code block

I have a simple calculation to compare two columns and populate a new column with the lower value but I am getting null output...any ideas? expression ...
0
votes
1answer
13 views

Copying the numeric portion of an address to a new field

I'm attempting to copy just the numeric portion of a street address into a new table using the Field Calculator in QGIS. The expression I'm trying to use is: left( "SITE_ADDR", strpos( "SITE_ADDR", ...
0
votes
0answers
21 views

Python script to get count of features that meet a certain criteria [duplicate]

I am in search of a Python script for use in the ArcGIS Field Calculator to return the number of features that meet a certain criteria. Here's where I am getting stuck: def ...
0
votes
0answers
85 views

Python script to get feature count in a feature class that fall in a specific range

I need to write a Python script to be used in the ArcGIS Field Calculator that will return a feature count for values between a range defined by the values in two other columns. Here is a graphic ...
0
votes
1answer
20 views

Is there a way to automate field calculations for ArcGIS Server?

I have a field that I'd like to be concatenated with each new objectID when a feature is created in my feature service. Workflow: Feature added, already contains objectID. Would like my Service ...
0
votes
0answers
67 views

Why will my field calculator python function always return Null if any inputs are Null?

I've written a simple python function that outputs a list based on yes/no fields. It appends a word to a list if it has a "yes" in another column then writes the list, formatted according to the ...
0
votes
0answers
43 views

Concatenate an object ID and string to publish gp service with field calculator?

I have a simple model which concatenates and object id and a string, to create something like 1SRS2567, the concatenate function of OID and the string field are able to be passed in VB, but not ...
0
votes
0answers
60 views

calculating decimal degrees from coordinates found in an excel table

What is the exact syntax to use when calculating decimal degrees in the field calculator? I know the general formula {i.e. Degree + (minute/60) + (second/3600)} but how do I put this into the gis? I ...
0
votes
0answers
25 views

Assigning values to new field using field calculator? [duplicate]

I have a polygon with attributes showing the service area of 300m from a busstop as well as 600m from a busstop. Attribute fields > From Break with values 0 and some with values 300 Attribute fields > ...
0
votes
0answers
35 views

Field is not nullable but Field is nullable Box is checked

I had this problem already a couple of times. I add a Field (float) to an existing feature class, the Field is Nullable is arleady checked. But performing a calculation with the Field Calculator on it ...
0
votes
2answers
109 views

ModelBuilder - How to calculate Field using part of path name

I am trying to calculate a field using part of the feature class path name (specifically, the last three characters of the geodatabase name). Is this possible? I've tried using the parse path tool and ...
0
votes
0answers
127 views

Using Code Block in Field Calculator with ArcObjects (VB.NET)

I'm having trouble using a code block in the Field Calculator with ArcObjects. Ideally, I'd like to be able to read a text file which contains the Python code for the code block. I've tested this code ...
0
votes
2answers
748 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 ...
0
votes
0answers
44 views

Calculating rows in a attribute table of a point shape with QGis or Saga

I have a point shape with an attribut ("test"). I need to calculate the sum of the 1st four (id 1-4) "test" values and then the next 4 (id 5-8). Is there a chance to calculate this with the field ...
0
votes
1answer
261 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. ...
0
votes
1answer
46 views

Formatting Cells in ArcMap

I am trying to join tables together and need the PLSS to line up correctly. In my table with geometries I have "CO060020N0650W0SN330" in a field. I want to make a new column and make it say 2N65W33 ...