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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Calculate Field with Python Issues (If statements)

I don't know a whole lot about python and scripting, so I was hoping somebody could give me a couple pointers on fixing some code. I am trying to calculate a "final results" attribute field. The ...
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90 views

count how many times an attribute is repeated, using “field calculator”

I'm using Arcgis 10.2.2 there is a way to count how many times an attribute is repeated, using the "field calculator" to make a selection after example of repeating more than 20 times
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90 views

How to work with accentuated strings in Python scripts in ArcGIS Desktop Field Calculator?

` pre-logic: def myCalc(name,nameVal): if (name == nameVal): return 1 else: return 0 var_name= myCalc(!Epulettipus!,"Lakóépület") ` This doesn't work with accentuated strings. (But ...
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2answers
296 views

How to concatenate double with string in field calculator with Python expression?

I'd like to concatenate my lat/lng with a few string fields in ArcGIS. What is the correct expression to use, avoiding VBA. I don't want to convert the lat/lng fields to string either. my 4 fields ...
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1answer
76 views

Calculation of a text value, The value of which is separated by a special character

How can I calculate a text value, the value of which is separated by a special character? For example: dog | duck, I would like to keep the first value: dog or elephant | cat, I want to keep ...
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5answers
198 views

Calculations in if statement

I want to perform a simple calculation with the Field Calculator using this piece of script (note that all the elif statements are attempts for another syntax and non of the worked): def ...
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1answer
630 views

How to sum up multiple columns values into one single column

I have one table containing many columns. Using field calculator, I want to create a new column containing (for each line) the sum of all columns values. Pretty dumb, but just cannot find the correct ...
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2answers
233 views

Creating a new integer field based on text in a different field - ArcGIS 10.1

I need to create a new integer field based on another text field. All instances of a the same text string in the existing field should be assigned the same number (starting at number 1). Can I do this ...
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3answers
1k views

Why do area calculations return negative values?

I have created a shapefile with some polygons and am now trying to calculate the area of these polygons. The original CRS was WGS84, I have reprojected it to WGS 84 / World Mercator so unit is metres. ...
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1answer
130 views

How to write a expression in field calculator for finding $X and $Y?

I'm trying to calculate the lat/long of points using the Q GIS field calculator.Nathan W suggested to First, save the layer as WGS84 and import it again. Then in the field calculator you can use $x or ...
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2answers
371 views

How to write a QGIS regex for rounding to two places after the decimal point?

In QGIS field-calculator round() is not working in QGIS 1.8 so I try to do the following with a regex: I'd like to keep the first two places after the decimal point - where do I go wrong? ...
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2answers
545 views

ArcPy Field Calculation with special characters

I'm trying to calculate a string field, using "µSv/h". Running this in the manual field calculator works just fine, but I've tried this in the Python window in ArcMap as well as the IDLE, but both ...
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1answer
82 views

How to fill inn A, B, C …Y, Z, A, B, …Y, Z, A, B, and so on? [duplicate]

as a second part of a problem i am trying to solve. I need help to figure out how to fill in serial letters.. Starting at A.. going to Z and starting over at A again.. I have a tabel with numbers ...
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1answer
166 views

Calculating values of field based on two others using Field Calculator in ArcGIS Desktop?

I need to combine two fields in an attribute table. I want to do this using the field calculator. What is the proper script to write to combine a field called "name" and "type", so that it produces ...
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3answers
841 views

Automatically assign numbers to point file in various order in QGIS

I know how to automatically assign numbers to a new point files using the $rownum function in the field calculator. However it does it from the top-left over and down like reading a book. I could ...
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1answer
46 views

Conditional Statements in Arc Map 10 (field Calculator)

I'm attempting to calculate the values of a field based on IF THEN statements in ArcMap 10 (in field calculator) but I haven't succeeded yet on that. What I want to add is the following expression: ...
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1answer
53 views

CalculateField with variables

I'm trying to make a python script on arcmap 10.2.2 which will copy values from an old field (selected by the user) and paste them in an new field (named by the user). I wrote that: fc = ...
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1answer
60 views

Create new attribute ranking polygons by size in QGIS

I'd like to create a new field in the attribute table which gives the rank of the polygon by size. For example, the polygon of the largest size would be rank 1 and the smallest rank N. I was hoping ...
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1answer
56 views

Add and Calculate Field in Table with ArcPy?

I have written the following script to iterate it as a tool for all my tables with ModelBuilder, but i have a problem wth my codeblock. I want to add a field FID to all my tables and to add the values ...
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2answers
46 views

How to update a bulk selection of fields using field calculator in QGIS 2.8.1

I have an attribute table showing vegetation communities. The table has three columns ("ID", "Veg Comm" and "Area_ha". Instead of having to copy and paste text after each polygon created into each ...
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2answers
46 views

How to remove a certain number of digits from the front or end of an attribute field?

Can I use the filed calculator in QGIS somehow to remove the first 4 numbers in all attribute fields in a column? Example 16011234 -> 1234 EDIT: Silly, I can just subtract with 16000000 in this ...
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1answer
59 views

ArcGIS Field Calculator nested elif is None not working

I am calculating a field based on two other fields in ArcMap 10.2 using python. My Pre-Logic Script Code is def myfunc(legend,Btype): if(legend == 'Apple'): return 'Banana' elif(legend == ...
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1answer
89 views

Calculate field based on other two added fields in ArcGIS Model Builder

I have a model in model builder where I add 2 fields, "field 1" and "field 2". For each field I calculate their values using the calculate field tools. Afterwards I add a third called "Field 3" of ...
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2answers
176 views

Cannot convert string to int using ArcPy Calculate Field

When I load a csv file to join with ArcPy, it converts all string fields that are numeric to integers. Therefore, I have to add another field within the feature class that I'm using for joining that ...
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3answers
67 views

VB Script field calculator - error with conditional statements

I have limited VB Script experience, but have been working on the script below and keep getting errors, the most common being "expected identifier". Can someone tell me what I'm missing here? Dim ...
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1answer
89 views

How to perform If Statement in Field Calculator of ArcGIS for Desktop? (Python or VB)

I've one field "MAXSPEED". I want a Field Calculation that will calculate an additional field ("noise"): If MAXSPEED > 40 then the term: (73.5 + Log ( 25 ) * ( [MAXSPEED] / 50)) should be used to ...
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1answer
47 views

how multiply a ranges of values for other value on python

I need multiply ranges>1.5 and <=4.5 * 9, but I am new in this type of language. please help me. def CalcD(Level_water) if Level>1.5 and <=4,5 * 9
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2answers
268 views

What's wrong with this VB Script code for the field calculator in ArcGIS 10?

I am trying to use one field's contents ([Condition]) as a condition for populating another field ([Intact]). I try to run the following code in the Field Calculator, but it never works (and is not ...
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1answer
170 views

Calculate value from an equation using Field Calculator Python/VB Script

I wanted to calculate a result value from 3 fields using an equation. VBScript or Python codes are also accepted..:-) the equation is RESULT= [(R^2/3)(S^1/2)]/n..
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1answer
324 views

Slow performance with Add Join and Calculate Field?

I have a point layer and a table with approximately 100 fields. I need to join the table to the point layer based on a key field and create a new shapefile / feature class. This script has been ...
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1answer
97 views

Calculating Field B from Field A, except where Field B has existing value, using ArcGIS Desktop 9.3?

Im trying to calculate Field B from Field A except where Field B has existing value in ArcGIS Desktop 9.3. (I suspect its straight forward but I have 'searched' and havent cracked it yet) Any ...
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3answers
242 views

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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2answers
126 views

How to include a quotation mark in a text field from field calculator

I'm trying to attribute pipe size and need to include a quotation mark in a text field. How do I include that in the field calculator. "4"" doesn't work.
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1answer
83 views

Python in ArcGIS, CalculateField_management, updating with single value

I have a float field which I want to simply update all values with 1. I can easily do this within the field calculator but I have started using python today, what is the syntax to simply update a ...
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2answers
170 views

Iterate through each county in a shapefile, select the county and make a second selection by location - modelbuilder

The goal of my project is to create a table with two fields. The first field showing a county name and the second field listing every county that touches the boarder of the county listed in the first ...
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1answer
99 views

Use field calculator in QGIS so get number of points in polygone and store it in attribute table

I have to layers, one point one polygon (with 6 areas) stored as shapefiles. Now I want to count the number of points in each area and write it into the attribute table of the polygons. A column ...
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2answers
1k views

How to fill attribute field of one feature based on calculation on attribute field of another feature

I would like to fill an Attribute field of a geodateabase table based on some calculations such as 'sum' over specific field of another Feature class. Is there an Approach to formulate it? while in ...
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1answer
318 views

How to concatenate XY values in attribute table without messing up the numbers in ArcGIS 10.1?

Here's the procedure I use and the resulting problem I'm having. First I use the Add XY coordinates tool to add POINT_X and POINT_Y fields to the attribute table of a point layer. I then add a new ...
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1answer
289 views

Stuck updating one field based on the condition of another using Acrpy or Field Calculator

I have a shapefile with 5,000 city points. I need to populate a new field, "cls_pop", based on each cities population, so that cities with a population > 2,000,000 will have "cls_pop" = 1, cites with ...
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2answers
491 views

area values determined with field calculator become null when saving

using field calculator in Qgis 1.8.0 to get the area, it shows just right at first but when I save it, the values become Null. help please
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1answer
1k views

Concatenate Fields into One Field in QGIS

I have seen some posts on this, but only for ArcMap. I am looking to take a range of values from two fields and concatenate them into one field to make a unique value. For example: XMAX YMAX ...
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2answers
467 views

FieldPyculator Plugin - How to Classify Fields?

Could someone tell me how to classify/populate fields with QGIS FieldPyculator Plugin? In the Attribute Table, I have a field named POPULACAO with population data: I want to apply a weight to ...
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1answer
262 views

Small issue with field calculator

What am I doing wrong in this field calculator logic? Pre-logic def re_score(elev_t,f2, contour): f2=contour if elev_t.endswith('.5'): f2 = "Midi" return f2 Expression for field "Contourtyp" ...
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1answer
346 views

How to tranform a column field into a list using Field Calculator

I'm trying to make a simple field calculation with ArcGIS 9.3: New field = Old field - Old field(first value) which in Calculate Field with python code should be Expression: !Old field! - first ...
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1answer
32 views

How to delete char in table attribute in QGIS 2.6.1

I need to label many items but in the table attribute field there are some char (#F) for every item that I have to delete. The length of the description are not always the same. I create a new field ...
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58 views

delete a space with the field caculator

I would like to delete the space in this number like this 'F00 089' with the field-calculator. Is theres a function in the field-calculator? ! see my screenshot
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1answer
53 views

Field Calculation Python acceleration of gravity [closed]

In my problem i have a column DISTANCE and a column TIME and i want to calculate with python in field calculator how much time it needs to make that distance (for example 1000m) if you are moving with ...
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1answer
104 views

Area is calculating wrong using $area in field calculator (QGIS 2.8.1-Wien)

There is a similar question posted, but the solution to it seems to be that polygons were multipart: Wrong $area from field calculator (QGIS) In my case, all polygons are singlepart. I have several ...
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1answer
62 views

Calculate area intersected areas, problem

(I'm working in QuantamGIS) I intersected two layers creating a new layer. Within the attibute table of this new intersect layer i would like to calculate the new areas. However, it just doesn't ...
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1answer
84 views

How to fill the column in attribute table with same values?

I have about 19000 records, I added new column and I would like to fill it with string values (eg. brand)- same value for all rows. I'm not considering copy/paste. I know I could do it with exporting ...