RES: North Arrow (.png file) on a Map

Another possibility is the my.symbols function in the TeachingDemos package. ?You can define a polygon of your arrow (or other symbol), then use my.symbols to add it to an existing graph, the advantage of my.symbols is that the size of the arrow is absolute, not in terms of the scale of the original plot.

--
Gregory (Greg) L. Snow Ph.D.
Statistical Data Center
Intermountain Healthcare
greg.snow at imail.org
801.408.8111

-----Original Message-----
From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
project.org] On Behalf Of Rodrigo Aluizio
Sent: Wednesday, March 11, 2009 4:22 AM
To: 'Yihui Xie'
Cc: R Help
Subject: [R] RES: North Arrow (.png file) on a Map

Thanks a lot Yihui, It's perfect, in fact exactly identical the I have
as a
png file in my computer.
Thank you so much.

Regards
Rodrigo

-----Mensagem original-----
De: Yihui Xie [mailto:xieyihui at gmail.com]
Enviada em: quarta-feira, 11 de mar?o de 2009 02:48
Para: Rodrigo Aluizio
Cc: R Help
Assunto: Re: [R] North Arrow (.png file) on a Map

Is this "arrow" satisfactory for you?

north.arrow = function(x, y, h) {
? ? polygon(c(x, x, x + h/2), c(y - h, y, y - (1 + sqrt(3)/2) * h),
col = "black", border = NA)
? ? polygon(c(x, x + h/2, x, x - h/2), c(y - h, y - (1 + sqrt(3)/2) *
h, y, y - (1 + sqrt(3)/2) * h))
? ? text(x, y, "N", adj = c(0.5, 0), cex = 4)
}
plot(1, type = "n", ylim = c(0, 1))
north.arrow(1, 0.8, 0.3)

Regards,
Yihui
--
Yihui Xie <xieyihui at gmail.com>
Phone: +86-(0)10-82509086 Fax: +86-(0)10-82509086
Mobile: +86-15810805877
Homepage: http://www.yihui.name
School of Statistics, Room 1037, Mingde Main Building,
Renmin University of China, Beijing, 100872, China



On Tue, Mar 10, 2009 at 7:21 PM, Rodrigo Aluizio <r.aluizio at gmail.com>
wrote:

Hi list.

I would like to know how do I insert a North arrow, stored as a png

file
in

my computer, in a map? I found lots of post asking similar things,

one of

them mentioned the pixmap package. ?The map was done using map() and
shapefiles (the code is below). I'm using the pixmap () and addlogo()
functions. Well I can import the png with pixmap() function (I guess,

once

there's no error message), but I can't put It on the map, I got an

error

message telling me that:



"Error at t(x at index[nrow(x at index):1, , drop = FALSE]) :

?index out of limits"



Well I tried changing coordinates but I always got the same result.

How do
I

do this correctly? Is there a better way?



Thanks for the help and attention.



Here is the complete map script:



library(RODBC)

library(maps)

library(mapdata)

library(maptools)

library(pixmap)

#Carregar Coordenadas e dados dos Pontos Amostrais

Dados<-odbcConnectExcel('Campos.xls',readOnly=T)

Coord<-sqlFetch(Dados,'CoordMed',colnames=F,rownames='Ponto')

odbcClose(Dados)

N<-pixmap('Norte.png',nrow=166,ncol=113)

# Carregar pontos e shapes

Batimetria<-
readShapeSpatial('C:/Users/Rodrigo/Documents/UFPR/Micropaleontol

ogia/Campos/ShapeFiles/Batimetria_BC.shp')

Estados<-
readShapeSpatial('C:/Users/Rodrigo/Documents/UFPR/Micropaleontologi

a/Campos/ShapeFiles/Estados_Sudeste.shp')

Faciologia<-
readShapeSpatial('C:/Users/Rodrigo/Documents/UFPR/Micropaleontol

ogia/Campos/ShapeFiles/Faciologia_BC.shp')

# Mapa com os Pontos da Bacia

postscript('MapaCampos.eps',paper='special',onefile=F,horizontal=F,widt
h=3.5

,height=4.5,bg='white',pointsize=3)

par(mar=c(3,2,2,0))

map('worldHires','brazil',ylim=c(23.9,20.3),xlim=c(42.1,39.2),type='n')

plot(Faciologia,ylab='',xlab='',col=c('lightgreen','lightgreen','lightg
reen'

,'lightgreen','lightgreen','lightgray','lightgray','lightgray','lightgr
ay','

lightgray','lightgray','lightgray','lightgray','lightgray','lightgray',
'ligh

tgray','lightgray','lightgray','lightgray','lightgray','lightgray','lig
htyel

low','lightyellow','lightyellow'),add=T,lwd=0.5,border=0)

plot(Batimetria,ylab='',xlab='',col='darkgray',lty='solid',lwd=0.2,add=
T)

plot(Estados,ylab='',xlab='',lty='solid',add=T,lwd=0.8)

text(Coord$Longitude[Coord$R?plicas=='1'],Coord$Latitude[Coord$R?plicas
=='1'

],rownames(Coord)[Coord$R?plicas=='1'],col='red',cex=0.5,font=2)

text(Coord$Longitude[Coord$R?plicas=='2'],Coord$Latitude[Coord$R?plicas
=='2'

],rownames(Coord)[Coord$R?plicas=='2'],col='yellow',cex=0.5,font=2)

text(Coord$Longitude[Coord$R?plicas=='3'],Coord$Latitude[Coord$R?plicas
=='3'

],rownames(Coord)[Coord$R?plicas=='3'],col='blue',cex=0.5,font=2)

points(Coord$Longitude,Coord$Latitude-0.045,pch=20,cex=0.7)

text(c(41.5,41.3),c(21.7,20.6),c('RJ','ES'))

axis(1,xaxp=c(42.1,39.2,2),cex.axis=1)

axis(2,yaxp=c(23.9,20.3,4),cex.axis=1)

title(main='Bacia')

legend(40.2,23.5,c('Uma','Duas','Tr?s'),pch=21,cex=1,pt.bg=c('red','yel
low',

'blue'),bty='n',pt.cex=2,pt.lwd=0.6,title='R?plicas')

legend(39.8,23.5,c('Areia','Calc?rio','Lama'),pch=21,cex=1,pt.bg=c('lig
htyel

low','lightgray','lightgreen'),bty='n',pt.cex=2,pt.lwd=0.6,title='Facio
logia

')

addlogo(N,px=c(40,39.8),py=c(21,20.8))

dev.off()

q('no')



-------------------------------------------------------------

MSc. Rodrigo Aluizio <mailto:r.aluizio at gmail.com>

Centro de Estudos do Mar/UFPR
Laborat?rio de Micropaleontologia


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