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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ArcGIS Field Calculator Python numbering rows of fishnet

I have a grid of 100*100 cells. I want to add to each cell a number representing the row it is in (like in excel). I added a field and want try to solve that with field calculator: The code is ...
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1answer
235 views

Is there a (better) way to debug Visual Basic Code Block in calculate field using ArcGIS?

From time to time, I have to use Visual Basic in Calculate field. As the code get bigger, the more complicated is to debug it. And ArcGIS (9.3) does not help as the error messages are, in the best ...
3
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1answer
51 views

Do pad functions of QGIS Field Calculator have bug?

I have this expression in the field calculator: regexp_replace('1', '^(\\d+)', rpad('\\1', 3, '0') ) gives 01 rather than 001 as expected. the *pad functions work fine when called outside ...
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56 views

Calculating a Unique ID on a Subgroup of Polygons

I would like to assign a unique ID to polygons in a dataset. The catch to my issue is that I would like polygons that fall within a polygon to have the same unique ID. My example is related to ...
2
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2answers
135 views

Round decimal number in ArcGIS10.1

How can I round the decimal number in a table in Arcmap: e.g. how can I set it to 2.60?
2
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3answers
212 views

Calculate X and Y of line start and line end in Python? ArcGIS 10.1

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, ...
2
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3answers
100 views

ArcGIS 10.1 : Returning shape.area in my code block

I try to calculate a field using an 'if' statement in the field calculator. Here is my code : " #Expression MyField_2 = def Reclass(!MyField_1!) #Parser Python 9.3 #Code Block def ...
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1answer
332 views

Why does this python function return a value of 0 in field calculator?

I am trying to calculate the percentage of a total which the median value makes. I have a column with the median column labelled (i.e. 1st,2nd,3rd,4th column is median), the columns of values and the ...
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3answers
228 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 ...
2
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2answers
266 views

Why is QGIS Field calculator button greyed out?

I'm using QGIS to attempt to calculate the area enclosed by a set of points that I have capture used a GPS device. I have imported the coordinates from a CSV but when trying to open the field ...
2
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2answers
679 views

FIeld calculator gives integer not a real as requested

Two fields "population" and "F06_popula" (both integers) were used in calculating a new field pct-diff. I asked that the new field be a decimal with a width of 10 and precision of 3. The result has ...
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4answers
3k views

Basic Field Calculator help

I have no experience with Field Calculator in ArcGIS 10. I have a very simple calculation I would like to perform that I could do easily via pure SQL but just can't seem to get my head around it in ...
2
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1answer
103 views

How to return absolute values using ArcMap field calculator?

I have a field of number ranging from -50 to 50. Is there a way using the ArcMap field calculator to populate a field with all of these standardised (positive numbers) so I have a range of 0 to 50 ...
2
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1answer
2k views

How to count and record the number of entities with the same name in the field calculator?

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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4answers
94 views

Field calculator Python else statement question

The codeblock below is run on Field1 and calculates Field1 to equal Field2 if they are not equal. Else it returns Field1. My question is, does the else statement actually recalculate Field1 to equal ...
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3answers
693 views

Python and CalculateField

I am having trouble with using Python together with my gp.Calculatefield tool in my python script, and I am not sure why.. Heres the code (UPDATED) import arcgisscripting, os, sys myTempWorkspace = ...
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2answers
428 views

Looking for python/VB script to insert a new uniqe field

Is there any phyton/VB script which will add a field to shapefile which will be corresponding to first three characters from the shapefile name ? I am working in modelbuilder and arcgis 10. Thanks ...
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1answer
2k views

How to set the value of a field in all selected rows of a table using ArcGIS 10

I have an attribute table in ArcGIS (it's large - around 300,000 elements). I've selected some rows of the table using 'Select by attributes' and I want to set the value of a field for all of those ...
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1answer
110 views

Field Calculator: return two or more field value

I trying to return three field values in same If Statment and conecate them, but i Get NULL value insted of the conecated fields getClass (!InDiameter! , !OutDiameter! , !TheridDiameter!, ...
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1answer
48 views

How can I change all the entries in a field to be entirely lower case?

I have a field with a bunch of species names, but for a single species there a bunch of case combinations (e.g. Cat, CAT,cat). I want to make a new field which has all the entries in all lower case. I ...
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2answers
95 views

Field Calculator, Conditional

I am trying to assign Value from one field of my Attribute table to a new field based on the 3d field.... The Code Block I am thinking about as follows: *def conditional (!FarmCateg!): if ...
2
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1answer
273 views

How to use Field Calculator to calculate area as percentage?

I am searching for python code to use in Field Calculator to calculate area as a percentage in relation to another field? The area percentage needs be calculated based on the total area for each ...
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1answer
184 views

Calculate field result is float with Arc tool, integer with arcpy script

I am trying to calculate a field for some points within a python script using arcpy functions. (This is calculating the percentage visibility from a cumulative viewshed, if that matters.) # Process: ...
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2answers
357 views

Type mismatch error in Calculate Field tool in ArcGIS 10.1

I'm trying to run a rather lengthy model (built in ArcGIS 9.3.1) in ArcGIS 10.1 and I'm recieving an error on a Calculate Field tool. The error is - Type mismatch: 'iif'. This error is refering to ...
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2answers
514 views

Trimming Specific Text Values in QGIS Field Calculator

Sorry if this is a dumb question, but I am wondering if there is a way to copy the text from one field to a new field, but eliminate specific words. For example: **Old Field** ...
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2answers
41 views

Convert from Julian Date to Calender Date in Field Calculator

Does anyone know of a way to convert from a Julian date to a regular calender date in either QGIS or ArcGIS field calculator? Thanks...
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2answers
70 views

Conditional field calculator expression

I need to calculate the PIPEID field to equal the G_KEY_COMP field if PIPEID is null or PIPEID and G_KEY_COMP do not match. I think the first condition of the PIPEID being null is covered by the ...
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3answers
89 views

Calculate Field tool to calculate on null fields

I'm using ArcGIS 10.1. I want to use the calculate field tool in ModelBuilder on a table where if field1 is null, it should take the value of field2. If field1 has a value then it should stay as is. ...
2
votes
1answer
69 views

Remove characters inside parentheses in QGIS

I have a shapefile of the buildings on my college campus. It has a "name" field that includes the name of the building and then in parentheses the building's campus address (i.e. Health and ...
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3answers
80 views

How to write FIDs of points within each polygon to polygon field?

I have two feature classes one with points one with polygons (in ArcGis 10.2). Now, I want to write into a String Field of the polygon layer a list of all the Point-FIDs that are within each polygon ...
2
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2answers
174 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 ...
2
votes
1answer
310 views

Am I over-complicating adding and then calculating fields? Suggestions for a better way? (Python)

I'm attempting to re-position a question I asked yesterday here. I am starting to think that the way I wrote my code just isn't the best way. Am I overcomplicating things? I know for a fact that ...
2
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1answer
401 views

Field Calculate Degree Minute Second in Different Format

I have a field that is in degree minutes seconds, populated from ET Geowizards COGO Inverse tool. It populates the values as 90-12-28.15 where 90 is the degree, 12 is the minutes and 28.15 is the ...
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1answer
404 views

Field Calculator operation is not working

I've done this 100s of times and I can't understand why it won't work! I'm trying to copy the first 8 digits of from a HUC 12 (Hydrologic Unit Code) to a new field, which represents a larger ...
2
votes
1answer
511 views

Iterative position within Field Calculator/Python

I'm not great with Python or programming in general, so I'm not even sure how to ask this question. Basically what I've got is in the left column, and what I want is in the right column. UniqueID ...
2
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1answer
881 views

Summing Attributes from a Related Table?

I have a line feature class representing road segments, with each road segment having a unique ID. This feature class has an attribute of average observed daily traffic counts. I have another table ...
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1answer
538 views

Does QGIS support parsing of date strings in tables?

It is straightforward to load GPX files (GPS downloaded tracks / points) into QGIS, then save and manipulate them as shapefiles. However, the recording date (in the comment (cmt) field) of waypoints ...
2
votes
1answer
68 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
72 views

How to use Field Calculator to assign values to only Odd (or Even) page fields for Data Driven Pages?

I am creating a map book but do not want the page numbers for each map page to be on the same side (since its printed double sided), I need the page numbers to be placed on opposite sides? I am using ...
2
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1answer
51 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 ...
2
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2answers
52 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. ...
2
votes
1answer
42 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 = ...
2
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1answer
65 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
votes
2answers
493 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 ...
2
votes
1answer
104 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
101 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 ...
2
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3answers
745 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
74 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
147 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: ...
2
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1answer
87 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 ...