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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Do QGIS Field Calculator xat(n) and yat(n) functions work in version 1.7.x?

I'm trying to use the xat(n) and yat(n) in the Field Calculator but can't get them to work. Does anybody have an example how to use them? I need the start and end coordinates for line segments, does ...
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ArcGIS Calculate Fields gives Warning 000405 No records within table?

Situation: I have feature layer sitting outside processing extent in Environment settings. If I open layer's table and use field calculator - Calculate Geometry on some numeric field: it works ...
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20 views

How to fill column with several conditions using QGIS field calculator?

I know the synthax in order to fill one field with only one condition (field calculator): case When "attribut" = 'value' then value End But how to do populate automatically one field with ...
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35 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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20 views

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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35 views

Passing Value for Dictionary Look Up in Field Calculator fails [closed]

I've a field calculator that I am trying to use that uses a csv file to look up appropriate value based on key that is passed provided to the function. As provided below, the only values calculated ...
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42 views

Field Calculator stopped working

The field calculator seems to have stopped working for one of my attribute tables (it works fine on others). No matter what I get it to express (I've tried simply 2*2, just as a test) it just produces ...
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33 views

Trying to export stacked text to CAD using ArcGIS 10.2

I've been experiencing some unwanted results when trying to export stacked text to CAD using ArcGIS 10.2 for desktop. With the Export to CAD tool I can easily export polygons. However, I'm also trying ...
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56 views

Use value of Field in Calculation in Modelbilder

In Modelbuilder I have set up a model, where in one step I do a "Calculate Field" like "round((!OID!-1- %MyField% /15)/452,1)+1" . For the calculation i use the value of %MyField%, which actually is ...
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60 views

QGIS field calculator expression: selecting min/max values within field groups

I am new to using QGIS (previously used Arc) and trying to get my head round the expressions and Python. I have series of polylines representing routes and require the linear distance from the ...
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39 views

Categorizing GPS data based on cumulative time using ArcGIS Desktop?

I have GPS data which includes “Lon”, “Lat”, and cumulative Time from 0 (sec) as fields. I want to add an integer variable new field, “Trip,” which starts from zero, and is incremented by one after ...
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Field Calculator QGIS: CASE WHEN [duplicate]

at first, sorry for my English. I'm using Google translator. I have a .shp file with attribute table. Like this... -- A -- -- B -- -- C -- QString Double Double Data ...
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73 views

Concatenate fields value excluding empty values

I need to concatenate the value of two fields excluding empty values, using Field calculator. The fields are: AREA_HI and AREA_LO I have tried using a Python script but ArcGIS returns an error ...
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63 views

Geometric functions in field calculator in QGIS

I had a look in the manual of QGIS and I also browsed the Internet to find some useful information about the geometric functions of the field calculator. I've found this post but I'm still confused. ...
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161 views

Cumulative field calculation using Python in ArcGIS for Desktop?

I am using the following Python code to sum cumulatively but I need the summation to take place while the other field is equal to 1 and then again start the summation when it's equal to 2. I need the ...
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203 views

Cause of Field Calculator UnicodeEncodeError: 'ascii' codec can't encode character u'\xf6' in position 5: ordinal not in range(128)? [closed]

def Befahrung(value1,value2): if value1 is ' ': return ' ' else: return "G:\\Example\\" + str(value1) + "\\File_" + str(value2) + ".pdf" I try to create a field with a hyperlink. It works ...
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69 views

Calculating average of 3 fields where nulls are present

I have created a new field to calculate the average of 3 other fields in a table where nulls are present. Using python as the parser(with no code block) I used this: (!Slope_PCT! or 0 + !Flood_PCT! ...
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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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434 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 ...
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315 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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199 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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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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372 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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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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Import csv file and use “toggle editing” and “field calculator” without Saving it as a Shapefile.

I am importing a .csv file in QGIS and I have also made the *.csvt file where I have specified my data types. I still cannot use "Toggle editing" and "field calculator".Whether I must save it as a ...
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986 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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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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247 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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125 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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368 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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371 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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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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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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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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103 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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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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155 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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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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56 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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67 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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4answers
732 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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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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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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if/then with VBScript in ArcGIS Field Calculator giving Error 000539: SyntaxError: invalid syntax?

What is wrong with this VBscript in the field calculator? ColumnC= if [ColumnB] > 0 then [ColumnC] = [ColumnA] / [ColumnB] endif Each time I receive this syntax error message: Error ...
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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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62 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 ...