# Questions tagged [angles]

From Wikipedia: In geometry, an angle is the figure formed by two rays, called the sides of the angle, sharing a common endpoint, called the vertex of the angle. Angles are usually presumed to be in a Euclidean plane, but are also defined in non-Euclidean geometry.

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### Trying to find zenith and azimuth angles to satellite

I am working with satellite data. Each scene is approximately 30km squared with 1024 * 1000 pixels. I have the zenith and azimuth angle for each of the four corners, plus the center. I have latitude ...
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### Creating tangential lines at points along shoreline in QGIS

I want to create tangential lines for each point along a shoreline in QGIS, such as the dashed line I've hand-drawn. These points are not randomly spaced, they each represent the angle at which each ...
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### Offset QGIS label for vector field markers, rotate and anchor them so they are fixed regardless of scale

Working in QGIS 3.34.3 Prizren and have a points layer visualized as 2 blue vector field marker arrows (visualized by angles called angle rbear & lbear respectively). The grey arrow is the 3rd VFM ...
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### What is "ANGLE" in an ArcGIS.com ADDRESS_POINTS table?

Starting at e.g., https://gisdata-dupage.opendata.arcgis.com/datasets/address-points/explore how does the user find what the ANGLE (type: esriFieldTypeDouble, ...) field represents? Angle measured ...
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### How to determine apex / angular points in QGIS-3

How could I find the apices / angular / turning points of a linestring in QGIS3? The logic behind that should be to determine consecutive segments with same direction (always right or always left), ...
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### Calculating main_angle of polygons using PyQGIS

According to Calculating Polygon Main Angle using QGIS, it is possible to find the main_angle of a polygon by using a field expression like: main_angle(\$geometry) Can this function be called using ...
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### Labelling line with angles from 0º to 360º in QGIS

Labelling lines with the following function: round(degrees(atan2(yat(-1)-yat(0), xat(-1)-xat(0))), 1) || ' º' As you can see in the screenshot, this expression calculates the orientation angle of the ...
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### Rotating features with multiple geometries in one layer using PyQGIS

I have a layer containing several small square geometries in QGIS. I want to tilt these ones by one to the same angle. So I wrote the following Python code for that, but it does not work properly. ...
259 views

### Create line-type symbology perpendicular to a segment in QGIS

I want to create a symbology (line type) for a point layer in QGIS. This line must be perpendicular to the segments of a polygon. I attach an image: To do this I entered an expression in the rotation ...
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### Line geometries thematized by graduated size according median length and angled by median angle

I would like to find a dynamic method, using a Geometry Generator expression, to draw a categorized lines geometries from a range values of lines angles I try to expose the initial state of the lines ...
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### Create raster with angles between single point and all raster pixels in QGIS [duplicate]

I would like to create a raster in which the cell values contain the angle between that cell and a single vector point. It would be as though a line were projected between the cell and the point, and ...
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### Why angleAtVertex() returns different value than angle_at_vertex in Field Calculator using PyQGIS

When using angle_at_vertex(\$geometry,0) 324.022 in the Field Calculator of QGIS the values seem correct from a visual check. However when using feature.geometry().angleAtVertex(0) 5.616644978134382 ...
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1 vote
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### Combining lines with similar angles in QGIS [closed]

I have a lines layer representing hedge lines. Each hedge is split at a 'junction'. I want to combine the hedgerow lines that are travelling in a similar direction to have only one hedge line. I can ...
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### Is it possible to keep rotation values relative to the north in line pattern fill when making a print layout with rotation in map?

I have a polygon that I am displaying with Line pattern fill. The orientations of the pattern fill is set by an attribute in the file with the value of the angle rotation. I am creating a print layout ...
• 426
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### Determine the heading of a polygon by the longest side

I want to add direction arrows of polygons based on first drawn points of a polygon in QGIS. Heading of a polygon should be also added to a column heading of polygons layer. The solution should be an ...
1 vote
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### Understanding latitudes longitudes and angles

I am very new to geographic concepts. I already know and understand the concepts of latitude and longitude. What I am trying to find is the angle between two points having those points data. First I ...
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### Viewing Angle Effect On Spectral Reflectance Sentinel-2

I am new to remote sensing and would like resources and literature explaining the effect of viewing angle on spectral reflectance for satellites. I have read the study by Moriya et al translated to ...
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### Adjusting angles after drawing polygon in ArcMap

I need to adjust the angles of a polygon that I've drawn in the ArcMap environment. In fact, I've converted the polyline to polygon by using data management tools and features. Now I want to modify ...
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### Add angle of point from road as seen from left to right?

I have a layer of trees (purple points) that I want to add a column that equals the order of trees by angle if seen from left to right. For example, with the property with three trees, you would stand ...
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1 vote
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### Converting aspect/direction raster from geographic degrees to arithmetic radians

I have a raster/grid representing e.g. terrain aspect or flow direction, coded in geographic degrees (0-360°, clockwise from the north). I would like to convert it in arithmetic radians (0-2π, ...
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### What is angle value in points along geometry in QGIS?

I generated the points along geometry from Processing toolbox and there is an angle field as default. What does it stand for?
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### Calculate angle between two 3D points [closed]

Given two points with xyz-coordinates, how to find the angle between them as shown in the picture. Is there a tool for it in ArcGIS Pro? I have looked into PointGeometry, but it did not seem to have ...
65 views

### sunAngle() calculation in R giving wrong results

I need to find the hourly sun angle (angle at which the sun strikes the Earth) for a particular position (latitude, longitude) for a given day in Belgium. I used sunAngle() from "oce" ...
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### Calculating the angle of view from points to a polygon

This question Calculate field of view / angle of a point to a shapefile was attempting to achieve a similar outcome to my need (calculating the angle of view between observer locations and a polygon). ...
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1 vote
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### QGIS 3.16 - Angles/Azimuth from advanced Digitizing in attribute table

I have simple question, how can i export angles from Advanced Digitizing Panel do attribute table? . For example , i want to draw a line of length 100m at angle -45 degree. I do it using advanced ...
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### Convert GPS bearing to Cartesian angle

I have two GPS coordinates: Location A 25.07507, 55.14012. Location B 25.07571, 55.13975. The bearing between location A and location B is 332.9°. If we know that location A has a Cartesian point of ...
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### Determining orientation of bay using QGIS

I want to know the orientation (relative to North) of a bay. The idea is, if I draw a line along a coast, and it crosses the bay mouth, I want the direction of the line perpendicular to that line (as ...
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1 vote
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### Calculating angles of vector polylines

I would like to calculate the angles of my vector polylines (and later use this value to colour them, so all the similarly angled lines (i.e. that have the same orientation / have the same colours). ...
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### Measure an angle on an orthophoto or on a dense cloud

I'm currently working on QGIS 3..10.1, and I would to analyse my roof with UAV analysis. I have already made a dense cloud, an orthophoto and a DEM on agisoft metashape but now I would make few ...
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### Angle of lines between two points varies between "90" and 270"

I have several sets of points on a layer, with all sets of points in nearly the same geographic location. I use the "points to paths" function and then explode the lines. I then use the ...
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### Calculating interior angles of polygons or lines in QGIS

The problem In QGIS, it's easy to calculate areas of polygons or lengths of lines using QGIS expressions with area (\$geometry) / \$area or length(\$geoemtry) / \$length respectively. However, there is no ...
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### Simplifying polygon by inner angle in QGIS

I'm trying to simplify a polygon using the interior angle of a vertex as the "tolerance" instead of the distance between vertexes. For e.g. the polygon in the image below would lose one ...
1 vote
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### Calculating azimuth angle from two X,Y,Z points

I'm following @whuber's post for calculating azimuth and elevation angles based on two vector3's. The elevation equation works great and gives me numbers that makes sense. I'm running into issues with ...
461 views

### Generalizing line with angle rules in QGIS

I'm looking for an automatic way to generalize/simplify vector lines in QGIS like the following picture : I would like the generalization to include only the angles indicated by the small star on the ...
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### Calculating average slope and compass point of polygons in QGIS 3.18

I am using QGIS to rank about 800 PV areas according to their potential. I have a vector (.shp) layer with certain areas in polygons (inc. attribute table, every polygon has it's own ID). Now I would ...
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### Angle from x axis with QGIS

I am using QGIS 3.10. I am trying to make an angle of line from x-axis in 0-180 range. This picture shows what I'm trying to do. I want green lines to have angle of 140 for the upper one and -52 for ...
1 vote
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### Display angle of each line feature within a specific field for that layer using UpdateCursor method

So I want to calculate angles for each line feature layer using UpdateCursor method. So far I have progressed with the code but what it is doing is; it is giving the result of the last feature angle ...
81 views

### Plotting polygon on map with length of sides known and lat lng known only for two vertices and no angles known

I have an image(a polygon), generated by survey department from a field survey. I know the lat lng of two vertices and the length of all sides.I do not know the size of the angles.(Using a protractor ...
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### Calculating dominant angle of a polygon in QGIS without main_angle function

How can I calculate dominant angle of a polygon in QGIS without main_angle function? I have a shapefile of Oriented Minimum Bounding Box rectangles (accessible from the following link: https://drive....
• 537
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### Finding interior angles of a triangle using PyQGIS

I need interior angles of a triangle (QgsTriangle object). It has angles() method. There is an example in documentation. But sometimes the method doesn't give correct results I expect. For example: ...
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### Resizing rectangle by dragging one side and retaining all right angles using QGIS

I cannot resize a rectangle polygon feature in QGIS in a way that retains right angles on all the vertices. There does seem to be an “intent” for this capability to exist via the “snap to common angle”...
1 vote
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### R statspat package (or similar pkg) and convert back to spatial objects

I've been testing the waters and doing some basic overview on the statspat package. This is a complex package and would likely require some serious effort to jump in and then get familiar with the ...
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1 vote
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### Calculate angle of view from a point based on DEM using QGIS

I'm looking for a way to calculate the angle of view from a point on a DEM, in particular from the highest point of a terrain relief (corresponding to the red dot in this image below). To better ...
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### Calculating midpoint between every two closest points using ArcGIS Pro

I am looking to try and identify the midpoint between two closest points in my layer in ArcGIS Pro. The reason being that I work in the utilities industry and I am trying to calculate the angle ...
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### Setting vertical scan angles in visibility analysis (viewshed) using QGIS

Is it possible, doing a visibility analysis (viewshed) in QGIS, to set a vertical angle of search from the observer points? In ArcGIS Pro viewshed, there are the vertical upper angle and vertical ...
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1 vote
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### Compute elevation and azimuth from lat, lon, and altitude

Given the latitude, longitude and altitude of two points (in my case satellite and ground antenna) I would like to compute the azimuth and elevation angle between the two points from the ground ...
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### What does the "bisector angle of vertex for original geometry" mean in the Extract Vertices tool?

I need to calculate the number of notches in my polygons. Therefore I need to know the angles of the vertices in a set polygons. I managed to extract a value for the angle by the Extract Vertices tool ...
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### Gradians to degrees with zero

I want rotate symbol, but the angle is in gradians (grade, gon) with zero on east. How to convert this angle to degrees with zero on north ? I try (angle*0.9 + 90), but e.g. for angle with 380 gon => ...
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### How can I calculate the course angle of two coordinates in decimal degrees?

I want to calculate course angle of two given decimal degrees, like shown in the following picture: In the above picture the result would be 135° The coordinates are given in decimal degrees, e.g. (...
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1 vote