Network Connection Map in R - r

I want to create a network connection world map in R. I have the longitude and
latitude for one node but I only have the city and state/country for the
other node. Can ggplot or RGoogleMaps still work with this? What should I do?
I am working in Windows.

If you have the city and state/country for the other node, you can get the longitude and latitude using the Googlemaps API in Python. Suppose you have your list of city names in a CSV file, then you can just loop through them one at a time, retrieving the longitude and latitude and writing it to a new file. The results can then be loaded into R as a data frame.
Here is the sample Python code:
from googlemaps import GoogleMaps
import csv
ifile=csv.reader(open('CapitalCities.csv','rb'),delimiter=',')
ofile=open('CapCoordinates.csv','wb')
w=csv.writer(ofile,delimiter=',')
w.writerow(['Name','State','Latitude','Longitude'])
gmaps=GoogleMaps(API_KEY)
count=0
for row in ifile:
if count!=0:
address=str(row[0])+" "+str(row[1])
lat, lng = gmaps.address_to_latlng(address)
w.writerow([str(row[0]),str(row[1]),str(lat),str(lng)])
print row[0],lat,lng
count+=1
ofile.close()
There are also methods for doing the same thing in R. A quick read of this post might prove useful: http://forgetfulfunctor.blogspot.com.au/2012/02/undiscovered-country-tutorial-on.html

Related

Create a Map in Plotly Using Two Files With plot_mapbox

Thanks for reading my post. I am trying to create one map in Plotly using R by layering data from 2 data sources and the function plot_mapbox. The map will show locations of stores in zoned business districts.
test is a geoJSON file of zoning districts
test2 is a csv file of business locations using longitude and latitude coordinates
I've tried layering the data and combining two geoJSON files. The first file is a geoJSON file (business zones)and the second file is a .csv (store locations) with longitude and latitude. I converted the csv file to a geoJSON file and then tried to merge them. I would really need to append them since they don't have a common key.
library(plotly)
library(geojsonR)
library(sf)
test<-st_read("D:/SPB/Zoning_Detailed.geojson", quiet=FALSE, , geometry_column="SHAPE_Area")
test2<-read.csv("D:/SPB/Pet_Bus.csv")
One layering exampe
plot_mapbox(data=test, color=~ZONING) %>%
add_markers(data=test2, x=~Longitude, y=~Latitude)
layout(mapbox=list(style = "streets"))
One merge example (only the first file is added in merge)
files Zoning_Detailed.geojson and Pet_Bus.geojson are in the Merge folder. I
converted Pet_Bus.csv to a geojson file.
This should really be append since test and test2 are independent of each other, but in same city.
merge_files("D:/SPB/Merge/", "D:/SPB/Merge/test7.geojson")

Handling OSM Data for whole country

Is there any way to get the data matching the filters given for the osmdata- library for a whole country or another big part? The problem is if the area is getting bigger, the file is too large and the download aborts. Below is the import section I'm using right now.
library(osmdata)
q <- getbb("Germany") %>%
opq() %>%
add_osm_feature("amenity", "restaurant")
str(q) #query structure
cinema <- osmdata_sf(q)
From the Planet.osm file I can tell you that there are about 97.000 objects, way or node, with tag amenity = "restaurant" in Germany. The OSM-API won't handle that. You'll even get a timeout using overpass-turbo.
For large amounts of data you'll have to download the Planet.osm file into a database. You'll find a nice tutorial here

Geopandas to_file gives blank prj file

I am trying to use GeoPandas for a (only slightly) more complex project, but at the moment I'm failing to write out a simple shapefile with a single point in it in a projected manner.
The following code results in a shapefile that looks generally good - but the .prj is empty:
import pandas as pd
from geopandas import GeoDataFrame
from shapely.geometry import Point
df=pd.read_csv("richmond.csv")
geometry = [Point(xy) for xy in zip(df.x, df.y)]
crs = {'init': 'epsg:4326'}
geo_df = GeoDataFrame(df, crs=crs, geometry=geometry)
geo_df.to_file("geopan.shp")
The csv is 2 row and 2 columns (header row, then lon and lat in 2nd row):
Am I missing something obvious? I've hunted through stackoverflow, the geopandas docs, etc. All seem to imply to_file() should work just fine.
In the long run, the goal is to create a few functions for my students to use in a lab - one that draws a line along a lat or lon the width / height of the US, another that clips the line to polygons (the states), so that the students can figure out the widest spot in each state as a gentle introduction to working with spatial data. I'm trying to avoid arcpy as it's Python 2, and I thought (and think) I was doing the right thing by teaching them the ways of Python 3. I'd like them to be able to debug their methodologies by being able to open the line in Arc though, hence this test.
So, after playing with this, I've determined that under the current version of Anaconda the problem is with crs = {'init': 'epsg:4326'} on Windows machines. This works fine on Macs, but has not worked on any of my or my students' Windows systems. Changing this line to make use of the proj4 string crs = {'proj': 'latlong', 'ellps': 'WGS84', 'datum': 'WGS84', 'no_defs': True} instead works just fine. More of a workaround than an actual solution, but, it seems to consistently work.
I'm always using from_epsg function from fiona library.
>>> from fiona.crs import from_epsg
>>> from_epsg(4326)
{'init': 'epsg:4326', 'no_defs': True}
I've never had any problems using it. Keep it mind that some local projections are missing, but it shouldn't be a problem in your case.
Another user and I had a similar issue using fiona, and the issue for me was the GDAL_DATA environmental variable not being set correctly. To reiterate my answer there: For reference, I'm using Anaconda, the Spyder IDE, Fiona 1.8.4, and Python 3.6.8, and GDAL 2.3.3.
While Anaconda usually sets the GDAL_DATA variable upon entering the virtual environment, using another IDE like Spyder will not preserve it, and thus causes issues where fiona (and I assume Geopandas) can't export the CRS correctly.
You can test this fix by trying to printing out a EPSG to WKT transformation before & after setting the GDAL_DATA variable explictly.
Without setting GDAL_DATA:
import os
print('GDAL_DATA' in os.environ)
from osgeo import osr
srs = osr.SpatialReference() # Declare a new SpatialReference
srs.ImportFromEPSG(3413) # Import the EPSG code into the new object srs
print(srs.ExportToWkt()) # Print the result before transformation to ESRI WKT (prints nothing)
Results in:
False
With setting GDAL_DATA:
import os
os.environ['GDAL_DATA'] = 'D:\\ProgramData\\Anaconda3\\envs\\cfm\\Library\\share\\gdal'
print('GDAL_DATA' in os.environ)
from osgeo import , osr
srs = osr.SpatialReference() # Declare a new SpatialReference
srs.ImportFromEPSG(3413) # Import the EPSG code into the new object srs
print(srs.ExportToWkt()) # Print the result before transformation to ESRI WKT (prints nothing)
Results in:
True
PROJCS["WGS 84 / NSIDC Sea Ice Polar Stereographic North",GEOGCS["WGS 84",DATUM["WGS_1984",SPHEROID["WGS 84",6378137,298.257223563,AUTHORITY["EPSG","7030"]],AUTHORITY["EPSG","6326"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4326"]],PROJECTION["Polar_Stereographic"],PARAMETER["latitude_of_origin",70],PARAMETER["central_meridian",-45],PARAMETER["scale_factor",1],PARAMETER["false_easting",0],PARAMETER["false_northing",0],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["X",EAST],AXIS["Y",NORTH],AUTHORITY["EPSG","3413"]]

Error using fortify() in ggplot2

I am creating a map using the zip code information from the census data together with data that I have for each zip code.
I obtained the shapefiles for the zip codes from https://www.census.gov/geo/maps-data/data/tiger-cart-boundary.html.
I successfully read in the shapefiles using readOGR with the following code:
Zip = readOGR("C:\\...pathname....\\cb_2013_us_zcta510_500k.shp")
I am running into a problem when I try to use fortify so that I can combine the information from the shapefile with my data.
names(Zip)
[1] "ZCTA5CE10" "AFFGEOID10" "GEOID10" "ALAND10" "AWATER10"
test = ggplot2::fortify(Zip, region="AWATER10")
Error in fortify.SpatialPolygonsDataFrame(Zip, region = "AWATER10") :
`region' not supported
The error is replicated when I try all of the results from names(Zip). I am not sure which column contains the zip code information that I am interested in, so I just tried all of them.
My ultimate goal is to use the zip code information with ggmap to fill in the zip codes with different colors based on information in my data.

Creating Shapefiles in R

I'm trying to create a shapefile in R that I will later import to either Fusion Table or some other GIS application.
To start,I imported a blank shapefile containing all the census tracts in Canada. I have attached other data (in tabular format) to the shapefile based on the unique ID of the CTs, and I have mapped my results. At the moment, I only need the ones in Vancouver and I would like to export a shapefile that contains only the Vancouver CTs as well as my newly attached attribute data.
Here is my code (some parts omitted due to privacy reasons):
shape <- readShapePoly('C:/TEST/blank_ct.shp') #Load blank shapefile
shape#data = data.frame(shape#data, data2[match(shape#data$CTUID, data2$CTUID),]) #data2 is my created attributes that I'm attaching to blank file
shape1 <-shape[shape$CMAUID == 933,] #selecting the Vancouver CTs
I've seen other examples using this: writePolyShape to create the shapefile. I tried it, and it worked to an extent. It created the .shp, .dbf, and .shx files. I'm missing the .prj file and I'm not sure how to go about creating it. Are there better methods out there for creating shapefiles?
Any help on this matter would be greatly appreciated.
Use rgdal and writeOGR. rgdal will preserve the projection information
something like
library(rdgal)
shape <- readOGR(dsn = 'C:/TEST', layer = 'blank_ct')
# do your processing
shape#data = data.frame(shape#data, data2[match(shape#data$CTUID, data2$CTUID),]) #data2 is my created attributes that I'm attaching to blank file
shape1 <-shape[shape$CMAUID == 933,]
writeOGR(shape1, dsn = 'C:/TEST', layer ='newstuff', driver = 'ESRI Shapefile')
Note that the dsn is the folder containing the .shp file, and the layer is the name of the shapefile without the .shp extension. It will read (readOGR) and write (writeOGR) all the component files (.dbf, .shp, .prj etc)
Problem solved! Thank you again for those who help!
Here is what I ended up doing:
As Mnel wrote, this line will create the shapefile.
writeOGR(shape1, dsn = 'C:/TEST', layer ='newstuff', driver = 'ESRI Shapefile')
However, when I ran this line, it came back with this error:
Can't convert columns of class: AsIs; column names: ct2,mprop,mlot,mliv
This is because my attribute data was not numeric, but were characters. Luckily, my attribute data is all numbers so I ran transform() to fix this problem.
shape2 <-shape1
shape2#data <- transform(shape1#data, ct2 = as.numeric(ct2),
mprop = as.numeric(mprop),
mlot = as.numeric(mlot),
mliv = as.numeric(mliv))
I tried the writeOGR() command again, but I still didn't get the .prj file that I was looking for. The problem was I didn't specified the coordinate systems for the shapefile when I was importing the file. Since I already know what the coordinate system is, all I had to do was define it when importing.
readShapePoly('C:/TEST/blank_ct.shp',proj4string=CRS("+proj=longlat +datum=WGS84")
After that, I re-ran all the things I wanted to do with the shapefile, and the writeOGR line for exporting. And that's it!

Resources