I am currently trying to generate a map in R demonstrating where my different sampling locations are along the east coast of Canada. I had my code working previously yesterday and was able to visualize the specific area I wanted to look at, and then layer my point on top.
This morning however, when I open the project back up and try to generate the map with this line of code:
map("worldHires", "Canada", xlim=c(-80,-45), ylim=c(40,60), col="gray90", fill=TRUE)
I get the output [[1]] NULL. This is not trying to plot the sampling locations yet, just generating a blank map which I will plot the points over. All the necessary packages (to my knowledge) are loaded (maps, mapdata, maptools, scales) and I don't understand why it was working fine yesterday but today I am only getting this output. I have tried with other regions as well and no matter what I put into the argument it only returns NULL.
I have also tried just entering the line:
map("world", xlim=c(-80,-45), ylim=c(40,60), interior=TRUE)
However when I do this I get this error: Error in as_mapper(.f, ...) : argument ".f" is missing, with no default (which makes sense to me given that this line of code seems to be missing the argument of where it is drawing the geographical data from)
Any tips on what to do? I don't understand why it would be returning a NULL result and I haven't been able to find much help online so far.
Related
Is there a way to (or what is the best way to) plot a map of a specific city, along with roads or neighborhood outlines?
I am pretty new to using R, so I've done a bit of Googling for an answer, but the ones I come up with don't work too well:
With ggmap, it appears I'd have to pay to get a good map. This is probably fine for me, but I'd be curious to see if there's a free way, such as with the maps package. I tried mapping a city (Minneapolis) with the maps package, but it came back with an error which I can't figure out how to get rid of, either through experimenting or Googling for help. Below is the code I did:
Minnesota <- subset(states, region %in% c("minnesota"))
which just kept coming back with Error: object 'states' not found. This was my first attempt to bring up a map of which I could zoom in on using the maps package. Does this mean maps didn't install correctly? Or is there something I'm missing?
I also tried using map, which I believe is part of ggplot2, with the code below:
map(database = "state", xlim = c(-93.0, -94.0), ylim = c(44.5, 45.5))
Again, this was to try and get a zoomed in map of a particular city, Minneapolis, but I kept getting the error "all data out of bounds". I assumed this was because the coordinates I entered were incorrect, but they line up with the coordinates of the city. What does it mean that all data is out of bounds?
The last thing I tried was using the package rworldmap. With the code below:
minneapolis <- getMap(resolution = "low")
plot(minneapolis, xlim = c(-93, -94), ylim = c(44.5, 45.5))
I think this one was actually working, the problem is that it's so zoomed in that I can't see the borders that come with the package/plot. Would there be a way to add roads/neighborhood borders to a map like this one? It seems like that would be the best way for me to build a map for free, but maybe I'm wrong.
Thank you for any help and clarification.
If you want the map to be interactive, then you should consider using leaflet, You can check this tutorial.
If you want it to be static ggmap or tmap are good options.
You do no need to pay. You can access the goole api or the OSM api and get the data.
Similar to this question:
Plotting UK postcodes on a map in R
I am trying to plot various postcodes on a map using the plotGoogleMaps function, however when I get to the last step e.g.
m <- plotGoogleMaps(UK_Map , filename='MAP_UK.html')
Nothing happens except for the little stop sign in the corner appearing as if something is loading.
Is anyone able to tell me how I can view the map / where I'm going wrong? I have read elsewhere that you can supposedly view the file in your working directory but unfortunately it's not there so I'm not sure what to do.
Below is a JavaScript page I have created that allows me add and freely move markers on the map. From this map I can figure out the regions I am interested in.
Basically what I want to do is show the same map using ggplot2/MarMap with coastline indicators + bathymetry data. I am really just interested in getting bathymetry data per GPS location, basically getting negative/positive elevation per Lat+Long, so I was thinking if I can plot it then I should be able to export data to a Database. I am also interested in coastline data, so I want to know how close I am (Lat/Long) to coastline, so with plot data I was also going to augment in DB.
Here is the R script that I am using:
library(marmap);
library(ggplot2);
a_lon1 = -79.89836596313478;
a_lon2 = -79.97179329675288;
a_lat1 = 32.76506070891712;
a_lat2 = 32.803624214389615;
dat <- getNOAA.bathy(a_lon1,a_lon2,a_lat1,a_lat2, keep=FALSE);
autoplot(dat, geom=c("r", "c"), colour="white", size=0.1) + scale_fill_etopo();
Here is the output of above R script:
Questions:
Why do both images not match?
In google-maps I am using zoom value 13. How does that translate in ggplot2/MarMap?
Is it possible to zoom in ggplot2/MarMap into a (Lat/Long)-(Lat/Long) region?
Is it possible to plot what I am asking for?
I don't know how you got this result. When I use your script, I get an error since the area your are trying to fetch from the ETOPO1 database using getNOAA.bathy() is too small. However, adding resolution=1 (this gives the highest possible resolution for the ETOPO1 database), here is what I get:
To answer your questions:
Why do both images not match?
Probably because getNOAA.bathy() returned an error and the object dat you're using has been created before, using another set of coordinates
In google-maps I am using zoom value 13. How does that translate in ggplot2/MarMap?
I have no clue!
Is it possible to zoom in ggplot2/MarMap into a (Lat/Long)-(Lat/Long) region?
I urge you to take a look at section 4 of the marmap-DataAnalysis vignette. This section is dedicated to working with big files. You will find there that you can zoom in any area of a bathy object by using (for instance) the subsetBathy() function that will allow you to click on a map to define the desired area
Is it possible to plot what I am asking for? Yes, but it would be much easier to use base graphics and not ggplot2. Once again, you should read the package vignettes.
Finally, regarding the coastline data, you can use the dist2isobath() function to compute the distance between any gps point and any isobath, including the coastline. Guess where you can learn more about this function and how to use it...
I'm simply trying to visualize some land polygons from natural earth
landData2<-readOGR("/home/pavel/Documents/Studium/Hiwi/Maps/ne_10m_land", "ne_10m_land")
landGG2<- fortify(landData2)
after the second line I get the message
"Regions defined for each Polygons"
I already fortified it so this post was of no use
Why does ggplot give a blank page with the message "Regions defined for each Polygons"?
I got the data from
http://www.naturalearthdata.com/downloads/10m-physical-vectors/
I used the simple (not scale ranked) polygons
Does anyone know what it means?
Ok, this went fast.
Following this Post
Filling polygons of a map using GGplot in R
the problem seems to be that fortify does not transfer the id to a numeric variable
simply adding
landGG$id <-as.numeric(landGG$id)
helps
Still not sure why exactly this message comes out and why it is only true for the parts of the data frame after the "hole" variable (id, piece and group variable) but probably some problem with fortify
But it works.
Thought I'd leave it here instead of deleting
I am plotting 2 maps side by side in lattice using an spplot command, using the simple default choropleth style color fill in sp. The syntax I am using is identical to this example:
library(sp)
library(rgdal)
library(lattice)
spplot(nc, c("SID74", "SID79"), names.attr = c("1974","1979"),
colorkey=list(space="bottom"), scales = list(draw = TRUE),
main = "SIDS (sudden infant death syndrome) in North Carolina",
sp.layout = list(arrow), as.table = TRUE)
The maps plot perfectly and exactly as intended side by side. However, I get a warning written on top of each of the maps as follows:
'Error using packet 1 length must be a 'unit' object'(on chart 1)
'Error using packet 2 length must be a 'unit' object' (on chart 2)
I apologize that I cannot give the data here to help troubleshoot. However, I was hoping someone might be able to point me in the right direction of figuring out what is going wrong.
Note: both maps chart perfectly fine as individual maps using the equivalent of:
spplot(nc,"SID74")
Clearly the problem is with the lattice view, but I am not familiar enough (despite having tried to look in Sarkar ch8) with packets to be able to know what is going wrong.
As an alternative, given that my charts are mapping as required, is there a way simply to turn off these warnings?
Many thanks for any help
http://rspatial.r-forge.r-project.org/gallery/#fig09.R gives the commands that reproduce your case. For me, with sp 1.1-1, everything works fine - I get the exact example figure.
If you did something with these data that causes this to malfunction, please report what you did, without that your question is misplaced.