msb62@leah.Albany.Edu (Mitch Baltuch) (03/04/89)
I have to write an application which makes extensive use of maps. I need to be able to display the maps in polar stereographic, parabolic, and linear projections. Does any public domain software exist for doing this. I will be using a map database consisting of lat/lon pairs as vectors. Thanks, Mitch Baltuch Thunderstorm Analysis Center State University of New York ____________________________________________________________________________ Internet: msb62@leah.albany.edu Phone: (518) 442-4138 Bitnet: m.s.baltuch@albny1vx Snail Mail: State Univ. of NY at Albany ES235 ATM/SCI 1400 Washington Ave. Albany, New York 12222 Disclaimer: These opinions are only mine, but I love 'em anyway.
jxh@cup.portal.com (Jim - Hickstein) (03/06/89)
>...map projections...ortho...linear...neat stuff
I don't know, but if you find some, PLEASE let me know! I've been trying
to brain out all these wonderful projections I got in a book by the USGS,
but I'm afraid my formal education in trig is lacking. I, too, need to do
ortho, equatorial and oblique aspects, but nobody can tell me how to draw
a straight line (straight in the cartesian plane but not necessarily the
projected plane). Is there a more accessible book about this out there?ldm@texhrc.UUCP (Lyle Meier) (03/07/89)
In article <15458@cup.portal.com>, jxh@cup.portal.com (Jim - Hickstein) writes: > >...map projections...ortho...linear...neat stuff > > I don't know, but if you find some, PLEASE let me know! I've been trying There is a U.S.G.S. (U.S Geological Survey) bulletin 12xx or so about map projections, as well as a 40 year old coast and geodetic survey publication. There is also software available from U.S.G.S. in fortran for 19 common map projections. This software was available for the cost of a tape from usgs or ntis (National Techincal Information Service), at least it was 7 years ago.
paul@hpldola.HP.COM (Paul Bame) (03/08/89)
I was frustrated until I found the "Map Projections of the USGS" (or something like that - it's at home) book. I found it quite reasonable and just translated the projection I required (Albers EA) to C, ran the test cases in the book, and it worked fine. I didn't really puzzle out exactly *how* it worked. If you require the Albers projection, I'll send you the code (or even post it - it's small). -Paul Bame HP Colorado Springs 719 590 5557 paul@hpldola.hp.com hplabs!hpldola!paul
earl@vicorp.com (Earl Billingsley) (10/08/90)
I need source and or references for as many map projects as possible. For example, Hammer, Robinson, Dymaxion, Goode Homolosine, etc. I have ordered two publications (told they were useful) from the Committee on Map Projections of the American Cartographic Association: "Which Map is Best? Projections for World Maps" and "Choosing a World Map - Attributes, Distortions, Classes, Aspects". I don't know what these will contain in the way of algorithms but am interested in any help I can get. Thanks. Earl Billingsley V.I. Corp 47 Pleasant St. Northampton Ma. 01060 (413)586-4144 Tel. (413)586-3805 Fax
tcline@hpislx.HP.COM (Ted Cline) (10/10/90)
> / hpislx:comp.graphics / earl@vicorp.com (Earl Billingsley) / 8:00 am Oct 8, 1990 / > > I need source and or references for as many map projects as possible. > For example, Hammer, Robinson, Dymaxion, Goode Homolosine, etc. > I don't know what > these will contain in the way of algorithms but am interested in > any help I can get. Thanks. > > Earl Billingsley > V.I. Corp > 47 Pleasant St. > Northampton Ma. 01060 > (413)586-4144 Tel. > (413)586-3805 Fax > ---------- I have a copy of "Mapping the World in Pascal", (BYTE Magazine, Dec 1987, p329-334). It describes itself as "A cartographic sampler: Five Pascal mapping routines that give you the power to change the face of the earth". Which means given latitude and longitude line segment data, you can plot different map projections: Equidistant Cylindrical (rectangular, but Greenland short and wide) Sinusoidal (almost a diamond shape) Mercator (rectangular, but Greenland bigger than South America) Orthographic (Looks like photo of earth from space) Hammer (Oval) In the "FOR FURTHER READING" section: Johnston, William D., "Computer Generated Maps", BYTE, May and June 1979. McDonnell, Porter W. Jr., _Introduction_to_Map_Projections_, New York: Marcel Dekker, 1979. Snyder, John P., _Map_Projections_Used_by_the_U.S._Geological_ _Survey_, Geological Survey Bulletin 1532, 2nd ed. Washington, D.C.: U.S. Government Printing Office, 1982. ---- Ted Cline Measurement Systems Operation R&D Lab ted_cline@hpisla.lvld.hp.com Hewlett-Packard, CU-325 [ihnp4|hplabs]!hpislx!tcline 815 14th Street SW (303) 679-2352 Loveland, CO 80537 USA
6600phnx@ucsbuxa.ucsb.edu (Phoenix / Fig) (10/13/90)
If you want the defacto standards for map projections look up the U.S. Geological Survey. They have several publications on map projections, one called "Map Projections - A Working Manual (Paper 1395)" and there is another called something like 'The Atlas of Map Projections'. I have the first publication and it contains many formulas and specs. The second publication is basically what it says and contains many many projections. Check with the USGS (I'm sure you can find a telephone number or an order number, after all it is the government) or try a University library. My University has a government publications area that contains all the USGS publications, but I doubt that your typical public library would have the books. Anyway, I'v found all the information I need about the projections for the USGS, now as to display, this is of course a much more interesting problem . . . ..Mike Figueroa.......................... _______________________ . 6600phnx@ucsbuxa.ucsb.edu (Internet) . / // / . @ucsbuxa.bitnet (Bitnet) . /---- // / __ ......................................... / // / / "Vila weights 73 kilos . . ." / ------ ------
thomson@cs.utah.edu (Rich Thomson) (10/14/90)
> Snyder, John P., _Map_Projections_Used_by_the_U.S._Geological_ > _Survey_, Geological Survey Bulletin 1532, 2nd ed. Washington, D.C.: > U.S. Government Printing Office, 1982. Note: the professional paper I mentioned in my previous posting on the subject supercedes this document; Here's the preface from Professional Paper 1395: ``This publication is a major revision of USGS Bulletin 1532, which is titled _Map Projections Used by the US Geological Survey_. Although several portions are essentially unchanged except for corrections and clarification, there is considerable revision in the early general discussion, and the scope of the book, originally limited to map projections used by the U.S. Geological Survey, now extends to include several other popular or useful projections. These and dozens of other projections are described with less detail in the forthcoming USGS publication _An Album of Map Projections_. As before, this study of map projections is intended to be useful to both the reader interested in the philosophy or history of the projections and the reader desiring the mathematics. Under each of the projections described, the nonmathematical phases are presented first, without interruption by formulas. They are followed by the formulas and tables, which the first type of reader may skip entirely to pass to the nonmathematical section of the next projection. Even with the mathematics, there are almost no derivations and very little calculus. The emphasis is on describing the characteristics of the projection and how it is used. This professional paper, like Bulletin 1532, is also designed so that the user can turn directly to the desired projection, without reading any other section, in order to study the projection under consideration. However, the list of symbols may be needed in any case, and the random-access feature will be enhanced by a general understanding of the concepts of projections and distortion. As a result of this intent, there is some repetition which will be apparent when the book is read sequentially. For the more complicated projections, equations are given in the order of usage. Otherwise, major equations are given first, followed by subordinate equations. When an equation has been given previously, it is repeated with the original equation number, to avoid the need to leaf back and forth. Numerical examples, however, are placed in appendix A. It was felt that placing these with the formulas would only add to the difficulty of reading through the mathematical sections. The equations are frequently taken from other credited or standard sources, but a number of the equations have been derived or rearranged for this publication by the author. Further attention has been given to computer efficiency, for example by encouraging the use of nested power series in place of multiple-angle series. [acknowledgments deleted] John P. Snyder'' Rich Thomson thomson@cs.utah.edu {bellcore,hplabs,uunet}!utah-cs!thomson ``If everybody is thinking the same thing, is anybody thinking?'' --Bob Johnson
stead@beno.CSS.GOV (Richard Stead) (10/20/90)
In article <1990Oct8.140035.28512@vicorp.com>, earl@vicorp.com (Earl Billingsley) writes: > > I need source and or references for as many map projects as possible. I recommend _The World in Perspective_ (subtitle: a directory of world map projections) by F. Canters and H. Decleir, 181pp., John Wiley&Sons, 1989. It contains a complete mathematical theory of map projections, a classification, and all the formulae necessary to generate 50 generalized projections. If only they published the code used to generate the sample maps as well (sigh...) Richard Stead Center for Seismic Studies Arlington, VA stead@seismo.css.gov