[R] Grid on Map

[Ray Brownrigg]

Have a look at
?mapproject

When you use a projection with map(), you subsequently have to transform your lat/long 
coordinates to conform to the projection.

HTH
Ray Brownrigg

On 8/04/2011 6:11 a.m., Jaimin Dave wrote:
> Hi,
> I tried it using abline but it is not showing any o/p(i.e no grids are
> formed on map). I did following :
>
>   map('state','new york',proj='azequalarea',orient=c(42.5,-74.56,0))
>   abline(h=seq(41, 44, length=3))
>   abline(v=seq(-79, -76, length=3))
>
> I also tried using map.grid() but in some cases it is dividing into exact 4
> quadrants.
>
> On Wed, Apr 6, 2011 at 2:49 PM, MacQueen, Don<macqueen1 at llnl.gov>  wrote:
>
>> Possibly something similar to
>>
>>   abline(v=seq(long.min, long.max, length=3)
>>   abline(h=seq(lat.min, lat.max, length=3)
>>
>> ?
>>
>> The above will add vertical and horizontal lines to an existing plot, and
>> assumes that the plot is in long/lat coordinates. Of course, this ignores
>> the fact that long/lat is not a cartesian coordinate system.
>>
>> (can't provide more detail without more information)
>>
>> -Don
>>
>> --
>> Don MacQueen
>>
>> Lawrence Livermore National Laboratory
>> 7000 East Ave., L-627
>> Livermore, CA 94550
>> 925-423-1062
>>
>>
>>
>>
>>
>> -----Original Message-----
>> From: Jaimin Dave<davejaiminm at gmail.com>
>> Date: Mon, 4 Apr 2011 18:39:45 -0700
>> To: "r-help at r-project.org"<r-help at r-project.org>
>> Subject: [R] Grid on Map
>>
>>> I am new to R.I want to draw grid from a csv file which contains latitude
>>> minimum ,latitude maximum ,longitude minimum ,longitude maximum.The grid
>>> should be divided into exactly 4 quadrants. The map is of NY state of
>>> USA. I
>>> want to know how can I do it.
>>> Help would be appreciated.
>>>
>>> Thanks
>>> Jaimin
>>>
>>>     [[alternative HTML version deleted]]
>>>
>>> ______________________________________________
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>>> and provide commented, minimal, self-contained, reproducible code.
>>
>>
>
> 	[[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.