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.

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81 views

Replace characters

How to remove a special number of characters of a string, e.g. the last 7 characters? And how to join them as the first characters to the string of another field? Thank you for VBS and Python synthax ...
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1answer
60 views

Decimal Degree data erases itself between edit sessions in QGIS

I have a shapefile with point data. I calculate the $x and $y of the points successfully I save the changes and close the edit session. Once I reopen the attribute table, the data after the decimal ...
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2answers
72 views

python add fields that may have NULL values

I would like to use python 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. ...
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1answer
54 views

Arcpy Calculate Field Formatting Syntax

I am trying to field calculate a double field (PID) to a new string field (PIN). Using: qry = '"139-{}".format(!PID!)' arcpy.CalculateField_management(out, "PIN", qry, "PYTHON") Given a PID = ...
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144 views

How to copy values from field to another using arcpy?

Can some one please let me know how I can do simple field calculation like Copying From "A" to "B" in ArcPy? I have found lots os example on web which they all used extra expression and they were ...
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72 views

Populate an attribute table field using the 'startswith function

I am hoping that someone may be able to help me. I am new to ArcGIS, and even newer to Python. Working in ArcGIS 10.1, I have done is created a new text field in an attribute table, which I have ...
2
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1answer
313 views

Calculating a field based on two other fields, if they exist [duplicate]

I'm using ModelBuilder to iterate through ~800 shapefiles to add and calculate a new field (I'll call it Field_A). Field_A needs to be populated by either Field_B or Field_C, whichever exists. Half of ...
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2answers
696 views

Use Feature Class “Name” from Iterate Feature Classes to Calculate Field with Model Builder 10.1

My goal is to create shapefile that contains merged feature classes from a geodatabase. I would like for there to be a new field in the resulting shapefile that contains the name of the original ...
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1answer
137 views

Need a Python field calculation that works like the DatePart( ) VB Function

I have a field called Abandoned Year (short integer data type) that I am trying to populate with a four digit year from a column called Decommission Date (Date data type). I have done this in the ...
2
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1answer
104 views

Syntax question for ArcGIS ICalculator object

This is a silly question, but I have this code snippet that I can't figure out: 'Define a calculator for NewArea field pCalculator = New Calculator With pCalculator .Cursor = pCursor ...
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3answers
767 views

Field calculator script not working

I am trying to do the following in the field calculator in ArcGIS 10 if [IncdStDir] = " " then [IncdStNo] &" " & [IncdStName] &" " & [IncdStSfx] else [IncdStNo] &" " & ...
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2answers
203 views

How to use DateDiff() Function across day transition in ArcGIS Field Calculator?

I am trying to calculate the time difference between two fields using the DateDiff() function in minutes. I have successfully calculated the times that fall within the same day but I am having trouble ...
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2answers
111 views

Expression to calculate and sort data from several layers into one layer

I am trying to develop an expression whereby one layer can add data from 2 other layers and then rank them, is this possible? I have also tried the problem with using just 1 layer but I cannot work ...
2
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1answer
211 views

How to make autoIncrement number start with (001…009, 011…099)?

i have a challenge with my time in my work, i have feature class called "Parcel" storing many data, i generated an autoIncrement number by using field calculator, in field "parcel code" Expression: ...
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1answer
163 views

How to assign values to field using if/then logic involving multiple fields?

I want to run a field calculation on a string field named [territory] that first looks at a string field [majr_src] to see if there is a value other than "NONE", if so [territory] = [majr_src]. If ...
2
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2answers
157 views

Correctly calculating attribute table column in gvSIG

I am trying to conduct a multicriteria evaluation, and it is necessary to check the compatibility of two different land-use types that I have in seperate layers. I am working in gvSIG 1.12, and have a ...
2
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3answers
475 views

Python script for identifying duplicate records (follow up)

I am trying to calculate a field that marks duplicates and sequentially numbers them. I am using the code below that I found here: Generating sequential numbering for duplicate values in a field ...
2
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1answer
143 views

Using Sum() or something similar with CalculateField_management and FieldLists

I need some help with using variables with CalculateField_management tool. I've tried several different scenarios but don't seem to have any luck. What I have is a list of fields containing water ...
2
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1answer
138 views

Using update cursor on a field with a domain

I have been replacing field calculations with python update cursors in many of my work flows and today I ran into a problem. The fields being updated have an attribute domain. so now, when I ...
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2answers
1k views

Using Value from Iterate Feature Selection to Calculate Field in ArcMap 10.1 ModelBuilder

I have two polygon feature classes, an alignment layer and a parcels layer. I am trying to use ModelBuilder to create a tool that will do the follow: iterate through groups in a single field of a ...
2
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1answer
56 views

using “abs()” function in QGIS field calculator?

I'm pretty new to GIS in general and I'm trying to take an absolute value of the difference between two fields in field calculator when creating a new field, but using ABS () returns an invalid ...
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1answer
89 views

How to convert QGIS Field Calculation to ArcGIS?

I have a field calculator expression I use in QGIS to generate unique IDs that are sequential, but start with a text string. I now need to perform the same thing in ArcGIS, but I am unsure of how to ...
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1answer
705 views

Incorrect field name resulted in RuntimeError: ERROR 999999 (Also, better code for adding and calculating fields)

This is the bottom half of my code (and it's been edited somewhat to share publicly). The code works perfectly fine when the fieldList has only three fields in it, but when I populate it with all 108 ...
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1answer
803 views

Using the Field Calculator in a Domain field

I have a coded domain field with 10 dropdown options. Possible choices include integers and text. I need to change a selection of 250 features (which have differing values) to the same value. This ...
2
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1answer
191 views

Mysterious Invalid Syntax in Field Calculation

I'm trying to calculate a field in Model Builder using the Calculate Field tool. I'm using the following code block and expression in the calculation, but am getting an "invalid syntax (, line 1)" ...
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1answer
551 views

Using Python in the Field Calculator, how do I refer to a field in another shapefile?

I want to compare the changes in geometry between two shapefiles (of election districts in NYC. One is from 2001 and the other 2005). I am attempting to calculate a new field in the 2005 shapefile ...
2
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1answer
979 views

QGIS field-calculator replace function

I've got a Shapefile containing contourlines which I would like to style differently according to their value. For that reason I created a field named "100s" where I would like to give values from ...
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1answer
240 views

How to implent a “maketrans” python function on field calculator

i'm traying to implent python string translate function at field calculatore http://www.tutorialspoint.com/python/string_translate.htm in order to fix hebrew imported from cad. here is the code - def ...
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1answer
192 views

Why isn't this Python calculation working correctly?

I want to label the source files for a unified shapefile, and there are three respective columns for each. If there is no value in the column, there is no data from that source; if there is a value in ...
2
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1answer
1k views

How to populate a field with the max M value of a feature using Python in Field Calculator?

I need to calculate the max M value for a line feature using Python in ArcGIS 10 Field Calculator but I cannot figure it out. In 9.3 I used the follow VBA expression… **Pre-Logic VBA Script Code:** ...
2
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1answer
94 views

How do I add a column in an attribute table using QGIS graphical modeler?

I have started to make a model in QGIS 2.2 graphical modeler. I have made a buffer around a polyline and used it to clip a polygon layer. So far i t works. But the next step is to add a new column ...
2
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1answer
129 views

Batch Update Fields in Field Calculator or Model

I have a dataset of block-level census data that I clipped to an Illinois State Senate district. To update the data (e.g. for population) I'm applying an area multiplier, i.e taking the area of each ...
2
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1answer
204 views

How can I refer to a model variable in a Field Calculator or Pyculator formula?

I am new to QGIS 2.0.1 Modeler (Sextante) and not very able in Python programming. My question regard the use of field calculator (or advanced python field calculator) inside the modeler. Is it ...
2
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2answers
240 views

Is the derived area/length/xy values of a polygon/polyline layer in QGIS usable?

I have a raster that is projected to a state plane CRS and I am adding polygon/polyline shapefiles that are projected to WGS84. On the fly transformation is set to reproject to my raster CRS. When I ...
2
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1answer
257 views

Generating sequential numbering for duplicate values in a field sorted by ObjectID

I am trying to figure out a solution to an field calculation problem. What I'm trying to do is automatically (using either ArcPy or the Field Calculator) generate sequential numbers, beginning at 1, ...
2
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2answers
48 views

How to flag parcels as being within stop type dependent distance of transit stops?

first question here! I have a parcel layer and a transit stop layer. The transit stop layer has different bus stops, light rail stops, etc. I want to add to my parcel layer attribute table fields ...
2
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2answers
135 views

How to calculate land cover inside the buffer zones?

In one Shape file I have created 1200 buffer zones Around coordinates. I created a field and calculated the buffer zones area in hectares. Then I clipped different landcover layers to the buffer ...
2
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2answers
389 views

Field calculator or update cursor?

I have a feature class in which one field (let's call it "Field_A"), as yet empty, is to be populated by the contents of another field ("Field_B") multiplied by a certain number (I'll call it the ...
2
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1answer
2k views

How to combine If Then with InStr in ArcMap field calculator?

I want to write an if then in field calculator that tests if a field in the attribute table contains one of several versions of another string (the versions vary by capitalization). Trouble is, I ...
2
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1answer
589 views

Cursors and Field calculation - Python 2.5 - ArcGis 9.3

I hope my question is not redundant. I wrote a script to Update a table using two imbricate cursors. The goal was 1) to read a records, update some of its values 2) Make a selection based on this ...
2
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1answer
561 views

Counting occurrences across a record in ArcGIS 10.0

I'm a student at Millersville University, PA studying for a BA in Geography with a concentration in GIS. I've stumbled across this site for questions I've had over the past year or so with getting ...
2
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2answers
2k views

Multiple input tables for Add Field in ModelBuilder

My model requires field1 to be added to fc1 and fc2, and then calculated according to a Python expression calc1. field2 is then added to fc2, and calculated using calc1. How do I add the multiple ...
2
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1answer
59 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 ...
2
votes
1answer
252 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 ...
2
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2answers
64 views

What's the use of the buffer function in field calculator?

I'm trying to find out how the buffer command in the filed calculator works. I tried to create a new field to my point shapefile (integer) with the following: buffer ($geometry, 100) but no ...
2
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44 views

Using Field Calculator to Convert Data Type In Field

I am trying to convert a field that is listed as "String" because it was imported into QGIS as a CSV (rural poverty population percentages by county in NC). I need to convert the percentages field ...
2
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2answers
126 views

How to trim strings in Field Calculator?

I am currently working on a County plat book and am in the process of prepping the "Owner_Nm" field that will serve as my annotation layer. I am trying to whittle down the owner names, based on ...
2
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28 views

How to save complex expressions in QGIS Field Calculator? [duplicate]

I have been debugging some long case expressions in the field calculator and getting frustrated because I have to remember to copy the expression before I test it otherwise I end up having to reenter ...
2
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1answer
404 views

Field Calculator Runs In IDLE (2.6.5) but not ArcGIS 10 SP3

just wondering if anyone else is having issues with the field calculator in ArcGIS 10 SP3. In the following code I do a pretty simple field calculation with a variable (an array) as one of the ...
2
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2answers
218 views

Can anyone tell me why my field calculator is returning this error?

All I am trying to do is pull into a text field, a section of another text field via: fieldB = !fieldA![some_index:other_index] However I keep receiving the error below and I can't figure out why. ...