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.

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Calculating Percentiles in ArcMap?

I have a large polygon dataset (26,000) records with numerous attributes columns. I wish to calculate the percentile rank of each attribute. Say I have population_density in an attribute, is there a ...
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191 views

How to create sequential field based on sorted data? (or extract pop-up data?)

I downloaded a kmz field and converted it to a GDB fc on arcmap. However, the field I need to label the layer by is stored in the pop-up html field... It looks like this: <html ...
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1answer
134 views

How to calculate unique IDs starting from highest current ID

I have been using a python script in field calculator in ArcGIS 10.2 to add unique IDs automatically, however there are two things I would like to improve this process: Each ID also has letters at ...
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34 views

Concatenate Multiple String Fields and Convert to Date field using ArcGIS Field Calculator?

I'm Working in Model builder using the calculate value tool. I have three columns - SignatureDay, SignatureMonth, SignatureYear - All three are string data types and all consist of just numbers for ...
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3answers
725 views

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
367 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 ...
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1answer
120 views

How to calculate the intersected area from a layer with overlapping buffers in qgis

I need to calculate the area of landusetypes in 50m around various dots (all in one shapfile). My problem is, the buffers around the dots are overlapping each over in some places. I tried to ...
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2answers
97 views

Using Python For a Field Calc

In AcrMap 10.2 I'm trying to add a field and run this script in Field Calc: !shape.isMultipart! to see if I have any multipart lines. I keep getting geoprocessing failures. I am clicking the ...
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52 views

How to perform If Statement in Field Calculator of ArcGIS for Desktop? (Python or VB)

I've one field "MAXSPEED". I want a Field Calculation that will calculate an additional field ("noise"): If MAXSPEED > 40 then the term: (73.5 + Log ( 25 ) * ( [MAXSPEED] / 50)) should be used to ...
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3answers
611 views

Random value calculation in QGIS

Is there a way to do a random value calculation within a range in QGIS? I have been able to do this within ArcMap Field Calculator with the following code: Dim max, min max=20 min=5 ...
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2answers
17 views

QGIS upper round in field calculator

I need to to in the field calculator the following calc: toint(Field1 / 25.0) but i need to round the result to no decimal places but upwards. Exmaples: If 17/25 result should 1. If 25/25 result ...
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21 views

Assigning score to raster based on cell overlap with other raster and field value

I have a set of rasters that I've assigned scores to individually (scored based predominantly on values of other fields). The scoring scale is the same for all rasters, but the factors that determine ...
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3answers
26 views

VB Script field calculator - error with conditional statements

I have limited VB Script experience, but have been working on the script below and keep getting errors, the most common being "expected identifier". Can someone tell me what I'm missing here? Dim ...
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1answer
96 views

Can you use wildcards for column headers in Field Calculator?

I know you can use wildcards for fields like so (in the Field Calculator): case when "column" ILIKE '%example%' then 1 else 0 end Can you do something similar for the column headers themselves? I ...
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4answers
36 views

Auto populate field with text using field calculator if/then

I've extracted values from a raster to a point file, but now I need a field with the text information from the raster attribute table that corresponds with the value. I've been trying to use the field ...
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1answer
40 views

How can I refer to two tables in ArcPy's CalculateField_management?

I tried to refer to the different table's fields just like I saw in How to Calculate Field in joined table using ArcPy? but it doesn't work. There are two tables in my example. I have created table ...
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22 views

How to use calculatefield_management with ArcPy and joined second table? [duplicate]

How can I use calculatefield_management with ArcPy if I have a joined second table? I want to go through the attached table's field and I want to get records where the certain fields is. How can I ...
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2answers
33 views

What fields can the CalculateField_management expression parameter contain?

What fields can the CalculateField_management expression parameter contain? I mean the parameters can be the fields what are in the output table, or can they be a field of another table too? There ...
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1answer
940 views

How to Calculate Field in joined table using ArcPy?

I have to calculate a field based on another field in a joined table, but an error occurs: "Parameters are not valid. ERROR 000728: Field !Table_A.field_A! does not exist within table" My code: ...
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1answer
717 views

Why is using two imbricate UpdateCursor not working?

I hope my question is not redundant. I wrote a script to Update a table using two imbricate cursors. The goal was: to read a records, update some of its values Make a selection based on this ...
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5answers
145 views

Field Calculator expression to replace string only if it occurs

I have two fields (STREET1 & AKA_STREET_TEST1). I'm having a problem creating a simple IF THEN Python statement in the Field Calculator box. I've been searching the threads for a similar ...
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2answers
36 views

Field calculator to copy numeric values from other fields

FieldA contains text: both numeric(123) and alpha-numeric(123a, 2-3, 3/2, '). FieldB is longstring. I want to use field calculator and codeblock on FieldB to bring from Field A only the numeric ...
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1answer
57 views

Join and Field Calculator

I made a Join between a shape and a dbf, and now I want to calculate some data from the table that came as a result from that Join. Everytime I try to run the Field Calculator it says there's an ...
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QGIS (2.0.1): Field calculator for length not working - values way too high

Same problem as another thread: Field Calculator returning incorrect length and area values Trying to calculate length of a line shapefile, and field calculator is returning values that are way too ...
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2answers
39 views

Large dataset, how to copy values between fields

I'm in this position: i have a feature class containing about 6 million entries. I made a summarize and and generated a new table. I joined the two tables and now I need to copy the values from the ...
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1answer
304 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. ...
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384 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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22 views

How to use random number generator to select by attributes in ArcMap? [duplicate]

I am not familiar in using Python and random number generator. I was wondering how to select 250 rows/values from a column named "JUROL". Every value in that column is different and the column ...
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25 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 ...
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1answer
173 views

Auto increment a new column using Model Builder Field Calculator in QGIS?

I am making a model which requires creating a grid and clipping various layers to it. Using the Create grid function does not provide an ID column, instead it creates 2 columns: "longitude" and ...
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1answer
418 views

Adding count of features in categories to legend using ArcGIS for Desktop?

I am using ArcGIS 10.1 for Desktop and I would like to know How to add the Count (which is visible on the Symbology tab of the Layer Properties dialog) to the legend?
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1answer
222 views

Why is field calculator returning NULL for $x and $y in line and polygon layers?

I am trying to include XY coordinates in the attribute tables of several of my vector files; they are line and polygon files. I have tried two methods; first I used $x and $y in the field calculator ...
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2answers
590 views

How to use the replace string function in Field Calculator?

Within an attribute table I'm trying to replace one string with another using the 'replace' function . As an example, there are a number of features whose field 'NAME' contain the string '(B)' and ...
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2answers
55 views

Editing tables in ArcGIS for Desktop with Python Parser of Field Calculator?

so I'm trying to edit a table so that the name column will not contain spaces. I just don't know how to write the Python script that should go with it. This is what I have for the Python script ...
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1answer
92 views

Calculate average value for each row

The picture is an example, but the method would be the same at mine bigger dataset. So i have some parcels with each a ID value and some fields. such as field 1, field 2, field 3, fieldd 4,... with ...
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2answers
164 views

Problem using field calculator to add numbers in new field with preceding zeros

I wish to add a field in an attribute table that should work as a georeferencing key. It needs to take into consideration values from a series of fields. The last field is a housenumber and it ...
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1answer
45 views

python expression convert field to string and format with leading zeroes

I would like to create an expression using the field calculator in ArcMap to be able to convert an Int field to a string and add leading zeroes. I am able to do it in a python window with an example ...
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2answers
942 views

How to get latitude /longitude in Degree Minute Second (DMS) using QGIS field calculator?

I have come up with the following expression to convert 5.1234 to 5° 7`24.24" toint ($x) || '° ' || toint((($x) - toint ($x)) * 60) ||'`' || substr( (tostring(((($x) - toint ($x)) * 60) - ...
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1k 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 ...
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1answer
45 views

Use field calculator to reclassify values from three different fields to populate a new field AND determine overlap with different raster

I want to reclassify values of 3 different fields AND determine if one of those fields is located inside a different polygon to populate the values of my new field. Everything is raster. I created a ...
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2answers
79 views

Assign field values (double) based on values of other field (string) using field calculator

I want to assign numbers to a field, WScore (double), based on field values of Soils (string). They are in the same table of a raster. I'm not trying to add text to a double. What I want to do is ...
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1answer
52 views

Basic Python Reclass question in Field Calculator

I'm trying to reclass values in field calculator using Python. I want any value >= '5' to remain the same (return same value). Anything else to be = '0'. Yes, DIST_EDGE are numbers. I'm getting an ...
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2answers
59 views

select parcels in polygons and add fiels depending on the polygons

I have a lot of feature classes (results of service area with different polygons (0 to 10/ 10 to 20/ 20 to 40 and 40 to 60) (figure 1) Also i have a shapefile with a lot of parcels (figure 2) ...
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3answers
998 views

How to insert a quotation mark through the Field Calculator of attribute table of a Shapefile?

I have a shapefile of polylines with information of diameter. But the problem is that i didn't enter the inch sign(") with the values of diameter. What would be the solution that qutation mark would ...
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1answer
353 views

Calculating Stream Length-gradient Index (Hack Index) with the field calculator

I'm trying to calculate the Stream Length-Gradient Index of a stream (example data below). Just started to get into python, but am struggling with a solution to this problem. I have 42 streams to run ...
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1answer
1k 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 ...
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99 views

Calculate Fields from 3 different fields using ArcGIS for Desktop?

I'm using a shapefile of different vegetation and land cover types and I want to generalize to a simpler classification (ie. I only need to differenciate between young and old forest and open land, ...
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1answer
68 views

Extracting data from Address field using ArcGIS for Desktop?

I am fairly new to using python in field calculator and could use some help. I want to populate SitusRdType with RD or AVE or LN or ST or DR depending on the road type. I also want to just have the ...
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1answer
143 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 ...
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1answer
30 views

Add a certain number of days for a date field

I have one field for a permit decision date, and then I have another field for 180 days from that permit date. The permit date field has data entered, but the 180 day field I would like to calculate ...