comp.lang.idl-pvwave archive - RDF feed
type: channel
description: Messages from Usenet group comp.lang.idl-pvwave, compiled by Paulo Penteado
items: Re: PVWAVE and NCAR mapping

Re: PVWAVE and NCAR mapping
type: item
description: In article <LEGLER.91Sep23113234@masig2.masig1.ocean.fsu.edu> legler@masig2.masig1.ocean.fsu.edu (David M. Legler) writes: > > I need some help drawing some geographical outlines on a PVWave plot. > Something like what NCAR graphics can do. For example, lets say a > sample plot of the US outline in black with an overlay of colors > indicating temperatures for a specific month. NCAR has a very nice > geographical map drawing facility and our sales rep says he thinks > others have already written code to use their data base for map > drawing. Is that true, please speak up if so. > > Thanks, > > Mr. David M. Legler ||(904)644-3797 > Mesoscale Air-Sea Interaction ||Arpa legler@masig1.ocean.fsu.edu(128.186.3.1) > Group ||SPAN SCRI1::"legler@masig1.ocean.fsu.edu" > MS B-174 Love-012 ||Bitnet legler%masig1.ocean.fsu.edu@fsuavm > Florida State University || > Tallahassee, FL 32306-3041 || "An Apple II a day, keeps the PC blues away" > BELOW is an IDL map program that I use. It draws a 'pseudo mercator' map: lats/lons are parallel and equidistant. I've included a subroutine that converts lats/lons to Lambert Conformal. In DOMAP are two commented out lines that apply the conversion. The algorithm in words: Find a map data base (I'm assuming you can acquire one). This will probably be divided into 'line segments'...a series of lat/lon pairs that are to be connected 'pen down'. There is also likely to be associated with each line segment the max and min lat/lon for each line segment. This is used to determine whether or not you wish to even consider drawing the line. This data may come separately from the line segements, or may be listed within the segment as if it were the first two points: 43.00 -89.00 41.00 -91.00 42.12 -89.34 41.56 -89.78..... ^^^^^ ^^^^^^ ^^^^^ ^^^^^^ MaxlatMinlonMinlat Maxlon These are your data structures to work with. The DOMAP code looks intimidating because 1) I make the user key in POSITIVE west longitudes, and I jump thru hoops to convert to negativ…
creator: keller
date: 1991-09-24T15:41:47-00:00

Re: PVWAVE and NCAR mapping
type: item
description: legler@masig2.masig1.ocean.fsu.edu (David M. Legler) writes: > I need some help drawing some geographical outlines on a PVWave plot. > For example, lets say a sample plot of the US outline in black ... keller@nsslsun.nssl.uoknor.edu (Dave Keller) writes: > BELOW is an IDL map program that I use. It draws a 'pseudo mercator' > map: lats/lons are parallel and equidistant. > The algorithm in words: Find a map data base (I'm assuming you can > acquire one).... A large data base is available for a few bucks from The Austin Codeworks, Austin, Texas (they are in the phone book). It's in decimal lat lon format, and has about 100k points total, including islands and lakes. Only a few inconsistancies. The data may also be available elsewhere, as it is shareware. If anyone knows of another such database, or of a topo map database, I'd love to hear about it. - Dan Kegel (dank@blacks.jpl.nasa.gov)
creator: dank
date: 1991-09-25T19:47:07-00:00