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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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?
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388 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
130 views

Problem in long expression in field calculator

I am trying to compute the following expression with Field calculator. The input table values are around the size of this value: 562643580,7843, and the field name (the field of destination) is: ...
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1answer
201 views

Is there a way to automatically calculate attribute values for new features?

I am creating a vector point layer which will be added to over time. I have been using the field calculator to populate fields such as X and Y coordinates. I'm wondering if there is a way to have ...
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1answer
189 views

Help with field calculator in Python script

I am getting a syntax error in my script but I know from testing it in ArcMap attribute table, the syntax is fine. Anyone have any idea why this code doesn't work? I see that a search cursor has been ...
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2answers
304 views

VBA ArcGIS 9.3 Field Calculator: 'countif' across several fields

I have an attribute table with 15 columns that contain either a '0' or a taxonomy number. I would like a summarized column that shows the number of different species. location type1 type2 type3 ...
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1answer
105 views

How to perform intersect operations in the Field Calculator in QGIS?

How to use the Intersect function? How would I specify to REPLACE layer1.field1 with layer2.field2 WHEN layer1.geometry INTERSECTS layer2.geometry Is that feasible in QGIS?
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1answer
166 views

How to correctly use LIKE in the code block of a Reclass expression in ModelBuilder Calculate Field

I have a Reclass expression that works when i am search for single instance of a data field. I also wish the Reclass to work with a SQL type LIKE selection with Wildcards. e.g. I need to reclassify ...
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299 views

Python Field Calc for Document Hyperlink

I am trying to create a script that will hyperlink to a .tiff or .pdf. These files are stored in one folder on a shared server. I want the script to look in a field: 'PLAT_IMAGE', which has the plat ...
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1answer
369 views

remove whitespace Python code results in odd character - Field Calculator

I need to remove whitespace from the end of a string in a field in ArcMap. I tried first the VBA function RTrim, but whitespace still remained. I thought maybe the whitespaces were tabs, so I tried ...
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201 views

Comparing field values to update new field using ArcGIS for Desktop?

I am currently doing an analysis in ArcMap 10 using python. I have two shape layers, one is a point layer and the other one is a line layer. The point layer have attributes for point's unique ID, as ...
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1answer
109 views

How to reach a field value of a record in field calculator in ArcGIS 10.1

I have two fields showing number of people in two age groups "young" and "old". these people also live in a cell (point) whose distance to a specific facility is calculated. then I categorized these ...
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523 views

How to calculate field as cursor name?

First time dealing with cursor. I have lines intersecting polygons, I want to get a table with all attributes of the lines, add a field and calculate the field as the name of the polygon. I was able ...
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1answer
94 views

How to import text only out of a string field to a new field

I want to import data out of a string field in my shapefile to a new field for labeling. The string field contains river names and codes and I just want to display the text i.e river names
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1answer
2k views

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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18 views

Incorrect Acreage QGIS 2.6.0

I have six polygons, all of (fairly) similar size. The first one is 8 acres, the others are obviously wrong with 120,000 acres, and 106,000 acres and so on. I am calculating with the field calculator, ...
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27 views

Systematic inaccuracy in QGIS shape area

I’m trying to find out why I get different area figure in QGIS than in AutoCAD when I’m using the same shape file? What I did is I drew a shape in AutoCAD, imported it in QGIS and used the field ...
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39 views

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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1answer
28 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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41 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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23 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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38 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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59 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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37 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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1answer
58 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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79 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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1answer
41 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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32 views

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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1answer
75 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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68 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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192 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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0answers
229 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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1answer
73 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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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
470 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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1answer
325 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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1answer
202 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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36 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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1answer
76 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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210 views

Select Expression and Field Calculator in ONE STEP with QGIS

I have an Open Street Map Shapefile and i want to use Field Calculator to add information to a field called a800900 according to the field TYPE of street, by different area (field called ID_2). The ...
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92 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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124 views

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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1k 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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1answer
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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1answer
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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251 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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129 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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2answers
428 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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2answers
382 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?