CONTOUR_WORLD Name
CONTOUR_WORLD Purpose
This procedure draws a colour contour of a data field over a world map.
Category
Graphics
Calling Sequence
contour_world, Data, Lon, Lat Inputs
Data: The data field array in [longitude,latitude] format, or a vector of
[space] format. Of type integer or floating point.
Lon: A vector of the longitude coordinates of the data array, of type
integer or floating point. Of format [longitude] or [space],
depending on the format of Data.
Lat: A vector of the latitude coordinates of the data array, of type
integer or floating point. Of format [longitude] or [space],
depending on the format of Data.
Keyword Parameters
ARROWEND: If set, then pointed end levels are plotted, indicating that
the end levels extend beyond the range of the plot. The default is
rectangular end levels, like all the other levels. A 2 element vector
can also be input, where the first element gives the setting (0 or 1)
for the left/bottom end and the second for the right/top end.
AXIS: If set axis labels are printed. This only works with the
cylindrical projection at the moment.
BOLD: If set then text is written in bold font, if set to zero then
regular font is used. The default is to be set.
BLOCKCELL: If set then cells in a regular grid are filled with blocks.
The default is to use IDL's interpolating contour procedure. This is
automatically set to 0 if irregularly gridded data has been input,
i.e. if Data is a vector.
C_COLORS: A vector of colour indices for the contoured levels. The
default may not look great with certain colour tables.
CENTRE: The coordinates of the central point of the plot, of format
[longitude,latitude].
CHARCOLOR: The colour index of the map title and border, and the legend
title and border. The default is set in !P.COLOR.
CHARSIZE: The size of the text characters. The default is 1.
CLIP: If set to 0 then no clipping is performed. See map_set for more
information.
COASTS: If set, coastlines, islands, and lakes are drawn.
COLOR: The colour index of the continent outlines. The default is set in
!P.COLOR.
COUNTRIES: If set, national borders are drawn.
FONT: An integer specifying the graphics font to use. The default is
Helvetica bold.
HIRES: If set, a high resolution map of boundaries is used.
HORIZON: If set then a horizon is draw, if the projection permits. See
map_set for more information.
LEGEND: If set, the procedure plots a colour legend at the bottom of the
window. The default is no legend. This can also be a 2-element
vector containing the position ([x,y]) in normal coordinates of the
lower left corner of the legend box.
LEVELS: A vector of values for the contour levels. This can be
determined automatically from the data.
LIMIT: A four-element vector specifying the limiting coordinates of the
mapping area, in the format of [minlat,minlon,maxlat,maxlon].
NOERASE: If set, the procedure does not erase the screen before
plotting. The default is to erase before plotting.
NOBORDER: If set, then no window border line is drawn. The default is to
draw a border.
NOLINES: If set, then no outlines are drawn. The default is not set.
NTICKS: The number of ticks and labels to be used in the legend. This
can be determined automatically.
OUTLINE_COLOR: The colour index of the OUTLINE_DATA contour lines. The
default is COLOR.
OUTLINE_DATA: An optional data array of the same size as Data. Contour
lines for OUTLINE_DATA are plotted on top of the colour-contours of
Data.
OUTLINE_LEVELS: Like LEVELS but corresponding to OUTLINE_DATA. The
default is LEVELS.
OUTLINE_POINT: If contour lines are being drawn, then setting this
keyword causes perpendicular ticks to be drawn on the contours lines.
If set to -1 then the ticks point downhill on OUTLINE_DATA, if set to
1 then they point uphill. The 1 setting does not work of BLOCKCELL=0.
[X,Y]RANGE: A 2-element vector containing the minimum and maximum
[x,y]-coordinates to be plotted.
REGION: Obsolete keyword retained for continuity.
RIVERS: If set rivers are drawn.
THICK: The line thickness used for drawing.
[X,Y]THICK: The line thickness used for drawing the axes. This only
works if the AXIS keyword is set.
TICKNAME: A vector of strings to place on the tick marks in the legend.
This can be determined automatically.
TITLE: A string containing the title of the plot.
[X,Y]TITLE: A string containing the title of the [X,Y] axis. This only
works if the AXIS keyword is set.
UNITS: A string containing the title or units subtitle for the legend.
WRAP: If set, the plot connects the westernmost and eastermost points to
produce a continuous plot. The default is to do this only if the data
appears global in longitude.
CYLINDRICAL: If set a cylindrical projection is used. This is the
default.
MERCATOR: If set a Mercator projection is used.
NORTH: If set an orthographic projection is used, centred on the North
Pole and covering the Northern Hemisphere.
ORTHOGRAPHIC: If set an orthographic projection is used.
SATELLITE: If set a satellite projection is used. See map_set for more
information.
SAT_P: Input vector required if SATELLITE is set. See map_set for more
information.
SOUTH: If set an orthographic projection is used, centred on the South
Pole and covering the Southern Hemisphere.
Uses
choose_levels.pro
contour_legend.pro
dimension.pro
odd.pro
sign.pro Procedure
This procedure plots a world map using map_set.pro and map_continents.pro
and then plots a colour contour on top using contour.pro.
Example
Contour an increasing-value 20*10 array over a map of Earth.
arr = findgen(20,10)
loadct, 5
contour_world, arr Modification History
Written by: Daithi A. Stone (stoned@atm.ox.ac.uk), 2000-09-21.
Modified: DAS, 2000-09-28 (level-picking stuff).
Modified: DAS, 2000-11-16 (fixed polar projection bug).
Modified: DAS, 2000-11-29 (added NTICKS and TICKNAME keywords).
Modified: DAS, 2001-04-11 (added ability to handle irregular data).
Modified: DAS, 2001-05-16 (added REGION, WRAP, LIMIT keywords).
Modified: DAS, 2002-04-10 (switched STD.pro to STDDEV.pro)
Modified: DAS, 2004-10-26 (improved documentation; added AXIS, COASTS,
COUNTRIES, HIRES, RIVERS, THICK, [X,Y]THICK keywords)
Modified: DAS, 2006-02-14 (added BLOCKCELL keyword; removed some WRAP
value selection stuff; made REGION option automatic and therefore
obsolete)
Modified: DAS, 2008-03-14 (fixed bug with LIMIT keyword wrapping
longitude when BLOCKCELL set)
Modified: DAS, 2009-02-12 (added NOLINES keyword)
Modified: DAS, 2009-09-02 (fixed bug using coordinate ordering with
irregular data; added use of BLOCKCELL with irregular data; ensured
LEGEND option does not overwrite map plotting coordinates)
Modified: DAS, 2009-11-09 (added BOLD keyword)
Modified: DAS, 2009-12-08 (added ARROWEND keyword)
Modified: DAS, 2009-12-09 (added fix to ensure longitudes do not span
more than 360 degrees)
Modified: DAS, 2009-12-15 (fixed bug in dealing with values outside the
range of LEVELS)
Modified: DAS, 2009-12-23 (added OUTLINE contour feature)
Modified: DAS, 2010-01-06 (added OUTLINE_POINT keyword; editted format;
fixed OUTLINE_COLOR bug)
Modified: DAS, 2010-05-02 (fixed bug in OUTLINE with non-monotonic
coordinates)
Modified: DAS, 2010-05-21 (fixed bug with shifting !p.multi values after
call to contour_legend.pro; added modification to CHARSIZE in
contour_legend.pro if !p.multi is used)
Modified: DAS, 2010-09-16 (added FONT keyword)
Modified: DAS, 2010-11-19 (added CLIP, HORIZON, NOBORDER, SATELLITE,
SAT_P keywords; added OUTLINE_DATA capability when BLOCKCELL=1 and
DATA is irregularly gridded)
Modified: DAS, 2011-03-16 (fixed bug with legend tick labels when
!p.multi=0)