Questions tagged [calculate-values]

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9
votes
3answers
2k views

How to calculate total PV potential of a roof using QGIS?

I want to calculate total PV potential of a roofs in a certain area. To do that I made a dsm, ran SAGA "Potential Incoming Solar Radiation" algorithm (just playing with it only for now - I need to ...
9
votes
2answers
836 views

QGIS calculate radius of an arc to attributes

I have QGIS 2.18.16 installed. My problem is, how to calculate radius of an arc / curve feature (line)? The lines are originated from .dgn file, which I read with FME and wrote to PostGis DB. I have ...
7
votes
3answers
388 views

Use field calculator QGIS: if value in one column, then value in new column

I am having troubles using the field calculator to get what I want. One column in my attribute table is named 'Taxa' and has a set of species in it. Species are separated by #. I want to make a new ...
7
votes
2answers
242 views

QGIS 3.4 calculate date, add month

I want to add a number of months to a date to get a new date. I have a date-field "date", an integer-field "months" and a date-field "new_date". I want to calculate the "new_date" by adding the "...
4
votes
2answers
74 views

How to calculate and export tasseled caps from MODIS collection in GEE?

I would like to calculate and export the brightness, greenness and wetness tasseled caps for the MODIS MCD43A4 V006 collection based on the Lobser coefficients, but I have no idea how to do it. var ...
3
votes
1answer
232 views

Calculating weighted values of field in Attribute table in QGIS

In QGIS in the Attribute Table, I have a field with values. For this field, I need to calculate the Sum of all its values and divide by the number of values that are not equal to "NULL". Afterwards, ...
3
votes
2answers
555 views

Extracting data from HTML field in table using ArcGIS Desktop?

I'm operating ArcGIS. I need to make a calculated field. The value of the field is a sub-string of one of the other fields. My problem is that the other field (PopUpInfo) is an HTML string: An ...
3
votes
1answer
207 views

Calculating sequential values in ArcGIS Desktop?

Previous posts (such as Adding automated values to attribute field?) answer how to calculate sequential values in an attribute table. The posts all seem to rely on the process described in this ESRI ...
3
votes
1answer
1k views

Replacing Negative values with “0” for raster layer

I am trying to change negative values (raster layer) into "0" but I cannot find a way to do that. Does anyone know how to accomplish it in QGIS 3.2? I found an answer somewhere on the Internet to ...
3
votes
1answer
96 views

Calculating acreage as a percentage in ArcPy

I am struggling to calculate the acreage as a percentage in Calculate Field Management, but I am getting this error message: "ValueError: could not convert string to float! BufferAcreage! arcpy....
3
votes
1answer
401 views

Using the field calculator in SAGA-GIS

I am working with SAGA-GIS and need to create an euclidean allocation raster. For this, I need to first create an integer raster with values for certain areas. This integer raster shall be based on a ...
3
votes
1answer
47 views

Calculating field while dissolving

I have two polygon Layers, A and B correspondingly. The polygons of B are lying on top of layer A and also overlapping the polygons of A (I made an example of the attribute table for better ...
2
votes
1answer
3k views

How to calculate the polygon area and create a column of results in R

I'm working with shapefile in R and I need to calculate the polygons' area that I created by Gdiference function, So ,now I need to create a column with the size of freshly polygons created, because ...
2
votes
1answer
51 views

Saving calculated fields to reuse in other QGIS projects

I am using QGIS 3.4. I want to make attribute tables with many calculated fields that link to styles, and reuse the same structure for many projects. For example, when I draw a pipe (line vector), ...
2
votes
1answer
102 views

How to use the field calculator in QGIS to determine the total of differents fields

I have an attribute table with 7 fields. I want my attribute " A1 " to be the total of " IP1 to IP5 ". I am not familiar with the request in the field calculator. How can I calculate the value of ...
2
votes
1answer
979 views

What is the Python expression for calculating Lat/Long in Decimal Degrees in ArcGIS?

I'm calculating 4 double fields for a polygon feature class (exploded, single-part features): SquareFeet, Acreage, Lat, and Long I found the correct python expressions to calculate SquareFeet & ...
2
votes
1answer
38 views

Determine distance between two polygon with having unique id

I have two polygon feature class one is Source Data and other is shifted data. I want to calculate how much polygon shifted (distance) using ArcGIS 10.6.
2
votes
1answer
68 views

Calculating partial distances from whole segment in grid using QGIS?

I am using QGIS and trying to find a way to calculate partial distances of lines in a grid. In the left part of the picture you can see the sum of the line lengths within the grid cell (108.96...), ...
2
votes
1answer
287 views

Calculate mileage river network

We have a river network which doesn’t correspond to the reality shown by the orthoimage. Each river has the same route number (see attribute table). Every route number has several segments (see ...
2
votes
1answer
1k views

when given bearing, angle, and distance, how to find change in location in 3d

I am helping a drilling team find the surface location representing a point in the ground. I am given the following values: surface location latitude and longitude Drilling depth (length of drill ...
2
votes
2answers
2k views

ModelBuilder: Using Parse Path in iterative model to include folder name in output file name

I have a simple model in ModelBuilder that does the following: Iterate through a folder of rasters (these are outputs from Global Climate Models) Clip each raster to a study area (Egypt), using a ...
2
votes
0answers
34 views

QGIS 3.10: Evaluate default values (data source preference) not staying checked on?

Anyone having trouble with "evaluate default values" in QGIS 3.10.1 preferences, under "Data Sources"? When I click the check box and then "OK", I go back to preferences it's unchecked! And default ...
2
votes
0answers
52 views

Calculate side of a polygon that touches another feature [duplicate]

How can I measure the length of the side of a polygon that touches another feature (calculate from A to B on the image below)? I'm creating and measuring lines to figure out the lenght of the '...
1
vote
1answer
61 views

Updating Field using similar Field w/ Update Cursor: Field does not populate

I'm pretty new to scripting with Python. My code is intending to iterate through a list of feature classes within a GDB, creating the fields EF_Type and EF_Group, then calculating the field. The ...
1
vote
2answers
42 views

Adding time to variable using Python Parser of ArcGIS Calculate Value tool?

I am using Python 2.7 in calculate value in ModelBuilder. I want to query both 30 seconds before and after the variable. The original value keeps returning not the time change. What am I not defining? ...
1
vote
1answer
176 views

NameError: name '**' not defined in ModelBuilder Calculate Value

This question follows up on Crianopa's answer https://gis.stackexchange.com/a/107687/126329 - I am attempting to do just this, but my model fails at the Calculate value stage. Using the expression ...
1
vote
1answer
30 views

Add and Calculate Fields of Iterated Annotation Classes

I'm have difficulty with my script Arcmap v10.5.1. I get a syntax error on line 8. My question is: Can I calculate the Added field from an existing field within an iterated value? If so, what's my ...
1
vote
1answer
36 views

Finding calculate value or collect values tools?

I am using ArcGIS Desktop 10.5.1 and I need to use the calculate value tool or collect values tool to in ModelBuilder, but I cannot find those tools. Do I need to download them from somewhere else?
1
vote
1answer
156 views

Inherited values between polygons in QGIS? [duplicate]

In this project, I have three polygons, see the image below "Polygons_From", includes input attributes, i.g. "Value_1", "Value_2", "Value_3", and $area for each quadrate (on the image there are two ...
1
vote
1answer
60 views

Performing calculation in neighborhood 3x3?

I'm looking for the way to perform some calculation with each cell in neighborhood 3x3 and assign value to center cell. For example I'd like to sum z1 with z5, z2 with z5 etc. and then assign average ...
1
vote
1answer
40 views

Code to return false if two preconditions are false in Modelbuilder

I'm trying to use Calculate Value in Modelbuilder's Arcmap to run a process if one of two booleans preconditions is true. So if both of precondintion are false the process shouldn't run, otherwise it ...
1
vote
1answer
278 views

How to automatically get/assign contour height attributes?

I have quite a simple problem yet I can already guess the solution is going to be pretty complicated. I'm using QGIS and was wondering if there is a simple way for the computer to automatically assign ...
1
vote
1answer
367 views

Seeking point statistic tool in QGIS?

Does anyone know if there's a tool in QGIS that is equivalent to ArcGIS Point Statistics? I need to create a raster with values from an attribute in a Point layer.
1
vote
0answers
37 views

Calculate ID based on ID from another field

I have a layer with single lines and I have added a unique ID for each line. I have extracted the vertices of these lines to a new point layer and now I want to add a new ID for every point but based ...
1
vote
0answers
19 views

Help with “Calculate Values” Python expression (ModelBuilder)

I have a model and need to compute a new value from two other values upstream, and then feed the new value to the Kernel Density tool. Here is the formula I am trying to reproduce in the "Calculate ...
1
vote
1answer
402 views

Calculate percentile value of raster

I want to set null all raster values that fall below the 75th percentile value. E.g. If you classify the raster by quantile method into 4 classes I want to be left with the top 25% percentile. For the ...
1
vote
0answers
528 views

Standard Method to calculate Average Moving Speed from Times & Coords?

...I wasn't sure if this question was best suited to GIS, SO or Math, so after reading GIS Topics I decided to ask here, but I'll relocate if necessary... :-) I'm working on automating various ...
1
vote
0answers
176 views

Calculating percentage of area from polygons inside one polygon in ArcMap?

I need to calculate percentage of different areas contained in one Cadastral parcel. Every parcel (polygon) is overlapped with one or more polygons. I need to find percentage of every overlapping ...
1
vote
0answers
249 views

Calculating normal vector distance between two surfaces using ArcGIS Desktop?

I have two surfaces mapped out from seismic data, imported as x,y,z datasets in ArcMap and then converted to rasters using the point to raster tool. These surfaces are rugose (seafloor and an ...
0
votes
1answer
113 views

Calculate new Lat/Lon from initial Lat/Lon plus Cartesian X,Y [duplicate]

For small distances (below 10 km), assuming Earth is flat and I have initial Lat0/Lon0 and I have X(km), Y(km) distance From Lat0/Lon0, how can I calculate new Lat/Lon for the added X,Y?
0
votes
1answer
27 views

How to write it on ArcGIS Raster Calculator?

I just started using the Raster Calculator, so I don't know how to build the formulas. How can I do this? I need to write both of these formulas: D = is a raster file called "Slope_2" P = 13
0
votes
1answer
42 views

Color grid if values in grid exceed threshold - species distribution in QGIS

I have distribution data of a set of species (plants, mosses and lichens: 13 species total) in the Netherlands. I made a grid that divides the Netherlands into 1x1 km squares. I am not interested in ...
0
votes
1answer
152 views

Using ouput data variables in subsequent calculation within ArcGIS ModelBuilder?

Using ArcGIS Desktop 10.3.1, I have two simple polygon shapefiles, each with just a single feature. I'm new at ModelBuilder, and have 2 tasks: calculate the acreage within each of the two shapefiles,...
0
votes
1answer
39 views

Using IF-THEN-ELSE with ModelBuilder of ArcMap

I have two optional parameters in my ArcMap model (City and date) and I want to use the tool calculate a value to create an expression that will give me a boolean (true-false). I want the code to ...
0
votes
1answer
31 views

Error with equation in GEE

I'm trying to calculate values for a raster I have based on other raster values. The problem is that I get the error: -0.054.multiply is not a function and I believe it is because I'm writing ...
0
votes
1answer
83 views

Wrong masked pixels

I am new in GEE, and tried to run a simple code to mask cloud pixels. However when I added the image selected with my filters I saw that the result of the cloud filter are empty areas, as shown below: ...
0
votes
3answers
108 views

Model Only calculate value with zonal statistics as table

In a precedent post Multiple Output for Zonal Statistics as Table I was trying to have as many table in the output as the rasters in the input. To overcome my errors, I decided to add a "Model Only ...
0
votes
1answer
60 views

Converting string to float in Calculate Value for ModelBuilder?

In ArcMap 10.2 I have created a nested model where I am iterating through some feature classes in order to get the minimum value of a specific field for each of them and then collect the outputs using ...
0
votes
1answer
196 views

How to determine the average NDVI value of a selected area?

I'm new to ArcMap 10.2 and trying to get NDVI data of city centers. So my problem is, after I'm calculating the NDVI and getting the result raster, I would like to get a mean (average) value of ...
0
votes
1answer
260 views

Weighted average of areas within zones

I have a fishnet that defines my zones for my analysis, and am interested in the area of different hydrologic soil groups (A, B, C, D) within these zones. Each soil group has a corresponding score (1, ...