blighty               package:blighty               R Documentation

_B_r_i_t_i_s_h _I_s_l_e_s _C_o_a_s_t_l_i_n_e_s

_D_e_s_c_r_i_p_t_i_o_n:

     Function for drawing the coastlines of the British Isles

_U_s_a_g_e:

     blighty(place, grid=FALSE, xlimits, ylimits, xpadding=0, ypadding=0, parcol, parbor, parwdh, sarcol, sarbor, sarwdh, parang, parden, sarang, sarden, tlncol, tlnwdh, grdcol, grdwdh)

_A_r_g_u_m_e_n_t_s:

   place: map set - a list of objects to plot - see notes - default -
          '"set.UK"'

    grid: 'TRUE' or 'FALSE' - places a grid in OS km over the map -
          default - 'FALSE'

 xlimits: vector of limits in OS km in which to draw the map

 ylimits: vector of limits in OS km in which to draw the map

xpadding: kms to leave to either side between the edges and map in the
          _x_ direction - default = 0

ypadding: kms to leave to either side between the edges and map in the
          _y_ direction - default = 0

  parcol: primary area colour - '"transparent"' for no shading -
          default - 'par("bg")'

  parbor: primary area colour - '"transparent"' for invisible - default
          - 'par("fg")'

  parwdh: primary area border width - default 1

  sarcol: secondary area colour - '"transparent"' for no shading -
          default - 'par("bg")'

  sarbor: secondary area colour - '"transparent"' for invisible -
          default - 'par("fg")'

  sarwdh: secondary area border width - default 1

  parang: angle of hatching lines for primary areas - default 'NULL' -
          'parden' must be set to positive if hatching is to appear -
          look at 'polygon' for further information

  parden: density of hatching lines for primary areas in lines per inch
          - default - 'NULL' - 'parden' must be set to positive if
          hatching is to appear - look at 'polygon' for further
          information

  sarang: angle of hatching lines for secondary areas - default 'NULL'
          - 'parden' must be set to positive if hatching is to appear -
          look at 'polygon' for further information

  sarden: density of hatching lines for secondary areas in lines per
          inch - default - 'NULL' - 'parden' must be set to positive if
          hatching is to appear - look at 'polygon' for further
          information

  tlncol: colour of lines for non-area objects - default - 'par{"fg"}'

  tlnwdh: width of lines for non-area objects - default = 1

  grdcol: colour of grid lines - default - 'par{"fg"}'

  grdwdh: width of grid lines - default = 1

_V_a_l_u_e:

     returns the object 'blighty.mapinfo' in the global environment to
     give information for 'north.pointer' and  'map.scale'

_N_o_t_e:

     Inspired by the package 'oz', 'blighty()' draws the coastline of
     many of the British Isles. The output is suitable for general
     purpose illustrations, distribution diagrams; it is not
     heavyweight GIS or meant for calculation in any way.

     The original coordinates were taken from a scan of a map of
     England, Scotland and Wales in my 1936 edition of _The World of
     Wonder_ to avoid any copyright problems. The scan was then
     imported into *xfig* and the coastline and internal boundarys were
     digitised using the polyline function. Each section of coastline
     was then saved as seperate file. A small amount of hand editing of
     each file allows them to be read in as coordinate points in *R*
     (functions availible from the author and in the /misc directory of
     the package). The problem with using such an early work from which
     to take the primary image is that bits which were present then may
     not be now as coastal errosion may have affected the East of
     England.

     The coordinate system was taken from various easily recognisable
     points of the UK coastline. The calculated error on these is in
     100s of metres, the real error from comparison is about 3km.
     Still, most features for which a grid reference from an Ordinance
     Survey map can be plotted on easily.

     Unfortunately _The World of Wonder_ did not include a map of
     Ireland or the Northern Isles, however, the Irish will be
     delighted to know that I got some suitable maps from a tourest
     guide to Ireland which will be incorperated into the next release
     as soon as I can get a grid system to tie Ireland into mainland
     Britain. For 'blighty_2-0.0' the Orkneys and Shetlands  added.
     They can be displayed using '"set.Scotland.all"'. 

     Don't use the 'xlimits' and 'ylimits' to zoom in too far as the
     point resolution isn't really up to it. There is now a warning for
     this - basically the maps start to look bad at anything less than
     200km.

     It can also take a few seconds when drawing all of the British
     Isles, this is mainly because of the west coast of Scotland and
     Western Isles which because of their shape take up loads of data
     points.

     For 'blighty_2-0.0' the maps have been hand edited to tidy them up
     a lot, the Scilly Isles and Lundy have been added, various
     inconsistencies have been fixed, and the examples changed.

     At the request of numerous people there are now a set of primitive
     tools in the package '\misc' directory to enable people to
     construct and use their own maps. To get this download the source
     'blighty_x.y-z.tar.gz' to a directory, 'tar -zxvf' it, then look
     in the 'blighty_x.y-z.tar.gz/misc' directory - although it is part
     of the distribution it is not installed as such, therefore needs
     manual unpacking.

     New functions which draw scales and North pointers have also been
     added as from 'blighty_2-0.0'.

     Basically blighty is an elborate wrapper for 'polygon' and
     'points' with some data files added. As such it will plot more or
     less any sets of coordinate points - so is by no means restricted
     to the distributed objects. At the moment it has three object
     types (although more can easily be added), one is a primary area -
     used for a landmass, the secondary area is a shaope within the
     landmass, such as a lake, the tertiary feature type is a non-area
     type such as a river. The type of feature is encoded into the data
     files, 'blighty()' then knows how to treat the object.
     Unfortunately secondary area objects will not cut out an area of
     the primary objects - so unless the parent primary area object is
     '"transparent"', the secondary area object can be '"transparent"',
     but it will merely show the primary area colour. It would be good
     to rectify this, but I can see no way at the moment of doing so
     with the present data structure.

     Additional place sets are: '"set.all"', '"set.England"',
     '"set.Wales"', '"set.Scotland"' and '"set.Scotland.all"', although
     it is simple to specify your own - see additional documentation in
     '\misc' directory.

_A_u_t_h_o_r(_s):

     David Lucy <dlucy@maths.ed.ac.uk><URL:
     http://www.maths.ed.ac.uk/~dlucy/>

_S_e_e _A_l_s_o:

     'map.scale' 'north.pointer' 'oz'

_E_x_a_m_p_l_e_s:

     blighty()               # UK coastline
     blighty(grid=TRUE)      # UK coastline with grid
     points(399,91)          # add in Poole OS coords last digit is 1km
     text(400,50,"Poole")

     blighty("set.Scotland") # Scotland and the Western Isles
     points(327, 672)        # OS coords for Authurs Seat
     text(327, 655, "Edinburgh")

     blighty("set.Wales")    # Wales and Anglesey

     blighty("set.England", xlimits=c(400,600), ylimits=c(50, 200))
     box()                   # south of England and the Isle of Wight
                             # and the Thames Estuary

     blighty()               # do a plot then add the capital cities

     x <- c(532, 327, 317)   # make up two vectors of points
     y <- c(181, 672, 175)   # for capital cities

     names <- c("London", "Edinburgh", "Cardiff") # vector of names
      
     points(x,y, col="red")  # add in the points in red
      
     text(x + 20, y, labels=names, adj=0)
                             # add some labels displaced by 20km to the right

     blighty(parcol="gray")  # use a basic shading

     blighty("set.Scotland", parcol="blue", parbor="red", sarcol="red", tlncol="green", tlnwdh=3)
                             # looks hideous but demonstates some of the shading
                             # functions

     blighty(parang=45, parden=30, parbor="transparent", parcol="black", sarbor="transparent", tlncol="transparent")
                             # more of a picture for logos etc

