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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53 views

Add value to entire column in attributes

Is there a way to add a value to the entire column? I don't think i can use raster calculator because it's a text i want to add, the letter "B". Here is a picture. This is what happends when i use ...
3
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2answers
40 views

Using Field Calculator vb to check for name with /n in the string?

I am calculating values for a field (Score) based upon the names from another field (Modified). One name is "blaugh\nblaugh". Field Calculator keeps treating the name as having a new line command. I ...
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1answer
28 views

calculating sq ft of an picture image with only a scale bar as reference

I have an architectural image of a building. However, I had to change the blueprint and extend the walls out further increasing the total sq.ft., and simply for the means of drawing out the new ...
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1answer
44 views

failed to Writing conditional (if/then) statements into Field Calculator of ArcGIS for Desktop using Python parser?

I wrote this following several examples but it is still wrong. I need to populate a new field based on 5 ranges of values. def marks(Wards for try.JHRatio ): if (Wards for try.JHRatio <= ...
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0answers
50 views

Calculate z score into new field in ModelBuilder? [closed]

I'm trying to calculate z scores for a given column. I am working with a shapefile, that contains fields like percent poverty, percent tree canopy and temperature. My ultimate goal is to add new ...
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2answers
114 views

“CountIf” or alternative function in ArcMap field calculator?

Within ArcMap 10.3 field calculator, I am looking to count the number of features in a column that match the current value, and output that count. Ideally, the output would look like this: Number ...
0
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1answer
87 views

How calculate sequential values based on group field?

In field calculator i calculate sequential values in field [ORDER_ID] What need change in script to calculate sequential values based on group field [GROUP_ID]. I select values manually and use ...
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0answers
60 views

Replacing Null values with field calculator

My goal is to use the field calculator to replace null values. I am trying to replace nulls in the ToDate_Time with the FmDate_Time. When I run the code below the results window says that it worked ...
2
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3answers
237 views

How to get around “The field is not nullable” error?

I have a shapefile of lines. I want the angle of every line calculated in a field. I am using the script below in arcmap, but when it encounters a line that is horizontal, it stops calculating any ...
2
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1answer
44 views

Loading Features prompt in QGIS?

I'm currently working on a dataset with 3.8m records. I have a very simple expression to update a field that I want to execute using the Field Calculator, while having the Attribute Table open. Do I ...
2
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2answers
91 views

Formatting SQL expression for calculate field (management) tool?

I am trying to take the population census tract and calculate the percentage of population by each census tract in the field (Populati_2). To do this I'm creating a new field with the total sum of the ...
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3answers
136 views

Using Field Calculator to compare two fields in att table and returning if equal or not in ArcGIS for Desktop?

Using 10.2.2 I am attempting to compare two fields in an attribute table using the Field Calculator. I'd like to return a value of '0' if they are equal and a value of '1' if they are not equal. ...
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1answer
71 views

Calculate percentages with field calculator in arcgis?

I am trying to calculate the percentage of each the area of each polygon in the selected area. I tried using ( math.fsum(!shape.area!) / !PolygonArea! )*100 and other codes but I cannot make it work. ...
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2answers
34 views

update cursor based on location

I'm working on a python script for ArcGIS 10.2/10.3. What I want is to automatically fill in a field of a point layer based on the location of that point in relation to a polygon layer. Say I have a ...
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2answers
129 views

Update multiple fields/columns in QGIS

I need to update fields in attribute table of a vector using QGIS. I use field calculator for each field, but i have too many fields (and too many vectors also) and i need to program the task. The ...
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0answers
11 views

How to calculate area percentage from polygons from one shapefile within another? [duplicate]

I'm working on a project where I have to create python code that takes land-use data and adds a percentage field for each land-use category in a Census Tract shapefile. I've been trying to work with ...
0
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1answer
44 views

Creating IDs for multiple features in Python Parser of ArcGIS Field Calculator?

Does anyone know how to create ID numbers for multiple features using python? For example; (IDs being the object ID, Name and object ID being two different fields) Names //// IDs Street 01 River ...
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1answer
22 views

Clearing Calculate Value before Model Run in ArcGIS ModelBuilder?

I am using ArcGIS 10.2 for Desktop. I have a model which contains several branches, which branch should run is based on the results of an earlier stage in the model. If the first stage of the model ...
2
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1answer
103 views

Populating attribute table string field with values from long field using vbScript in ArcGIS Field Calculator?

I want to calculate the field "area_type" with text depending on numbers from the "Value" field. I have tried with the following VB-script in "Field Calculator" but am getting this error message: ...
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2answers
75 views

Using nested If statement in Python parser of ArcGIS Field Calculator?

I'm trying to use field calculator to assign values to a new field I created. I wan't to assign the value from the first field unless that field is empty, if it is empty use field 2, if that is empty ...
1
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1answer
37 views

QGIS field-calculator: set attributes to 1 if country name is in a list of values

In a country table, I create a region field, ECOWAS, with 1 if the country belongs to the regions 'ECOWAS', 0 else. Country names are in the field "sovereignt". How can I build a field-calculator ...
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2answers
57 views

Iterating field calculations in arcpy

I was successful in adding multiple fields but had trouble running multiple field calculations in a loop. Now what I want is loop through these existing fields listed in mult_fields variable and fill ...
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1answer
40 views

Field calculations and existing domains

I have feature layer which needs to be updated with new attribute information. The text field I need to populate already has an established coded domain. I need to update hundreds of records and don't ...
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3answers
110 views

Python code help for ArcGIS Field Calculator tool (Model Builder)

Is there any python code that: 1st, sort a column (example name by alphabet) 2nd, grab the first cell of sorted column and assigned it to a variable like A=.. I need all of this to be done in field ...
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2answers
109 views

Replicating Summary Statistics tool with case field using own calculation within ModelBuilder?

I thought this would be a simple problem to solve, by my googling hasn't provided the answers so far. I have created a near table (Using the 'Generate Near Table' in Arc) comparing two sets of ...
2
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2answers
59 views

Sequential attribute field calculations with null values using Arcpy

I have a series of x,y co-ordinates converted from a .ply file. I was able to extract the file into a suitable x,y format for arcmap, the issue I have is that they are co-ordinate points representing ...
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0answers
58 views

Converting UTM to Lat Long inside a Game Engine(Untiy 3d)

This is my first post on Stack Exchange. I have exhausted my research through the game engine forums, so I am trying this forum since you guys seem to be the experts. I have an external device that ...
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1answer
52 views

How do I round the coordinates of a point before insert into attribute table in ArcGIS?

Until now I doing the following steps to get rounded coordinates: create a new x and y column in the attribute table use Calculate Geometry round the column value with the Field Calculator using VBS ...
2
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1answer
92 views

Running ArcGIS field calculation using Python with algebraic expression using other field values as variables?

I'm trying to run a field calculation using multiple fields in a table as well as independent numeric values with python code in the field calculator window. I've included the first 7 lines of the ...
0
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1answer
64 views

What expression needed for universal naming of parts polygon feature class?

For example, i have n count of polygons and little parts of it. I want in field [Name] get string: "PNum1(1)". where "1" - number of main polygon [Num], "(1)" - number of part of main polygon ...
3
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1answer
270 views

Extract string between special characters - and / into a new field ArcGIS Field Calculator

Can I create a field calc expression in ArcGIS 10.3 to print a selection between special characters? I would like to extract a selection of string from field [FolderPath] to a new field [Name]. The ...
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1answer
44 views

Referencing external CSV file within ArcMap field calculator using python codeblock?

I would like to know if there is a way to incorporate an external csv file into a custom made python script in ArcMap field calculator. I am inputting fields from the current layer, but need to access ...
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1answer
65 views

Adding Rasters with multiple Field Values using Map Algebra in ArcGIS for Desktop? [duplicate]

Embarrassed that I haven't looked at this for some time (can't quite get the syntax down). (ArcGIS 10.2, Win7x64). Within Map Algebra (Raster Calculator) Trying to add the cell values of 3 rasters, ...
3
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1answer
38 views

Help with Rastercalculator - Filter areas with a certain height difference

I'm struggeling a little bit with the rastercalculator tool of QGIS. At the moment I am working with a DSM and a DTM. My aim is to filter all wind turbines out of the DSM and replace it with the ...
2
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4answers
93 views

IF else statements arcmap, using python

I have a shapefile with a number of fields. I have one field (let's call it Field A) that I need to populate based on another field (let's call it Field B). If Field B is greater then 0 I need it ...
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1answer
71 views

Spatial join multiple attributes from smaller polygons to the bigger one

I'm trying to join (to the rectangle) values from multiple polygons intersecting for this rectangle. I've tried to use some Reference functions in Field Calculator like geomintersects() but it joins ...
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1answer
189 views

How to convert text to proper case using the field calculator?

I am working on a set of data that has over 40,000 records on ArcGIS and I want to use a Proper Case for several fields/columns on the table. Is there a Python or Java Script that can help me automate ...
2
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3answers
137 views

How to calculate Statistics of an attribute field to use it in another calculation

I want the statistics of an attribute field to use in another calculation, i can view the statistics using the field properties menu I want these to normalised the data of field 'Ia' using the ...
1
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1answer
27 views

Summarize multiple columns in field calculator [closed]

I am performing the Huff model with 10.000+ facilities and dwellings. As a result, each facility has a value between 0 and 1 that determines the probability a consumer patronages a facility from a ...
1
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1answer
63 views

Copying some values from several columns to another column in attribute table? [closed]

I am trying to copy selected values from several columns to one single column in the attribute table. Specifically, where columns (Grid_code, grid_code1, grid_code2.... etc) have values of 4 and 10, ...
0
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0answers
9 views

Replacing null values in cell with integer using Python parser of ArcGIS Calculate Field tool? [duplicate]

In one field I have certain cells that are filled with null values. I am trying to change all those null values to 0 or say even as random as 100. I tried with the Calculate Field tool the following ...
1
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1answer
48 views

Capitalizing The First Letter Of Each Word In Attribute Field QGIS

I have tried capitalizing the first letter of each string in my field/column called "COMMUNITY" by referencing this post: Capitalizing The First Letter Of Each Word In Attribute Field Particularly: ...
3
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1answer
46 views

How to convert a “yyyy/mm” field to “yyyy/mm/dd”?

I am trying to edit an existing date field of the form "yyyy/mm" to a format that the TimeManager Plugin for QGIS can handle - I guess "yyyy/mm/dd" will do it. I've got as far as opening the ...
2
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1answer
70 views

Reproducing GRASS GIS network analysis tutorial in QGIS Field Calculator

Im looking to reproduce the assigning of road speeds as denoted in a GRASS GIS tutorial (v.net.alloc tutorial), where the road speed is assigned by road type (i.e. 'interstate' = 75 mph etc.) to then ...
3
votes
2answers
125 views

Arcmap field calculator python script returns no data

I am running ArcMap 10.2 I have 4 fields with which I am working. many have duplicate entries. in order to find the single correct entry from all the duplicates I am trying to calculate out the ...
2
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2answers
152 views

QGIS 2.12 attribute table update question

I'm trying to fill in a whole lot of cells in the same column of an attribute table all at once using the field calculator. Am I on the right track with the following expression? "Author" || ...
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1answer
250 views

How to copy same values to another field in attribute table in QGIS using field calculator?

I am trying to copy values from Parsel_ID to Parsel_NO using an equation ( look at pictures) in field calculator but it is not working. What is the problem and how can I success this task??enter image ...
4
votes
3answers
219 views

Using IF operator with Python parser of ArcGIS Field Calculator?

I want to assign numbers to a certain types of building and I need to use field calculator. I tried many different versions of this and I still cant find whats wrong. Could you tell me where do I ...
0
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1answer
158 views

Use Get Field Value tool to calculate field?

I am running a summary statistic on a clip to get acre counts by area type. I want to then add a second field that has the acre count from the total area. A third field be added so that it shows as ...
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0answers
38 views

Using timestamp field to auto complete source field in QGIS

I am trying to use my timestamp field to autocomplete my source field in QGIS using the field calculator. I want my source field to be completed with a saved string e.g "Sam_Sam". I want my source ...