map.1 (13546B)
1 .TH MAP 1 2 .SH NAME 3 map, mapdemo, mapd \- draw maps on various projections 4 .SH SYNOPSIS 5 .B map 6 .I projection 7 [ 8 .I option ... 9 ] 10 .PP 11 .B mapdemo 12 .PP 13 .SH DESCRIPTION 14 .I Map 15 prepares on the standard output a 16 map suitable for display by any 17 plotting filter described in 18 .IR plot (1). 19 A menu of projections is produced in response to an unknown 20 .IR projection . 21 .I Mapdemo 22 is a short course in mapping. 23 .PP 24 The default data for 25 .I map 26 are world shorelines. 27 Option 28 .B -f 29 accesses more detailed data 30 classified by feature. 31 .TP 32 .BR -f " [ \fIfeature\fR ... ]" 33 Features are ranked 1 (default) to 4 from major to minor. 34 Higher-numbered ranks include all lower-numbered ones. 35 Features are 36 .RS 37 .TF country[1-3] 38 .TP 39 .BR shore [ 1 - 4 ] 40 seacoasts, lakes, and islands; option 41 .B -f 42 always shows 43 .B shore1 44 .TP 45 .BR ilake [ 1 - 2 ] 46 intermittent lakes 47 .TP 48 .BR river [ 1 - 4 ] 49 rivers 50 .TP 51 .BR iriver [ 1 - 3 ] 52 intermittent rivers 53 .TP 54 .BR canal [ 1 - 3 ] 55 .BR 3 =irrigation 56 canals 57 .TP 58 .BR glacier 59 .TP 60 .BR iceshelf [ 12 ] 61 .TP 62 .BR reef 63 .TP 64 .BR saltpan [ 12 ] 65 .TP 66 .BR country [ 1 - 3 ] 67 .BR 2 =disputed 68 boundaries, 69 .BR 3 =indefinite 70 boundaries 71 .TP 72 .BR state 73 states and provinces (US and Canada only) 74 .PD 75 .RE 76 .PP 77 In other options 78 coordinates are in degrees, with north latitude 79 and west longitude counted as positive. 80 .TP 0 81 .BI -l " S N E W" 82 Set the southern and northern latitude 83 and the eastern and western longitude limits. 84 Missing arguments are filled out from the list 85 \-90, 90, \-180, 180, 86 or lesser limits suitable to the 87 projection at hand. 88 .TP 89 .BI -k " S N E W 90 Set the scale as if for a map with limits 91 .B -l 92 .I "S N E W"\f1. 93 Do not consider any 94 .B -l 95 or 96 .B -w 97 option in setting scale. 98 .TP 99 .BI -o " lat lon rot" 100 Orient the map in a nonstandard position. 101 Imagine a transparent gridded sphere around the globe. 102 Turn the overlay about the North Pole 103 so that the Prime Meridian (longitude 0) 104 of the overlay coincides with meridian 105 .I lon 106 on the globe. 107 Then tilt the North Pole of the 108 overlay along its Prime Meridian to latitude 109 .I lat 110 on the globe. 111 Finally again turn the 112 overlay about its `North Pole' so 113 that its Prime Meridian coincides with the previous position 114 of meridian 115 .IR rot . 116 Project the map in 117 the standard form appropriate to the overlay, but presenting 118 information from the underlying globe. 119 Missing arguments are filled out from the list 120 90, 0, 0. 121 In the absence of 122 .BR - o , 123 the orientation is 90, 0, 124 .IR m , 125 where 126 .I m 127 is the middle of the longitude range. 128 .TP 129 .BI -w " S N E W" 130 Window the map by the specified latitudes 131 and longitudes in the tilted, rotated coordinate system. 132 Missing arguments are filled out from the list \-90, 90, \-180, 180. 133 (It is wise to give an encompassing 134 .B -l 135 option with 136 .BR -w . 137 Otherwise for small windows computing time 138 varies inversely with area!) 139 .TP 140 .BI -d " n" 141 For speed, plot only every 142 .IR n th 143 point. 144 .TP 145 .B -r 146 Reverse left and right 147 (good for star charts and inside-out views). 148 .ns 149 .TP 150 .B -v 151 Verso. 152 Switch to a normally suppressed sheet of the map, such as the 153 back side of the earth in orthographic projection. 154 .TP 155 .B -s1 156 .br 157 .ns 158 .TP 159 .B -s2 160 Superpose; outputs for a 161 .B -s1 162 map (no closing) and a 163 .B -s2 164 map (no opening) may be concatenated. 165 .TP 166 .BI -g " dlat dlon res" 167 Grid spacings are 168 .IR dlat , 169 .IR dlon . 170 Zero spacing means no grid. 171 Missing 172 .I dlat 173 is taken to be zero. 174 Missing 175 .I dlon 176 is taken the same as 177 .IR dlat . 178 Grid lines are drawn to a resolution of 179 .I res 180 (2° or less by default). 181 In the absence of 182 .BR - g , 183 grid spacing is 10°. 184 .TP 185 .BI -p " lat lon extent" 186 Position the point 187 .I lat, lon 188 at the center of the plotting area. 189 Scale the map so that the height (and width) of the 190 nominal plotting area is 191 .I extent 192 times the size of one degree of latitude 193 at the center. 194 By default maps are scaled and positioned 195 to fit within the plotting area. 196 An 197 .I extent 198 overrides option 199 .BR -k . 200 .TP 201 .BI -c " x y rot" 202 After all other positioning and scaling operations 203 have been performed, rotate the image 204 .I rot 205 degrees counterclockwise about the center 206 and move the center to position 207 .IR x , 208 .IR y , 209 where the nominal plotting area is 210 .RI \-1≤ x ≤1, 211 .RI \-1≤ y ≤1. 212 Missing arguments are taken to be 0. 213 .BR -x 214 Allow the map to extend outside the nominal plotting area. 215 .TP 216 .BR -m " [ \fIfile\fP ... ]" 217 Use 218 map data from named files. 219 If no files are named, omit map data. 220 Names that do not exist as pathnames are looked up in 221 a standard directory, which contains, in addition to the 222 data for 223 .BR -f , 224 .RS 225 .LP 226 .TF counties 227 .TP 228 .B world 229 World Data Bank I (default) 230 .TP 231 .B states 232 US map from Census Bureau 233 .TP 234 .B counties 235 US map from Census Bureau 236 .PD 237 .RE 238 .IP 239 The environment variables 240 .B MAP 241 and 242 .B MAPDIR 243 change the default 244 map and default directory. 245 .TP 246 .BI -b " \fR[\fPlat0 lon0 lat1 lon1\fR... ]" 247 Suppress the drawing of the normal boundary 248 (defined by options 249 .BR -l 250 and 251 .BR -w ). 252 Coordinates, if present, define the vertices of a 253 polygon to which the map is clipped. 254 If only two vertices are given, they are taken to be the 255 diagonal of a rectangle. 256 To draw the polygon, give its vertices as a 257 .B -u 258 track. 259 .TP 260 .BI -t " file ..." 261 The 262 .I files 263 contain lists of points, 264 given as latitude-longitude pairs in degrees. 265 If the first file is named 266 .LR - , 267 the standard input is taken instead. 268 The points of each list are plotted as connected `tracks'. 269 .IP 270 Points in a track file may be followed by label strings. 271 A label breaks the track. 272 A label may be prefixed by 273 \fL"\fR, 274 .LR : , 275 or 276 .L ! 277 and is terminated by a newline. 278 An unprefixed string or a string prefixed with 279 .L 280 " 281 is displayed at the designated point. 282 The first word of a 283 .L : 284 or 285 .L ! 286 string names a special symbol (see option 287 .BR -y ). 288 An optional numerical second word is a scale factor 289 for the size of the symbol, 1 by default. 290 A 291 .L : 292 symbol is aligned with its top to the north; a 293 .L ! 294 symbol is aligned vertically on the page. 295 .TP 296 .BI -u " file ..." 297 Same as 298 .BR -t , 299 except the tracks are 300 unbroken lines. 301 .RB ( -t 302 tracks appear as dot-dashed lines if the plotting filter supports them.) 303 .TP 304 .BI -y " file 305 The 306 .I file 307 contains 308 .MR plot (7) -style 309 data for 310 .L : 311 or 312 .L ! 313 labels in 314 .B -t 315 or 316 .B -u 317 files. 318 Each symbol is defined by a comment 319 .BI : name 320 then a sequence of 321 .L m 322 and 323 .L v 324 commands. 325 Coordinates (0,0) fall on the plotting point. 326 Default scaling is as if the nominal plotting range were 327 .LR "ra -1 -1 1 1" ; 328 .L ra 329 commands in 330 .I file 331 change the scaling. 332 .SS Projections 333 Equatorial projections centered on the Prime Meridian 334 (longitude 0). 335 Parallels are straight horizontal lines. 336 .PP 337 .PD 0 338 .TP 1.5i 339 .B mercator 340 equally spaced straight meridians, conformal, 341 straight compass courses 342 .TP 343 .B sinusoidal 344 equally spaced parallels, 345 equal-area, same as 346 .LR "bonne 0" . 347 .TP 348 .BI cylequalarea " lat0" 349 equally spaced straight meridians, equal-area, 350 true scale on 351 .I lat0 352 .TP 353 .B cylindrical 354 central projection on tangent cylinder 355 .TP 356 .BI rectangular " lat0" 357 equally spaced parallels, equally spaced straight meridians, true scale on 358 .I lat0 359 .TP 360 .BI gall " lat0" 361 parallels spaced stereographically on prime meridian, equally spaced straight 362 meridians, true scale on 363 .I lat0 364 .TP 365 .B mollweide 366 (homalographic) equal-area, hemisphere is a circle 367 .br 368 .B gilbert() 369 sphere conformally mapped on hemisphere and viewed orthographically 370 .TP 371 .B gilbert 372 globe mapped conformally on hemisphere, viewed orthographically 373 .PD 374 .PP 375 Azimuthal projections centered on the North Pole. 376 Parallels are concentric circles. 377 Meridians are equally spaced radial lines. 378 .PP 379 .PD 0 380 .TP 1.5i 381 .B azequidistant 382 equally spaced parallels, 383 true distances from pole 384 .TP 385 .B azequalarea 386 equal-area 387 .TP 388 .B gnomonic 389 central projection on tangent plane, 390 straight great circles 391 .TP 392 .BI perspective " dist" 393 viewed along earth's axis 394 .I dist 395 earth radii from center of earth 396 .TP 397 .B orthographic 398 viewed from infinity 399 .TP 400 .B stereographic 401 conformal, projected from opposite pole 402 .TP 403 .B laue 404 .IR radius " = tan(2\(mu" colatitude ), 405 used in X-ray crystallography 406 .TP 407 .BI fisheye " n" 408 stereographic seen from just inside medium with refractive index 409 .I n 410 .TP 411 .BI newyorker " r" 412 .IR radius " = log(" colatitude / r ): 413 .I New Yorker 414 map from viewing pedestal of radius 415 .I r 416 degrees 417 .PD 418 .PP 419 Polar conic projections symmetric about the Prime Meridian. 420 Parallels are segments of concentric circles. 421 Except in the Bonne projection, 422 meridians are equally spaced radial 423 lines orthogonal to the parallels. 424 .PP 425 .PD 0 426 .TP 1.5i 427 .BI conic " lat0" 428 central projection on cone tangent at 429 .I lat0 430 .TP 431 .BI simpleconic " lat0 lat1" 432 equally spaced parallels, true scale on 433 .I lat0 434 and 435 .I lat1 436 .TP 437 .BI lambert " lat0 lat1" 438 conformal, true scale on 439 .I lat0 440 and 441 .I lat1 442 .TP 443 .BI albers " lat0 lat1" 444 equal-area, true scale on 445 .I lat0 446 and 447 .I lat1 448 .TP 449 .BI bonne " lat0" 450 equally spaced parallels, equal-area, 451 parallel 452 .I lat0 453 developed from tangent cone 454 .PD 455 .PP 456 Projections with bilateral symmetry about 457 the Prime Meridian 458 and the equator. 459 .PP 460 .PD 0 461 .TP 1.5i 462 .B polyconic 463 parallels developed from tangent cones, 464 equally spaced along Prime Meridian 465 .TP 466 .B aitoff 467 equal-area projection of globe onto 2-to-1 468 ellipse, based on 469 .I azequalarea 470 .TP 471 .B lagrange 472 conformal, maps whole sphere into a circle 473 .TP 474 .BI bicentric " lon0" 475 points plotted at true azimuth from two 476 centers on the equator at longitudes 477 .IR ±lon0 , 478 great circles are straight lines 479 (a stretched 480 .IR gnomonic 481 ) 482 .TP 483 .BI elliptic " lon0" 484 points plotted at true distance from 485 two centers on the equator at longitudes 486 .I ±lon0 487 .TP 488 .B globular 489 hemisphere is circle, 490 circular arc meridians equally spaced on equator, 491 circular arc parallels equally spaced on 0- and 90-degree meridians 492 .TP 493 .B vandergrinten 494 sphere is circle, 495 meridians as in 496 .IR globular , 497 circular arc parallels resemble 498 .I mercator 499 .PD 500 .PP 501 Doubly periodic conformal projections. 502 .PP 503 .TP 1.5i 504 .B guyou 505 W and E hemispheres are square 506 .PD 0 507 .TP 508 .B square 509 world is square with Poles 510 at diagonally opposite corners 511 .TP 512 .B tetra 513 map on tetrahedron with edge 514 tangent to Prime Meridian at S Pole, 515 unfolded into equilateral triangle 516 .TP 517 .B hex 518 world is hexagon centered 519 on N Pole, N and S hemispheres are equilateral 520 triangles 521 .PD 522 .PP 523 Miscellaneous projections. 524 .PP 525 .PD 0 526 .TP 1.5i 527 .BI harrison " dist angle" 528 oblique perspective from above the North Pole, 529 .I dist 530 earth radii from center of earth, looking 531 along the Date Line 532 .I angle 533 degrees off vertical 534 .TP 535 .BI trapezoidal " lat0 lat1" 536 equally spaced parallels, 537 straight meridians equally spaced along parallels, 538 true scale at 539 .I lat0 540 and 541 .I lat1 542 on Prime Meridian 543 .PD 544 .br 545 .B lune(lat,angle) 546 conformal, polar cap above latitude 547 .I lat 548 maps to convex lune with given 549 .I angle 550 at 90\(deE and 90\(deW 551 .PP 552 Retroazimuthal projections. 553 At every point the angle between vertical and a straight line to 554 `Mecca', latitude 555 .I lat0 556 on the prime meridian, 557 is the true bearing of Mecca. 558 .PP 559 .PD 0 560 .TP 1.5i 561 .BI mecca " lat0" 562 equally spaced vertical meridians 563 .TP 564 .BI homing " lat0" 565 distances to Mecca are true 566 .PD 567 .PP 568 Maps based on the spheroid. 569 Of geodetic quality, these projections do not make sense 570 for tilted orientations. 571 For descriptions, see corresponding maps above. 572 .PP 573 .PD 0 574 .TP 1.5i 575 .B sp_mercator 576 .TP 577 .BI sp_albers " lat0 lat1" 578 .SH EXAMPLES 579 .TP 580 .L 581 map perspective 1.025 -o 40.75 74 582 A view looking down on New York from 100 miles 583 (0.025 of the 4000-mile earth radius) up. 584 The job can be done faster by limiting the map so as not to `plot' 585 the invisible part of the world: 586 .LR "map perspective 1.025 -o 40.75 74 -l 20 60 30 100". 587 A circular border can be forced by adding option 588 .LR "-w 77.33" . 589 (Latitude 77.33° falls just inside a polar cap of 590 opening angle arccos(1/1.025) = 12.6804°.) 591 .TP 592 .L 593 map mercator -o 49.25 -106 180 594 An `equatorial' map of the earth 595 centered on New York. 596 The pole of the map is placed 90\(de away (40.75+49.25=90) 597 on the 598 other side of the earth. 599 A 180° twist around the pole of the map arranges that the 600 `Prime Meridian' of the map runs from the pole of the 601 map over the North Pole to New York 602 instead of down the back side of the earth. 603 The same effect can be had from 604 .L 605 map mercator -o 130.75 74 606 .TP 607 .L 608 map albers 28 45 -l 20 50 60 130 -m states 609 A customary curved-latitude map of the United States. 610 .TP 611 .L 612 map harrison 2 30 -l -90 90 120 240 -o 90 0 0 613 A fan view covering 60° on either 614 side of the Date Line, as seen from one earth radius 615 above the North Pole gazing at the 616 earth's limb, which is 30° off vertical. 617 The 618 .B -o 619 option overrides the default 620 .BR "-o 90 0 180" , 621 which would rotate 622 the scene to behind the observer. 623 .SH FILES 624 .TF /lib/map/[1-4]?? 625 .TP 626 .B /lib/map/[1-4]?? 627 World Data Bank II, for 628 .B -f 629 .TP 630 .B /lib/map/* 631 maps for 632 .B -m 633 .TP 634 .B /lib/map/*.x 635 map indexes 636 .TP 637 .B mapd 638 Map driver program 639 .SH SOURCE 640 .B \*9/src/cmd/map 641 .SH "SEE ALSO" 642 .IR map (7), 643 .MR plot (1) 644 .SH DIAGNOSTICS 645 `Map seems to be empty'\(ema coarse survey found 646 zero extent within the 647 .B -l 648 and 649 .BR -w 650 bounds; for maps of limited extent 651 the grid resolution, 652 .IR res , 653 or the limits may have to be refined. 654 .SH BUGS 655 Windows (option 656 .BR -w ) 657 cannot cross the Date Line. 658 No borders appear along edges arising from 659 visibility limits. 660 Segments that cross a border are dropped, not clipped. 661 Excessively large scale or 662 .B -d 663 setting may cause long line segments to be dropped. 664 .I Map 665 tries to draw grid lines dotted and 666 .B -t 667 tracks dot-dashed. 668 As very few plotting filters properly support 669 curved textured lines, these lines are likely to 670 appear solid. 671 The west-longitude-positive convention 672 betrays Yankee chauvinism. 673 .I Gilbert 674 should be a map from sphere to sphere, independent of 675 the mapping from sphere to plane.