Questions tagged [geography]
Questions on the application of Mathematica to geography, including the use of the CountryData and CityData functions. Not to be confused with geodesy.
271
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Remove islands from geographic regions
I wish to get only the continental parts of countries when using GeoGraphics, for instance in
...
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3
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2
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100
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Solve for subset of parameters in ParametricPlot
I have a discretized region $\mathscr{R}$ and two functions $x(u,v)$ and $y(u,v)$. I wish to find (numerically of course) the values of $(u,v)$ such that
$$
\begin{align}
\left(x(u,v),y(u,v)\right)\in ...
- 555
2
votes
1
answer
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Define functions on Geographic regions
Let's plot a parametric function $(x_s(u,v), \:y_s(u,v))$ on some $uv$ domain as shown below with an annulus as example.
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- 555
2
votes
0
answers
47
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Crop or mask geographics
I am trying to crop a map drawn with GeoGraphics. The map consists of Line and Polygon ...
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2
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Location of the point on Earth with the Sun at the zenith
This should be an easy question, but I don't know the correct syntax.
I'm trying to create an animation based on NightHemisphere during a year. For each day, the instant correspond to the time of the ...
3
votes
1
answer
72
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How to find all coastal cities globally using the Entity framework?
It seems to be an easy task as all the related functions GeoNearest and EntityList["City"] are close at hands.
However,...
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How to find the distances to all buildings quickly?
I would like to create an association by mapping the function GeoDistance[Here,#]& over all buildings without missing locations in a reasonable amount of time less than 30 minutes.
I have the ...
- 1,057
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77
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Why does Entity Class return an empty value sometimes?
I am working on computing the 20 largest cities in California.
...
- 1,057
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2
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58
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How to extract entities from TravelDirectionsData?
I am wondering how to extract entities such as states and cities from TravelDistanceData.
For example, given the following example from the documentation, how could I extract the states the route goes ...
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1
answer
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How to disable legends in GeoListPlot and other geographic functions? [closed]
How can I hide or disable the automatic legend feature of GeoListPlot?
I have the following code and results:
...
- 1,057
4
votes
0
answers
62
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Accelerate the retrieval time for Entity data
I like to use Mathematica to answer questions related to cities such as how many cities in the United States have a population greater than 100,000 and what the distribution of them would look like on ...
- 1,057
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How to find N most populous cities in each state with TakeLargest and Entity Functions without waiting forever using Caching?
I am interested in using Entity Functions such as EntityValue, FilteredEntityClass, EntityFunction, EntityClass, EntityList, and GeoEntities to help me find N most populous cities in each state. I ...
- 1,057
3
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0
answers
82
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Calculate the nth percentile height above sea level of a country or US State
Mathematica has access to geographic height data for different territories. This can be used to plot sea level rise maps. However I am interested in what percentage of the area of a country or state ...
- 206
3
votes
1
answer
72
views
How to use `Quantity` to convert Degrees of Latitude into Kilometers?
I want to convert 0.018 Degrees of Latitude into kilometers using the Quantity function in Mathematica. Unfortunately I do not know what Degrees of Latitude are ...
- 6,959
3
votes
1
answer
114
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How Color the PathGraph Showing Multiple Shortest Paths on the US Counties Map
Below is code for mapping the connectivity of US counties. It comes from the Mathematica reference on "Connectivity of US Counties". I've highlighted 3 shortest paths shown in red. However, ...
- 1,039
4
votes
1
answer
157
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Plot a Map of German Bundesländer with specified colors assigned to them
I would like to draw a map of the German states ("Bundesländer") with Mathematica 12.
I found examples how to outline countries. But I need the next smaller levels.
I have not found anything ...
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3
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1
answer
108
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Is it possible to get a graph for Taiwan water area
I tried to get a graph for water area in Taiwan, but somehow it doesn't seem to work:
...
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2
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1
answer
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Can a ListPointPlot3D be overlayed with map
I am trying to make a graph of earthquakes (position and depth) shown on map of the country. The map is drawn with Graphics3D option with the code:
...
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vote
1
answer
92
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How to output Polygon with latitude and longitude set in EntityValue function?
I used EntityValue to represent a map of a country.
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12
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4
answers
2k
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How can we find the longitude that cuts all the land on Earth in half?
Mathematica has already a specific function, RegionCentroid, that can be utilized to calculate the geographic center of any region. As it has been discussed in here ...
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4
votes
1
answer
94
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How to show net income geographically of a company in a certain city
Let's say that I have a company, and I already extracted it's net profit with time series.
...
- 241
14
votes
1
answer
1k
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Are Mathematica's maps copyright-free?
Are the maps available in Mathematica copyright-free? For instance, if I generate the image
...
- 4,228
0
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1
answer
44
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How to prevent small locations from being plotted as points when using GeoListPlot?
When a location is too small, GeoListPlot marks that location using a point on the map. For example,
...
- 57
5
votes
1
answer
92
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Improving performace of `GeoDistance` and `NearestNeighborGraph`
I am trying to construct a NearestNeighborGraph of the 3143 US counties, using their latitude and longitude positions.
...
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4
votes
1
answer
78
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mapping a digraph across sectors of countries
Given a (9,9) matrix representing three countries (for example, the US, China, Russia), each one of which has three sectors (vertices/sectors {1, 2, 3) for the US; {4, 5, 6} for China; and {7,8,9} for ...
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90
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OceanData not deep enough or just too deep for me?
It's exciting to see Mathematica/Wolfram Alpha addressing the marine realm in Version 12.2. Evidently, I was unaware that such data existed since Version 12.0 introduced in 2019. However, I have two ...
- 1,496
3
votes
1
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72
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How to determine population from a list of arbitrary jurisdictions (cities, states, counties, et al.)?
I am an aspiring data scientist who's working on a passion project, namely to assign danger-level scores to police departments in the United States.
One specific metric I'm developing results from ...
- 31
2
votes
0
answers
67
views
Where can you get by walking half a mile?
I recently saw that Mathematica 10 introduced really nice tools for geography. I would like to use GeoGraphics to visualize all possible paths with a length of half ...
- 1,114
14
votes
3
answers
4k
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Oak Island, extending the "Alignment", possible Great Circle?
During these days of COVID, I indulged in the guilty pleasure of watching The Curse of Oak Island - Season 8, Episode 4 Alignment, which viewed last night (1 Dec 2020).
During the episode, some "...
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0
votes
2
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180
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Get coordinates of the boundary of a continent
I'm trying to obtain the coordinates of the border of the continents. I need this information to be ordered such that when I do, for example,
ListLinePlot[data]
It ...
2
votes
0
answers
30
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Difficulty with getting local GeoPosition correctly
I am using the wolfram cloud on a Chromebook and when I type the function Here it returns a faulty ...
- 1,063
0
votes
0
answers
41
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Shifting GeoRange depending on Projection Problem
It's been rather smooth progress lately using GeoGraphics as I attempt to render different polygons over the greater metropolitan Vancouver area. I found this ...
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4
votes
1
answer
104
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Heatmap, visualizing on negative/positive values with Cartography
I want to create a heatmap in relation with a CityMap.
A example of my dataset is:
...
- 2,371
2
votes
1
answer
179
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3D Plot of mountain elevation on a map
I am trying to plot mountains' elevation on a map. Right now, I have a 2D image generated using the code as shown below. I hope to create a 3D plot, on which, at z=0 is the map, and at each coordinate ...
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0
votes
1
answer
51
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GeoGraph based on (x,y)-coordinates
To create a Geograph we use a longitude and latitude to visualize the exact positions. I work with a database without the lon/lat. Instead of that, my database has a X and Y coordinate. I know, there ...
- 2,371
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vote
1
answer
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GeoRegionValuePlot Leaving Out Metropolitan Census Tracts
Preamble
Run this code in the preamble for a working example of what I'm dealing with.
Census Tract Entity Store
...
- 299
3
votes
1
answer
54
views
States surrounding/adjacent to a given state
I want a function that gives a list of all states adjacent to a given state. How can I do this in Mathematica?
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vote
2
answers
284
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How to compute a list of cities within a given radius of another city?
I have hitherto found a solution to this problem.
Designate a city in the continental USA as cityCenter.
Make a table with all large cities in the USA. I could ...
- 365
2
votes
1
answer
82
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Is there any way to speed up many instance of TravelDistance
The goal of this code is to identify and graph a "circle of cities" about a center city.
...
- 365
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1
answer
65
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2
votes
1
answer
193
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How to draw line parallel to the coast on a world map?
The task is to draw a line parallel to the coast 150 nautical miles to the sea, highlighting the ocean between the coast and the line drawn.
An expected result is an image (most aesthetically pleasing)...
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3
votes
2
answers
126
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Using Geo commands, how do I get a list of cities that all meet the following criteria
I am looking to list with Geo commands all the cities such that
Point is 333 miles from Houston
Point is 755 miles from San Antonio
Point is 460 miles from El Paso.
How do I write up the code that ...
- 365
3
votes
1
answer
65
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EntityClass Downloading Speedup
Running this command. Trying to get all cities more than 1 million people in US.
...
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4
votes
2
answers
104
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How to plot countries with accurate area?
Are there any projections that use the true size of countries, like this?
- 30.4k
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0
answers
43
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Use Wolfram Cloud to Create Site Visitor Database
Question: Is there a way to use Wolfram Cloud to create a web API function that, when pinged, does the following:
Gets the geographical location of the user (as an Wolfram entity, like ...
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4
votes
1
answer
138
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Distance between two cities
I need help calculating the distance between 2 cities in Wolfram MAthematica. I would need to create two drop-down lists of European capitals. After selecting any two cities from the lists, I would ...
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0
answers
131
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How to smoothly zoom into GeoGraphics without label flicker?
I would like to animate zooming into maps in a smooth fashion while showing labels - but without them flickering or jumping:
...
- 30.4k
0
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78
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Simpler closed form for spherical coordinates of points on great circle?
Short version: how to simplify this expression given these conditions? Note that expr[[3]] is equal to 1, although Mathematica won't simplify it as such.
...
user1722
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How to get 3D building data in map functions?
Most modern mapping APIs have 3D model data for city buildings built-in. For example:
Is there some way to get this functionality in the Geography related functions?
I believe ...
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4
votes
0
answers
67
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Cloud Deploy dynamic country selection from a map
This is a follow-up question based on the answer I got from Lukas Lang. The original question is here. How can I alter the code to deploy it on the cloud? Or in case this method is only for desktop: ...
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