[R] Help with R

[Duncan Murdoch]

On 19/11/2016 1:32 PM, Jackson Hooten wrote:
> Hello R Help,
>
> I am fairly new to R and have been scouring the internet trying to find
> useful tips, tricks and advice with how to solve my problems with R. I
> finally was able to find you guys, and am now asking for your help.

You can find a fairly recently edited discussion of how to get help at

https://www.r-project.org/help.html




I have
> a number of different questions regarding R. My most pressing question is,
> how does one get a map of a very specific area into R? I've been following
> a tutorial that one of my teachers sent me and been following his code.
> However, every time I input this code I get a warning message:
>
> My teacher's code:
>> plot(map, col="dimgray", border=F, add=T)
>
> The Error code I get every time I input the above code:
>> Error in plot.window(...) : need finite 'ylim' values
> In addition: Warning messages:
> 1: In xy.coords(x, y, xlabel, ylabel, log) : NAs introduced by coercion
> 2: In min(x) : no non-missing arguments to min; returning Inf
> 3: In max(x) : no non-missing arguments to max; returning -Inf
> 4: In plot.window(...) : "border" is not a graphical parameter
> 5: In plot.window(...) : "add" is not a graphical parameter
>
> So, what I think I figured out was that I didn't possess the "map" that my
> teacher had in his R program. So I went to try and figure out how to get my
> own map into my R session. I found this line of code to try and input a
> good Google Earth map I found that I need for my study. But, alas, this
> code didn't work either and I got more Error codes.
>
> The code I used:
>> img <-readPNG(system.file("img", "Seal_Island_Map.png", package="png"))
>
> The Error code I get every time I input the above code:
>> Error in readPNG(system.file("img", "Seal_Island_Map.png",
> package="png")) : unable to open
>
>
> For the life of me, I have not been able to find anything anywhere that can
> help me solve these problems. What am I doing wrong? Can you all help?
> Thank you and I hope to talk to you all soon.

You need to tell R where the "Seal_Island_Map.png" file is sitting.  The 
"system.file(...)" call you used says it's a file in the "png" package, 
but it's not.  The easiest way to find a file is to use the 
file.choose() function to open a file selection dialog, e.g.

filename <- file.choose()
readPNG(filename)

Duncan Murdoch