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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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 ...
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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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35 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 ...
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354 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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72 views

Mismatch in area calculation using Field Calculator vs Group Stats in QGIS 2.0

I have two polygon files (A being my area of interest and B being a categorised land cover layer). Both layers were in the same projection (projected and not geographic). Using QGIS 2.0, I used the ...
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89 views

VB Script can't run in Field Calculator

I wrote a simple script in VB. But it failed to run in field calculator. I can't figure out what is wrong with it. Below is a screenshot. Thanks for your help.
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945 views

Using multiple fields for a Reclass calculation in ArcGIS Field Calculator [closed]

I am trying to create a dummy variable from an existing dataset using ArcGIS's Field Calculator tool with a Python script. My conditions require the use of multiple fields to determine the output ...
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63 views

How to measure area of polygons generated from gps data in qgis? [duplicate]

Somebody classified my question as a duplicate. But applying the answer doesn't work for me. Here is what I did: - I made sure that my layer is in a projected coordinate system (UTM30N, WGS84) - I ...
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1k views

ArcGis File Geodatabase with Null values (Field Calculator)

I want to use the field calculator to get the sum of a couple of columns. The problem is that some of them has Null Values. I am not able to find a solution. I tried this Python functions: stack( ...
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1k views

How to use field calculator for area calculations in QGis? [duplicate]

Possible Duplicate: Calculate area between contour lines on a DEM with Qgis 1.8.0-Lisboa Based on a DEM of a whole country I have reclassified altitudinal bands with steps of 100 metres ...
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244 views

How to calculate column average in Arcmap using VBA [closed]

I'm really new in gis and programming... So could anyone write VBA code for counting average. For example I have 3 columns which are named as JAN, FEB, MART...Each of them have 50 values in column. ...
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117 views

How to compute percent of a field

I have a layer with a column conaining population values. I want to write an expression to compute in a new field the percentage of population each polygon has in relation to the total population. I ...
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298 views

Using python elif syntax in Field Calculator to reclassify a range of values from a different field and populate a new field

I'm trying to use the Field Calculator with a python elif statement to reclassify values from a different field and populate a new field, and while I'm not getting an error message of any kind, I'm ...
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353 views

How to use centroid option in Field Calculator in QGis

I want to use Centroid option in field calculator in QGis .How to access it?
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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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718 views

ERROR 000989: Python syntax error: Parsing error SyntaxError: invalid syntax (line 2)

I have a Field Calculator I am using with Python and I keep getting the above error. Below is the screenshot of my Field Calculator I am using. What am I doing wrong here?
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62 views

Populate a field from another field with a conditional

I am working in SDE geodatabase where I have a feature class 'Mange_Waste' and "Q1", "Q2" are two fields. I wanted to use python script for populating "Q2" from "Q1" with a condition. Like, if the ...
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100 views

Use Python lists in Field Calculator?

I couldn't find this question, although I am sure it has been asked. How could I use a python list to condense this script? This code block currently works, but is clearly not very efficient. def ...
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3answers
85 views

Python QC field calculator

I am new to Python and am trying to run a simple QA/QC on a particular set of fields. I basically want to verify that fields x and y add up to z, I may have to incorporate rounding since a small ...
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150 views

Error when calculate field using VBscript or Python (slice a field)

I have an expression in VBscript that works well for labeling: Function FindLabel (field) if (INT(RIGHT(field, 2)) <> 1) then FindLabel = INT(MID(field, 8, 3)) &"-"& ...
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105 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 ...
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3k views

Changing null value to specific numbers in ArcGIS for Desktop? [closed]

I have a Excel file showing annual precipitation and I add it on arcmap. When I tried to check it's attribute table the field calculator is passive. I want to change all the Null value to specific ...
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54 views

Field calculator (using ATAN)

How do I input the arc tan in the field calculator given the values of the fields to get the desired answer, I compare the answer of the manually computed arc tan value and the Atan Spatial Analyst ...
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53 views

What is expression for finding perimeter in ArcPy and Field Calculator?

What is the correct format for finding perimeter as an expression for arcpy. I was able to use expression !shape.Area! to find the area of my polygon. However when I use the expression ...
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569 views

Calculating acreage using ArcGIS Field Calculator?

What is the expression to calculate an acreage in USA ? I am aware that there is a geometry calculate but when you convert raster to polygon it doesn't do it's job and I have to use the field ...
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51 views

If clause within if clause VBA Arcgis10

I'm using ArcGIS10. I do not know what's wrong with this VBA code in the Field Calculator: *All the fields are String type If [StartY] < [EndY] Then If [DOT_OSM] ="1" Then Output = "F" ...
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130 views

Parsing field in field calculator using Python

I have field1 which has a values of "A_B" (example). I created two fields out of this, values to the left of the underscore go in fielda and to the right of the underscore go in fieldb. I used the ...
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37 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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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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66 views

Using Field Calculator to fill out a list of unit numbers

I am adding address points for individual units in trailer/RV parks and I would like to be able to use the Field Calculator to assign the unit numbers. Is it possible to tell the Field Calculator a ...
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95 views

Field Calculator If/Then in ArcGis 10.1

I've been looking through these threads, i found something similar and thought it could be the answer, but it doen't seem to work for me... I could do this the slow way with Select By Attributes, but ...
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Debugging CalculateField_management ERROR 000623: Invalid value type for parameter field?

I am trying to select records in my table that have certain words in the "Name" field and then code them as 0 (not pharmacy) or 1 (pharmacy) This is just a test searching for two words to select ...
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57 views

Field calculator fails when computing First X coordinate in ArcGIS10

I have this line in python to compute First X coordinates into the Field Calculator from each polyline: !Shape!.firstPoint.X Then, when I inspected the attributes I see this rare thing: You may ...
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32 views

How to implement a Gaussian function in field calculator?

Are there any build-in functions like Gaussian or Epanechnikov functions in field calculator? Or I have to write that by myself?
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86 views

ArcMap Change Values Greater than Standard Deviation of Mean to Zero

I have a feature class with greater than 1000 features and I would like to change all values greater than 2 Standard Deviations to a Zero. Seems like I could possibly use Field Calculator for ...
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57 views

trying to add content to the middle of a string

I am trying to add content to the middle of a string by using MyStr = Mid([MyField], 1, 1) and I get an error. I've tried MyStr = Mid([_smallx], 63, 6) and MyStr = Mid(["_smallx"], 63, 6) The ...
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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 ...
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836 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 ...
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825 views

How to use VBA in the field calculator, to copy the last 7 characters to a new field?

Im using ArcMap 9.3. Im looking for a VBA code to use in the field calculator to make a new field of the last 7 digits of a "pin" field. For example. my pin is 00-00-999-999 and i want it to ...
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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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34 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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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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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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1answer
35 views

How to populate new field according to string content of another field using VB script?

I want to populate a new field called Letting according to the string value found in another field. If 'ASP' or 'Q' is in field ExternalRE then I want 1 in Letting, everything else to be 0. Here is ...
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73 views

Is it possible to have auto-updating area fields?

I'm using QGIS 2.4.0 and I've noticed some problems with the derived area and the $area field. Firstly, I have a polygon which is a filled ring, inside another polygon. The derived area, and therefore ...
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84 views

Calculate Field based on two fields using python

I'm trying to calculate new values for a field based on two other fields. In VB I don't have any problem, but I need to use python to publish my gp service.
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62 views

How to flip, or invert attribute tables with respect to row ID arcgis

I need to invert the fields of an attribute table relative to the row ID field. As a very simple example of what I need; if the row IDs of 1, 2, and 3 corresponded to identical values in another ...
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64 views

Calculating Area of Raster Classes

I have a raster in a GRID format that was created by Image Classification. The GRID is projected in StatePlane meters, but I would like the area in square feet. I'm assuming I will need to use the ...
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34 views

Filling Field2 to icorresponding values in Field1 of shapefile using Field Calculator of ArcGIS for Desktop?

I have to give explanation in a new field of the existing field which contains abbreviation. Example: Field "Geology" has values Q, Qs,N....(abbreviation), I have to give explanation of those in a ...
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256 views

Using Field Calculator to Add a Set Amount of Time to Date Field

I wish to georeference several photos to a track created using a Garmin Oregon 450t, but the time recorded in the photos and the time recorded in the .GPX are not the same. The format for the date ...