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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55 views

QGIS - Field Calculator: scale_linear gives unexpected result

When I try to use scale_linear, its output isn't as I expected. My values are from 1 to 16, so I set domain_min = 1 and domain_max = 16. I want to interpolate to interval from 1 to 4 so I set ...
2
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1answer
84 views

Rename cells in Attribute Table to 'XXX.$ID'

I feel like this should be easy to answer, but I can't get it to work for me. I need to edit the attribute table of a .gpx file before I load it into my GPS, in order to label the points. I can rename ...
3
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3answers
85 views

Can't replace attribute with field calculator

I have an attribute table where one of the columns (laeskaerm) has been edited/created by checkboxes on 2 different machines. Result: it contains both 1, 0, true, false and NULL I'd like to replace ...
1
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2answers
80 views

How to compute the distance from the current polygon centroid to another in QGIS field calculator?

There is layer with polygons. I want to save in new field distance of every polygon's centroid to centroid of one particular polygon. To do this I should write some expression like this: distance(...
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1answer
72 views

How to edit virtual field definitions in QGIS?

I have a virtual field in QGIS. The values are updates depending another column with a concatenate CASE statements. I would like to edit this statement but I cannot see it. I have attempted to use ...
2
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1answer
95 views

QGIS processing toolbox: fieldcalculator - update only selected features is not possible

I am working on a model where I need some calculations on only some selected features. In the normal fieldcalculator you can check 'only update ... selected features'. When using the fieldcalculator ...
2
votes
1answer
142 views

Using ArcMap Field Calculator to count number of identical values?

I have a file with an attribute table with data in 3 columns, and would like to use field calculator to populate a 4th column. The data is integer numbers between 0 and 56. I want the new column to ...
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1answer
71 views

Polygon Surface Area Calculator in different map projection(s)

I'm simply looking for an online tool or a utility to calculate the surface area of the same polygon (i.e shapefile) in different projection (projected and geographic projection system) systems. It ...
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1answer
51 views

Calculating field gives invalid expression in QGIS?

I am a new user of QGIS and I want to add a new field in my attribute table named densite which can be calculated by POP(population) / Area, in Field Calculator, I wrote POP/Area no result !! invalid ...
2
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3answers
59 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
votes
2answers
43 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
30 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 ...
1
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1answer
47 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 <= 50)...
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0answers
66 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 ...
1
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2answers
168 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
107 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 ...
2
votes
3answers
62 views

Stacking multiple selected points in ArcGIS

I would like to find a way to stack multiple selected points in ArcGIS, either using the field calculator or python script. For example, I want to snap all points representing houses on a street into ...
2
votes
3answers
328 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
48 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
votes
2answers
131 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 ...
1
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3answers
354 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. ...
0
votes
1answer
89 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. ...
0
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2answers
35 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
175 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
13 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
47 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
25 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
votes
1answer
139 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
87 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
38 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 ...
0
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2answers
61 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 ...
1
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1answer
50 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 ...
0
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3answers
117 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
148 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 points,...
2
votes
2answers
64 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
84 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
61 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
votes
1answer
108 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
votes
1answer
72 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
votes
2answers
485 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 ...
1
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1answer
47 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 ...
-1
votes
1answer
74 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
votes
1answer
47 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
votes
4answers
101 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 ...
1
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1answer
98 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
321 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
votes
3answers
196 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
35 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
84 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
11 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 ...