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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3
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1answer
275 views

Using Python in Field Calculator to compare two fields

I'm trying to use field calculator to compare two fields in a table of tax parcel data, Land Value (LAND_VAL) and Improvement Value (IMPRVT_VAL). My goal is to determine (1) Parcels with land value ...
2
votes
4answers
159 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 ...
1
vote
0answers
21 views

Can a joined-layer have its attribute changed depending on what layers are selected/deselected?

Using QGIS, I have a polygon-grid layer which covers everything, Layer_All joined with 2 other grid layers: Layer_1 and Layer_2, both of which intersect at various points. I would like Layer_All to ...
3
votes
1answer
78 views

How do I add a field to a table using the QGIS graphic modeler?

I was wondering if anyone could help as I'm struggling to get anything out of the QGIS graphic modeler. For info I have no programming skills whatsoever. I need to be able to add a new field to an ...
2
votes
1answer
79 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 ...
1
vote
1answer
286 views

Null value error with Python in field calculator

I'm trying to calculate the angle between two line segments in ArcMap 10.0. I have a point shapefile, so I'm using the xy coordinates of 3 successive points to calculate the angle. I'm trying to use ...
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
90 views

Python field calc syntax error

The screenshot shows a calculate field tool in modelbuilder. The error I'm getting is invalid syntax line 1. I can't see any issues w/the syntax so I'm hoping someone out there can help. It ...
1
vote
1answer
72 views

Python in ArcGIS, CalculateField_management, updating with single value

I have a float field which I want to simply update all values with 1. I can easily do this within the field calculator but I have started using python today, what is the syntax to simply update a ...
2
votes
1answer
49 views

Expression to create and populate column based on filtered fields

I wanted to create a column and populate it with data based on data from other fields. If column_1 contains fields which has similar string (eg. field_1 = "Country: UK", field_2 = "Country: US", ...
1
vote
1answer
65 views

Create and immediately update field using Field Calculator

You can create fields and once created, populate them with data using the Field Calculator. But can you do both at the same time using an expression? Or must you do it in 2 steps?
-1
votes
1answer
112 views

IF-Statement in Field Calculator [closed]

I want to use an IF/ELSE-Statement to define a field in the attribute table of my raster. Therefore I have a field "VALUE". The condition should be: If "VALUE" < 4 ...then use die field "A".....if ...
3
votes
0answers
66 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 ...
1
vote
1answer
27 views

Does ArcGIS Desktop have conditional function useable in field calculations?

Does ArcGIS / ArcView 10 have a conditional function, e.g. ifx(test,if_T,if_F), that could be in-lined in field calculations?
2
votes
2answers
118 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 ...
-1
votes
1answer
73 views

Why does dividing two decimal field values using Field Calculator return/write Integer? [duplicate]

I have fields in my datasets such as HR60, HR70, HR80, HR90 When I tried to use field calculator using the following [HR70]/[HR60], all I got was 1, 2, 3, 4 as my values. Last time I checked ...
2
votes
1answer
135 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!, ...
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 ...
3
votes
2answers
358 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?
5
votes
0answers
207 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, ...
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 ...
0
votes
2answers
302 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 ...
6
votes
3answers
2k views

How to replace non-English characters in attribute tables using Python?

I have a few shapefiles where some of the attributes contain the non-English characters ÅÄÖ. Since some queries doesn't work with these characters (specifically ChangeDetector), I tried to change them ...
8
votes
5answers
324 views

Print out the properties of the attribute table in qgis?

I have to merge a lot of shapefiles into one great shapefile. So I want to compare the properties of the attribute tables to see if there are differences between the tableproperties of each shape ...
1
vote
2answers
45 views

How can I populate a field of the polylines to indicate if they intersect?

I have two feature classes, one ploylines, one a buffer. How can I populate a field of the polylines to indicate if they intersect?
1
vote
0answers
34 views

How to replace accented strings in attribute tables using Python or VBA ArcGIS 10.2 [duplicate]

I need to replace accented words, into the Field Calculator, to the same non-accented ones. For example: María ---> Maria Need some help with this VB Code: Dim data as integer Dim contador Dim ...
1
vote
2answers
402 views

area values determined with field calculator become null when saving

using field calculator in Qgis 1.8.0 to get the area, it shows just right at first but when I save it, the values become Null. help please
2
votes
2answers
116 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
2answers
151 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 ...
5
votes
3answers
1k views

calculating a field in which null values may be present

I would like 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. For example, ...
2
votes
1answer
72 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 = ...
3
votes
3answers
96 views

Field calculator problem

I have an issue withe the field calculator. It is impossible for me to multiplicate 2 columns (area * KZ). The result is always "0". I used the formula area * KZ....is this the right formula? LINK to ...
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
0answers
154 views

ArcGIS Python Field Calculation

Ok so i've got a problem with the field calculator in ArcGIS: I'm already pretty far with it since i got some help :P but it still doesnt work. What i've got: -A complete table of several states of ...
2
votes
1answer
291 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 ...
1
vote
2answers
121 views

Calculate field based on most frequently occuring text/value in other fields in attribute table (ArcGIS)

I was wondering if anyone knows if it is possible to calculate a field based on the most frequently occurring value in other fields. What I have is 5 fields with crop information over 5 consecutive ...
1
vote
1answer
1k views

Delete first two letters from a string field

I'm looking for a field calculator python statement to delete only the first two letters of string entries. For Ex: !Name!.strip([0:2]) I know this syntax is incorrect. Thanks a lot
2
votes
1answer
56 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 ...
2
votes
3answers
196 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. ...
0
votes
2answers
288 views

Model Builder Error populating attributes with Calculate Field

I would like to run a model that iterates over all feature classes in a feature dataset and uses the feature class name to populate an attribute field (see model below). However, when running the ...
0
votes
0answers
71 views

Field Calculator: Error message

Field Calculator: using the x- or yat or (0 "or-1" ) expression, I keep receiving an error: An error occurred while evaluating the calculation string: Index is out of range. I have shut down and ...
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 ...
3
votes
3answers
455 views

How to create button that calculates acres on selected polygon features?

I'm looking to create a simple button that calculates acres on selected polygons and can't quite find what I'm looking for. I read through this thread: automating a python script..., but found it ...
3
votes
1answer
67 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 ...
2
votes
0answers
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 ...
1
vote
2answers
79 views

How can I do more flexible matching in conditional expressions than provided by LIKE?

With LIKE '%' works but I have had no luck with character ranges, i.e. [0-9] to match a digit. Oh for a regular expression ;)
1
vote
2answers
98 views

Iterate through each county in a shapefile, select the county and make a second selection by location - modelbuilder

The goal of my project is to create a table with two fields. The first field showing a county name and the second field listing every county that touches the boarder of the county listed in the first ...
3
votes
2answers
118 views

ArcGIS 10 Field Calculator [closed]

I'm new to GIS in general and field calculator in particular. I have a basic attribute table with three columns. I'd like to assign values to column C based on what is in column A. If Column A = 8 ...
3
votes
2answers
94 views

How To Determine Percent of Matched Data?

In my attribute table, I have 2 columns with qualitative (categorical) data. Both of them are from different sources so I am trying to find the percent of matched data from these 2 columns. I created ...
3
votes
1answer
99 views

How to find lowest value that is not null using Python in ArcGIS for Desktop?

I have four fields in my table, (A,B,C,D). The field type is double with some fields being NULL. I used min(A,B,C,D) to return the smallest value and it works well if there are no NULL value in any of ...