[R] Adding Two-Headed Arrow in map legend

David Winsemius dwinsemius at comcast.net
Sat Apr 9 19:34:59 CEST 2016


> On Apr 9, 2016, at 8:13 AM, Miluji Sb <milujisb at gmail.com> wrote:
> 
> Forgot to copy the list
> 
> Dear Jim,
> 
> Thank you for your reply. I must be doing something wrong, If this is my
> command to plot a map of Europe:
> 
> eps_europe <- mapCountryData(n, nameColumnToPlot="eps_score", mapTitle="EPS
> Score - Europe",colourPalette=colourPalette,
>                             catMethod="fixedWidth", missingCountryCol =
> "white", mapRegion="Europe", addLegend=FALSE)
> 
> The following command does not seem to add the arrow. What am I doing wrong?
> 
> do.call(addMapLegend, c(eps_europe, legendLabels="none",
> arrows(-100,-140,100,-140,code=3)))
> 

Your earlier question had a full world map. That was the context for Jim's reply, which did plot a two headed arrow above the legend in your earlier question. Now you have restricted the plot region to Europe so the coordinates of -100,-140,100,-140 no longer are on the visible plot area. You need to decide where you want the arrows using sensible coordinates.

-- 
David.


> Thank you again. I really appreciate it.
> 
> Sincerely,
> 
> Milu
> 
> On Sat, Apr 9, 2016 at 12:20 PM, Jim Lemon <drjimlemon at gmail.com> wrote:
> 
>> Hi Miluji,
>> Try this:
>> 
>> arrows(-100,-140,100,-140,code=3)
>> 
>> Jim
>> 
>> 
>> On Fri, Apr 8, 2016 at 10:24 PM, Miluji Sb <milujisb at gmail.com> wrote:
>>> I am trying to draw maps for the world using:
>>> 
>>> library(rworldmap)
>>> library(maptools)
>>> library(RColorBrewer)
>>> 
>>> 
>>> tmp2<- dput(head(pece,10))
>>> structure(list(iso3 = c("AUS", "AUT", "BEL", "CAN", "CHE", "CHL",
>>> "CZE", "DEU", "DNK", "ESP"), eps_score = c(0.877343773841858,
>>> 2.68984365463257, 1.31406247615814, 1.98046875, 2.61666655540466,
>>> NA, 1.44414067268372, 2.34257817268372, 2.89687490463257,
>> 2.15937495231628
>>> ), gov_eff = c(1.76499999562899, 1.85666667421659, 1.74500000476837,
>>> 1.88416666785876, 1.99181815710935, 1.21499997377396, 0.865833342075348,
>>> 1.64999999602636, 2.15416664878527, 1.36833332975705), sh_va_enint =
>>> c(13.4375638961792,
>>> 8.90904521942139, 10.368335723877, 14.0469560623169, NA, NA,
>>> 13.5679216384888, 9.67090892791748, 10.5978908538818, 8.34146690368652
>>> ), rd_in_va = c(2.17547988891602, 2.47147130966187, 2.53955459594727,
>>> 2.01138758659363, NA, NA, 1.49587619304657, 2.72330951690674,
>>> 2.5316367149353, 1.48551619052887)), datalabel = "", time.stamp = " 9 Mar
>>> 2016 17:43", .Names = c("iso3",
>>> "eps_score", "gov_eff", "sh_va_enint", "rd_in_va"), formats = c("%9s",
>>> "%8.0g", "%10.0g", "%9.0g", "%9.0g"), types = c(6L, 254L, 255L,
>>> 254L, 254L), val.labels = c("", "", "", "", ""), var.labels = c("",
>>> "(mean) eps_score", "(mean) gov_eff", "(mean) sh_va_enint", "(mean)
>>> rd_in_va"
>>> ), expansion.fields = list(c("_dta", "ReS_i", "countrycode"),
>>>    c("_dta", "ReS_ver", "v.2"), c("_dta", "ReS_j", "year"),
>>>    c("_dta", "ReS_str", "0"), c("_dta", "ReS_Xij", "a_"), c("_dta",
>>>    "__JVarLab", "ACT"), c("_dta", "__XijVarLabrdd_", "(sum) rdd"
>>>    ), c("_dta", "__XijVarLabp", "Value"), c("_dta", "__XijVarLabpop",
>>>    "Population"), c("_dta", "__XijVarLabest_lu_f", "Source of lu"
>>>    ), c("_dta", "__XijVarLablu", "Percentage of No Schooling"
>>>    ), c("_dta", "__XijVarLabest_lp_f", "Source of lp"), c("_dta",
>>>    "__XijVarLablp", "Percentage of Primary"), c("_dta", "__XijVarLablh",
>>>    "Percentage of Tertiary"), c("_dta", "__XijVarLabest_lh_f",
>>>    "Source of lh"), c("_dta", "__XijVarLabls", "Percentage of Secondary"
>>>    ), c("_dta", "__XijVarLabest_ls_f", "Source of ls"), c("_dta",
>>>    "__XijVarLabvalue", "Value"), c("_dta", "_TStvar", "year"
>>>    ), c("_dta", "_TSpanel", "id2"), c("_dta", "_TSdelta",
>>> "+1.0000000000000X+000"
>>>    ), c("_dta", "_TSitrvl", "1"), c("_dta", "tis", "year"),
>>>    c("_dta", "iis", "id2")), version = 12L, row.names = c("1",
>>> "2", "3", "4", "5", "6", "7", "8", "9", "10"), class = "data.frame")
>>> n <- joinCountryData2Map(pece, joinCode="ISO3", nameJoinColumn="iso3")
>>> n <- n[-which(row.names(n)=='Antarctica'),]
>>> 
>>> # EPS
>>> colourPalette <- rev(brewer.pal(7, "RdYlGn"))
>>> 
>>> eps <- mapCountryData(n, nameColumnToPlot="eps_score", mapTitle="EPS
>>> Score",colourPalette=colourPalette,
>>>                      catMethod="fixedWidth", missingCountryCol =
>> "white",
>>> addLegend=FALSE)
>>> do.call(addMapLegend, c(eps, legendLabels="all", legendWidth=0.5))
>>> 
>>> Instead of adding numeric based legend, I would like to add a two-headed
>>> arrow with some text. I would be grateful for any help. Thank you!
>>> 
>>> Sincerely,
>>> 
>>> Milu
>>> 
>>>        [[alternative HTML version deleted]]
>>> 
>>> ______________________________________________
>>> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
>>> 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.
>> 
> 
> 	[[alternative HTML version deleted]]
> 
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> 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.

David Winsemius
Alameda, CA, USA



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