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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677 views

Concatenate multiple string / text fields some of which may have NULL values ArcGIS

I am trying to repeat the behavior of this code from the ESRI website. I want to replicate the output example in ALL_Type field, so that it concatenates a field but it deals (ignores) any that have ...
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1answer
128 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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1answer
79 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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1answer
325 views

Adding an “m” to the end of every number in a row

What function do i need to use to add an space and an m after every item in a row, using the field calculator in the attributes table. I have a load of numbers (as strings) and would like to add m ...
2
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1answer
139 views

How to convert unix time to qt time type?

How can I convert unix timestamp to qt time type using qgis field calculator? I would like to avoid importing my table into excel and convert the timestamp to qt time type.
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1answer
509 views

Python Syntax Error when running Python Snippet of successful geoprocess

I am having an issue with a simple python snippet. Here's the background: I wanted to include an additional step in a nightly update script that replaces characters in a field that simply do not play ...
4
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1answer
636 views

Calculate Field in ModelBuilder gives General error executing calculator. ERROR 999999: Error executing function. Expected end of statement?

I am attempting to do zonal statistics for multiple images and I need to add an extra field that will have the name of each raster file in each row to the finally appended file. I have added a field ...
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1answer
236 views

Field Calculator If/Then in ArcGis 10.1

I've been looking through these threads, i found something similar and thought it could be the answer, but it doen't seem to work for me... I could do this the slow way with Select By Attributes, but ...
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510 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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3answers
5k views

Setting Zero values back to NULL

I'm working with ArcGIS 10.2 for Desktop and OS Windows 7. I need to set numeric vales from Zero back to NULL, but I can't from the field calculator. I'm working with a vector file and I need to ...
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105 views

calculating decimal degrees from coordinates found in an excel table

What is the exact syntax to use when calculating decimal degrees in the field calculator? I know the general formula {i.e. Degree + (minute/60) + (second/3600)} but how do I put this into the gis? I ...
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317 views

How to calculate percentages using QGIS field calculator expression?

I am new to QGIS. I am wanting to calculate a field using other fields and some operators. Here is my expression: case When "RVM_CAT" = 'B' OR "RVM_CAT" = 'C' Then ("PC1" /100) * "RE_ha" When ...
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1answer
185 views

Can you use wildcards for column headers in Field Calculator?

I know you can use wildcards for fields like so (in the Field Calculator): case when "column" ILIKE '%example%' then 1 else 0 end Can you do something similar for the column headers themselves? I ...
2
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1answer
207 views

Populate field with current time

I am trying to populate a field with the current time. Here is what I tried that did not work: Start editing Open Attribute Table Add Field -> Name: time Type: Date Right Click on Field Name ...
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31 views

How to get Subtype name in Field using field calculator [duplicate]

I would like to get feature subtype name in another field using field calculator. Any one can advise to make this success? I am expecting ".Cal" file code using with Field calculator.
2
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1answer
138 views

Problem with Python codeblock recognizing a field

'<'First Post Alert> I've been through multiple iterations / gyrations, and while there may be multiple problems here (and I'll appreciate feedback on all of them), the recurring issue is that the ...
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2answers
183 views

Calculate Field Syntax: If statement over many fields

Apologies if this has already being asked but I couldn't find a page pointing to this problem. I'm struggling with the python syntax in the Calculate Field so that, in the table above: if b, c, d, ...
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1answer
495 views

How to SUM field and then insert into NULL column?

I am only in the beginning stages of learning Python. I have a column, 'QUANTITY_SOLID', that I want to take the sum of all of its rows. I understand I can do this with 'SUMMARY_STATISTICS', but i'm ...
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0answers
192 views

Warning 000405 when trying to calculate field [closed]

I am trying to create a model but am getting hung up on my first step. I need to calculate an ID field from an FID field so that I can join it to another table based on the ID field. So I have a ...
3
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1answer
160 views

How to find and replace a singe word in a string?

How do i find and replace a single word of a string? e.g. Calle Iparraguirre to Iparraguirre I've tried: replace( 'Calle\\s', 'Calle\\s', '') replace( "name",'calle','') and all combinations ...
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1answer
94 views

Sum a field in buffer intersection

I have looked and do not see this answered in any other discussions. Purpose: Site suitability analysis for brewers spent grain processing facility Method: Locate intersecting buffers with greatest ...
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1answer
117 views

Use Field Calculator to change “Status” field in Annotations

I am trying to turn off a lot of annotations at once by using Field Calculator to set status to Unplaced. Just typing "Unplaced" into the expression, I get this error: The calculated value is ...
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2answers
98 views

assign a number for each group in field calculator

I have several thousand features each of which has a name. The names are not unique. what I want to do with the field calculator is assign a number to each name so I can refer to a number and always ...
2
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1answer
2k views

Adding count of features in categories to legend using ArcGIS for Desktop?

I am using ArcGIS 10.1 for Desktop and I would like to know How to add the Count (which is visible on the Symbology tab of the Layer Properties dialog) to the legend?
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3answers
389 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
68 views

Field calculator fails when computing First X coordinate in ArcGIS10

I have this line in python to compute First X coordinates into the Field Calculator from each polyline: !Shape!.firstPoint.X Then, when I inspected the attributes I see this rare thing: You may ...
2
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1answer
131 views

How to return end of string up to a certain character using Field Calculator?

I am trying to accomplish this task: http://stackoverflow.com/questions/15851568/how-to-get-the-last-part-of-a-string-before-a-certain-character within the Field Calculator. I have the below but ...
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1answer
114 views

Field Calculator not showing some fields

When I open my attribute table, click on a column, and select Field Calculator it opens and doesn't list all of the Fields in my attribute table. Why can't Field Calculator find these Fields?
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1answer
381 views

ArcMap 10.1 Crashing when using field calculator

I keep getting a serious error message when I try to use the field calculator. I've joined a .csv to my SDE feature class and am trying to set one of the columns equal to one of the columns from the ...
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1answer
327 views

Updating a feature class

I am working on ArcGIS 10.2.1. I have a feature class containing more than 4000 records and a table having approximately 1000 records. Both feature class and table have some common fields however, ...
4
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1answer
193 views

Extract one GPS fix per day from data?

I am in the fortunate position of having 2 years worth of animal movement data. With such a large amount of data I would like to extract only one fix per day to make it easier to work with. Data = 14 ...
0
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1answer
111 views

What is the syntax for Python 2.7 to permanent display in percent in a field column?

What is the syntax to build to calculate field, for example, Acres to Percent? 841173.00 to 82 % What I want the field column in Percent to be display numbers with percent with the alignment to ...
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2answers
183 views

Randomly choosing one from multiple fields in Field Calculator of ArcGIS for Desktop?

Using the Field Calculator in ArcGIS for Desktop, I want to randomly choose one field from a list of 10 fields (strings). The Excel equivalent, which is working, is: =INDEX(A2:J2;rnd()*10+1). How ...
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3answers
142 views

Calculation based on features in shapefile

I hope I get the terminilogy right! Correct me if I mess something up. I need to perform some calculations for a scoring system for different habitat types. The Problem is that I have two different ...
6
votes
1answer
360 views

How to classify time periods in a new field, using Python?

I have a datetime field (Horario) in my feature class, showing only the time. Although the date doesn't appear, it seem to be stored automatically as 30 Dec 1899, I'm not sure why. I want to use ...
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1answer
520 views

Calculating Area of Raster Classes

I have a raster in a GRID format that was created by Image Classification. The GRID is projected in StatePlane meters, but I would like the area in square feet. I'm assuming I will need to use the ...
3
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1answer
320 views

Calculate population coverage?

I am relatively new to QGIS and hope I explain this right. I am looking at the percentage of an population that has geographical access to healthcare. Therefore I have one shapefile with village ...
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5answers
228 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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4answers
80 views

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 ...
2
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1answer
197 views

QGIS: Expression WHEN property1 = 'FOO' THEN property2 = 'BAR'

Our Foundation is adding additional properties to points. If property1 = FOO , then add property2 = BAR WHEN property1 = 'FOO' THEN property2 = 'BAR' END When I run this the ...
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2answers
107 views

Call field from zip() into Field Calculator expression ArcGIS

I've been trying to find a way to call in field names from a zip(). Basically I have 12 fields called "Flw_days1", "Flw_days2" etc and corresponding "Depth" fields that need to be calculated using the ...
0
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1answer
59 views

Interaction with two variables as parameters, saving the raster properties output into a table (.dbf)

The draft of the model below TASK: I need to calculate the percentage of river channel that is covered with shadow in each timestep RESOURCS: I have values for azimuth and elevation of the sun ...
0
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1answer
53 views

How to implement a Gaussian function in field calculator?

Are there any build-in functions like Gaussian or Epanechnikov functions in field calculator? Or I have to write that by myself?
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1answer
97 views

How to use Fields in the Field Calculator? [duplicate]

I'm using the Field Calculator in ArcMap and I need to create a unique ID for every storm drain in my county. An ID Should look something like this: 16-I-003 The first number is the municipal number ...
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2answers
217 views

Conditional Calculate Field Many to One

Anyone have experience calculating a field based on a many to one scenario? I have a feature class in a geodatabase with a field of unique names. Feature Class Table (let's call this ...
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2answers
273 views

Using the Rule-based style to calculate each grid cell from overlaps

I am using the Rule-based styling properties (QGIS 2.2) to determine the colour of grid cells for a merged shapefile. Each grid cell defined by its ID may be overlapped by several layers as defined by ...
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4answers
3k 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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2answers
309 views

ModelBuilder - How to calculate Field using part of path name

I am trying to calculate a field using part of the feature class path name (specifically, the last three characters of the geodatabase name). Is this possible? I've tried using the parse path tool and ...
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2answers
60 views

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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1answer
619 views

Deriving Z-score values for given field using ArcGIS for Desktop?

I have a shapefile with an attribute field with a range of numerical values. How do I derive z-score values for this field using ArcGIS for Desktop?