From 78e51a8c6678b6e3dff3d619aa786669f531f4bc Mon Sep 17 00:00:00 2001 From: rsc Date: Fri, 14 Jan 2005 03:45:44 +0000 Subject: checkpoint --- man/man7/map.html | 108 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 108 insertions(+) create mode 100644 man/man7/map.html (limited to 'man/man7/map.html') diff --git a/man/man7/map.html b/man/man7/map.html new file mode 100644 index 00000000..1ebdfbba --- /dev/null +++ b/man/man7/map.html @@ -0,0 +1,108 @@ + +map(7) - Plan 9 from User Space + + + + +
+
+
MAP(7)MAP(7) +
+
+

NAME
+ +
+ + map – digitized map formats
+ +
+

DESCRIPTION
+ +
+ + Files used by map(7) are a sequence of structures of the form: + +
+ + struct {
+ +
+ + signed char patchlatitude;
+ signed char patchlongitude;
+ short n;
+ union {
+ +
+ + struct {
+ short latitude;
+ short longitude;
+ } point[n];
+ struct {
+ short latitude;
+ short longitude;
+ struct {
+ signed char latdiff;
+ signed char londiff;
+ } point[–n];
+ } highres;
+ +
+ } segment;
+ +
+ };
+ where short stands for 16-bit integers and there is no padding + within or between structs. Shorts are stored in little-endian + order, low byte first. To assure portability, map accesses them + bytewise. +
+ + Fields patchlatitude and patchlongitude tell to what 10-degree + by 10-degree patch of the earth’s surface a segment belongs. Their + values range from –9 to 8 and from –18 to 17, respectively, and + indicate the coordinates of the southeast corner of the patch + in units of 10 degrees. +
+ + Each segment of |n| points is connected; consecutive segments + are not necessarily related. Latitude and longitude are measured + in units of 0.0001 radian. If n is negative, then differences + to the first and succeeding points are measured in units of 0.00001 + radian. Latitude is counted positive to the north and longitude + positive to the west. +
+ + The patches are ordered lexicographically by patchlatitude then + patchlongitude. A printable index to the first segment of each + patch in a file named data is kept in an associated file named + data.x. Each line of an index file contains patchlatitude, patchlongitude + and the byte position of the + patch in the map file. Both the map file and the index file are + ordered by patch latitude and longitude.
+ +
+

SEE ALSO
+ +
+ + map(7)
+ The data comes from the World Data Bank I and II and U.S. Government + sources: the Census Bureau, Geological Survey, and CIA.
+ +
+ +

 +
+
+ + +
+
+
+Space Glenda +
+
+ + -- cgit v1.2.3