[R] Midpoint between coordinates

Dear R users, I need to find the coordinates for the point (midpoint) located half way between two pairs of coordinates (lon1,lat1 and lon2,lat2) assuming a straight line between them. What would be the best way? I tried to find an answer in the help archives but without success. I would greatly

Re: [R] Midpoint between coordinates

. Thank you Mafalda On 23 July 2010 13:30, David Winsemius dwinsem...@comcast.net wrote: On Jul 23, 2010, at 7:13 AM, Mafalda Viana wrote: Dear R users, I need to find the coordinates for the point (midpoint) located half way between two pairs of coordinates (lon1,lat1 and lon2,lat2) assuming

Re: [R] Midpoint between coordinates

, 2010, at 8:58 AM, Mafalda Viana wrote: The arithmetic mean was my first approach and to nearby points it doesn't make much difference. However, when the distance between the 2 points gets bigger this is no longer accurate enough. So yes, I was thinking on spherical geometry, midpoint considering

[R] Boxplot with dates

Dear R users, I am having problems making a boxplot across time. I wish to plot the Values (y-axis) against Date (x-axis) but would like the Date to be sequential from 2007-11-15 until 2008-01-31 (therefore there will be lots of NA's e.g. from 2007-11-16 to 2007-11-26 nothing will show in the

[R] Legend in plots

Dear R users, I have what I think it is a very simple question concerning plots in R. If you could help me I would be very grateful. How can I include a legend in my plot? Below I give an example of my data and the code I am using. What I wish to accomplish is a legend saying that the black

[R] barplot2 x-axis

(0,250), xpd=FALSE) Thanking you in advance Mafalda -- Mafalda Viana [[alternative HTML version deleted]] __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org

Re: [R] barplot2 x-axis

, 25, 50...). Hopefully my problem is more clear now, meanwhile I will have a look to your suggestions. Thank you very much Mafalda 2009/3/22 Marc Schwartz marc_schwa...@comcast.net On Mar 22, 2009, at 2:31 PM, Mafalda Viana wrote: Dear R users, I am trying to build a barplot2 graph

[R] split/decompose lines

Dear R users, I have a very simple problem but I can't find the function in R to deal with it. I need to split (or decompose) one line into many lines using one field as a reference. I have a table with the following format: A B Frequency 23 3 2 24 2 5 25 1 3 And need to split

[R] Insert text in data.frame

Dear R-helper, I wonder if anyone can help me. I am trying to convert a dataset to a format recognizable by a software onboard a research vessel but I am having problems with some steps. I have a data frame as follows: Conc Lat LonDepth Point 56.25-5.65

[R] distance between set of coordinates

-- Mafalda Viana Inshore Fisheries Group FRS Marine Laboratory 375 Victoria Road Torry, Aberdeen AB11 9DB UK email: [EMAIL PROTECTED] Phone: +44 (0) 1224 876544 (ext.5684) Fax: +44 (0) 1224 295511 [[alternative HTML version deleted