| 12 |
<author> |
<author> |
| 13 |
<firstname>Jan-Oliver</firstname><surname>Wagner</surname> |
<firstname>Jan-Oliver</firstname><surname>Wagner</surname> |
| 14 |
</author> |
</author> |
| 15 |
|
<author> |
| 16 |
|
<firstname>Frank</firstname><surname>Koormann</surname> |
| 17 |
|
</author> |
| 18 |
<copyright> |
<copyright> |
| 19 |
<year>2003</year> |
<year>2003</year> |
| 20 |
<holder>Intevation GmbH</holder> |
<holder>Intevation GmbH</holder> |
| 59 |
<screenshot> |
<screenshot> |
| 60 |
<screeninfo>The Main Window</screeninfo> |
<screeninfo>The Main Window</screeninfo> |
| 61 |
<mediaobject> |
<mediaobject> |
| 62 |
<imageobject><imagedata fileref="../mainwindow.png" format="PNG"/></imageobject> |
<imageobject> <imagedata fileref="../images/1_2_mainwindow.png" format="PNG"/> </imageobject> |
| 63 |
|
<imageobject> <imagedata fileref="./images/1_2_mainwindow.ps" format="EPS"/> </imageobject> |
| 64 |
<textobject><phrase>The Main Window</phrase></textobject> |
<textobject><phrase>The Main Window</phrase></textobject> |
| 65 |
<caption><para>The Main Window</para></caption> |
<caption><para>The Main Window</para></caption> |
| 66 |
</mediaobject> |
</mediaobject> |
| 68 |
</para> |
</para> |
| 69 |
|
|
| 70 |
<para> |
<para> |
| 71 |
The map window (1) shows the current state of the map and is where |
The map window shows the current state of the map and is where |
| 72 |
the user can interact with the map using the tools. |
the user can interact with the map using the tools. |
| 73 |
</para> |
</para> |
| 74 |
|
|
| 75 |
<para> |
<para> |
| 76 |
The legend on |
The legend on the left displays a list of the current layers and |
| 77 |
the left (2) displays a list of the current layers and any visible |
any visible classification groups. In the example, each shape layer |
| 78 |
classification groups. In the example, each shape layer has a default |
has a default classification which specifies how the shapes in each |
| 79 |
classification which specifies how the shapes in each layer are |
layer are drawn. Layers that are higher in the list appear |
| 80 |
drawn. Layers that are higher in the list appear ``closer'' to the |
``closer'' to the user. The legend can be closed by clicking on the |
| 81 |
user. The legend can be closed by clicking on the small X in the |
small X in the upper right-hand region of the legend. |
| 82 |
upper right-hand region of the legend. To open it again, use |
To open it again, use |
| 83 |
<menuchoice> |
<menuchoice> |
| 84 |
<guimenu>Map</guimenu> |
<guimenu>Map</guimenu> |
| 85 |
<guimenuitem>Legend</guimenuitem> |
<guimenuitem>Legend</guimenuitem> |
| 86 |
</menuchoice>. |
</menuchoice>. |
| 87 |
The legend is also dockable, which means that it can be detached |
The legend is also dockable, which means that it can be detached |
| 88 |
from the main window by clicking on the small button next to the |
from the main window by clicking on the small button next to the |
| 89 |
close button. It can be attached again by clicking the same button |
close button. It can be attached by clicking the same button |
| 90 |
again. |
again. |
| 91 |
</para> |
</para> |
| 92 |
<para> |
<para> |
| 93 |
The status bar (3) displays different information depending on the |
The status bar displays different information depending on the |
| 94 |
current context. If the user is selecting an item from the menu |
current context. If the user is selecting an item from the menu |
| 95 |
then the status bar will display a short help message indicating |
then the status bar will display a short help message indicating |
| 96 |
what each menu item is for. If the user has a tool selected then |
what each menu item is for. If the user has a tool selected then |
| 97 |
the position of the cursor on the map is displayed. |
the position of the cursor on the map is displayed. |
| 98 |
</para> |
</para> |
| 99 |
<para> |
<para> |
| 100 |
The tool bar (4) provides quick access to the commonly needed tools. |
The tool bar provides quick access to the commonly needed tools. |
| 101 |
By hovering over each button the user can see a short messages |
By hovering over each button the user can see a short messages |
| 102 |
describing what the tool does. The tools provided are Zoom In, Zoom |
describing what the tool does. The tools provided are Zoom In, Zoom |
| 103 |
Out, Pan, Full Extent, Full Layer Extent, Full Shape Extent, Indentify, |
Out, Pan, Full Extent, Full Layer Extent, Full Shape Extent, Indentify, |
| 159 |
|
|
| 160 |
<chapter><title>Map Management</title> |
<chapter><title>Map Management</title> |
| 161 |
<para> |
<para> |
| 162 |
|
The map consists of a number of layers where each layer represents a |
| 163 |
|
different type of data set. By interacting with the map the user can |
| 164 |
|
visually explore the data. |
| 165 |
</para> |
</para> |
| 166 |
|
|
| 167 |
<section><title>Adding and Removing Layers</title> |
<section><title>Adding and Removing Layers</title> |
| 168 |
<para> |
<para> |
| 169 |
|
There are two types of layers that can use added to a map: shape layers |
| 170 |
|
and image layers. Shape layers are stored in Shapefile format, a |
| 171 |
|
standard file format for storing geographic objects. Normally, these |
| 172 |
|
files have the extension ``.shp''. Associated with |
| 173 |
|
the object information is a database file which stores attributes for |
| 174 |
|
each shape in the Shapefile. This file, stored in DB2 format, usually |
| 175 |
|
has the extension ``.dbf''. Both files should have the same base name. |
| 176 |
|
For example, if there is a Shapefile named roads.shp there should |
| 177 |
|
also be a file roads.dbf. |
| 178 |
|
</para> |
| 179 |
|
<para> |
| 180 |
|
Shape layers can be added to the map with |
| 181 |
|
<menuchoice> |
| 182 |
|
<guimenu>Map</guimenu> |
| 183 |
|
<guimenuitem>Add Layer</guimenuitem> |
| 184 |
|
</menuchoice>. |
| 185 |
|
Thuban will load all files with the same base name, so it doesn't |
| 186 |
|
matter if the Shapefile or database file is selected. |
| 187 |
|
</para> |
| 188 |
|
|
| 189 |
|
<para> |
| 190 |
|
Image layers can be added to the map with |
| 191 |
|
<menuchoice> |
| 192 |
|
<guimenu>Map</guimenu> |
| 193 |
|
<guimenuitem>Add Image Layer</guimenuitem> |
| 194 |
|
</menuchoice>. |
| 195 |
|
It is important to select a valid image file that has geographic |
| 196 |
|
data associated with it. This can be embedded in the file itself, |
| 197 |
|
or in another file. If geographic information cannot be found, Thuban |
| 198 |
|
will report an error. |
| 199 |
</para> |
</para> |
| 200 |
</section> |
</section> |
| 201 |
|
|
| 202 |
<section><title>Navigation</title> |
<section><title>Navigation</title> |
| 203 |
<para> |
<para> |
| 204 |
|
The map can be explored by using the navigation tools available on |
| 205 |
|
the tool bar, or from the |
| 206 |
|
<menuchoice><guimenu>Map</guimenu></menuchoice> menu. |
| 207 |
|
</para> |
| 208 |
|
<para> |
| 209 |
|
The ZoomIn tool |
| 210 |
|
<inlinemediaobject> |
| 211 |
|
<imageobject> |
| 212 |
|
<imagedata fileref="../images/3_2_zoomin.png" format="PNG"/> |
| 213 |
|
</imageobject> |
| 214 |
|
<imageobject> |
| 215 |
|
<imagedata fileref="./images/3_2_zoomin.eps" format="EPS"/> |
| 216 |
|
</imageobject> |
| 217 |
|
<textobject> <phrase>ZoomIn Tool</phrase> </textobject> |
| 218 |
|
</inlinemediaobject> |
| 219 |
|
can be used to enlarge a region of the map. Clicking once on the map |
| 220 |
|
will double the magnification and center the map on the point that |
| 221 |
|
was clicked. Clicking and dragging lets the user select a region |
| 222 |
|
to be enlarged to fit the window. |
| 223 |
|
</para> |
| 224 |
|
<para> |
| 225 |
|
The ZoomOut tool |
| 226 |
|
<inlinemediaobject> |
| 227 |
|
<imageobject> |
| 228 |
|
<imagedata fileref="../images/3_2_zoomout.png" format="PNG"/> |
| 229 |
|
</imageobject> |
| 230 |
|
<imageobject> |
| 231 |
|
<imagedata fileref="./images/3_2_zoomout.eps" format="EPS"/> |
| 232 |
|
</imageobject> |
| 233 |
|
<textobject> <phrase>ZoomOut Tool</phrase> </textobject> |
| 234 |
|
</inlinemediaobject> |
| 235 |
|
shrinks the map so that a larger region is visible. A single click |
| 236 |
|
reduces the magnification by a factor of two. Clicking and dragging |
| 237 |
|
selects a box such that the current contents of the window will be |
| 238 |
|
scaled to fit into that box. |
| 239 |
|
</para> |
| 240 |
|
<para> |
| 241 |
|
The Pan tool |
| 242 |
|
<inlinemediaobject> |
| 243 |
|
<imageobject> |
| 244 |
|
<imagedata fileref="../images/3_2_pan.png" format="PNG"/> |
| 245 |
|
</imageobject> |
| 246 |
|
<imageobject> |
| 247 |
|
<imagedata fileref="./images/3_2_pan.eps" format="EPS"/> |
| 248 |
|
</imageobject> |
| 249 |
|
<textobject> <phrase>Pan Tool</phrase> </textobject> |
| 250 |
|
</inlinemediaobject> |
| 251 |
|
allows the user to move the map around by clicking and dragging. |
| 252 |
|
</para> |
| 253 |
|
<para> |
| 254 |
|
The Full Extent tool |
| 255 |
|
<inlinemediaobject> |
| 256 |
|
<imageobject> |
| 257 |
|
<imagedata fileref="../images/3_2_fullextent.png" format="PNG"/> |
| 258 |
|
</imageobject> |
| 259 |
|
<imageobject> |
| 260 |
|
<imagedata fileref="./images/3_2_fullextent.eps" format="EPS"/> |
| 261 |
|
</imageobject> |
| 262 |
|
<textobject> <phrase>Full Extent Tool</phrase> </textobject> |
| 263 |
|
</inlinemediaobject> |
| 264 |
|
rescales the viewable region so that the entire map is visible. |
| 265 |
|
</para> |
| 266 |
|
<para> |
| 267 |
|
The Full Layer Extent tool |
| 268 |
|
<inlinemediaobject> |
| 269 |
|
<imageobject> |
| 270 |
|
<imagedata fileref="../images/3_2_fulllayerextent.png" format="PNG"/> |
| 271 |
|
</imageobject> |
| 272 |
|
<imageobject> |
| 273 |
|
<imagedata fileref="./images/3_2_fulllayerextent.eps" format="EPS"/> |
| 274 |
|
</imageobject> |
| 275 |
|
<textobject> <phrase>Full Layer Extent Tool</phrase> </textobject> |
| 276 |
|
</inlinemediaobject> |
| 277 |
|
rescales the viewable region so that the currently selected |
| 278 |
|
layer fits within the window. If no layer is selected this button |
| 279 |
|
will be disabled. |
| 280 |
|
</para> |
| 281 |
|
<para> |
| 282 |
|
The Full Shape Extent tool |
| 283 |
|
<inlinemediaobject> |
| 284 |
|
<imageobject> |
| 285 |
|
<imagedata fileref="../images/3_2_fullshapeextent.png" format="PNG"/> |
| 286 |
|
</imageobject> |
| 287 |
|
<imageobject> |
| 288 |
|
<imagedata fileref="./images/3_2_fullshapeextent.eps" format="EPS"/> |
| 289 |
|
</imageobject> |
| 290 |
|
<textobject> <phrase>Full Shape Extent Tool</phrase> </textobject> |
| 291 |
|
</inlinemediaobject> |
| 292 |
|
rescales the viewable region so that the currently selected |
| 293 |
|
shape fits within the window. If the shape is a point, it is |
| 294 |
|
centered and the map is zoomed all the way in. If no shape is |
| 295 |
|
selected this button will be disabled. |
| 296 |
</para> |
</para> |
| 297 |
</section> |
</section> |
| 298 |
|
|
| 299 |
<section><title>Object Identification</title> |
<section><title>Object Identification</title> |
| 300 |
<para> |
<para> |
| 301 |
|
Objects on the map can be identified using the Identify tool |
| 302 |
|
<inlinemediaobject> |
| 303 |
|
<imageobject> |
| 304 |
|
<imagedata fileref="../images/3_3_identify.png" format="PNG"/> |
| 305 |
|
</imageobject> |
| 306 |
|
<imageobject> |
| 307 |
|
<imagedata fileref="./images/3_3_identify.eps" format="EPS"/> |
| 308 |
|
</imageobject> |
| 309 |
|
<textobject> <phrase>Identify Tool</phrase> </textobject> |
| 310 |
|
</inlinemediaobject>. |
| 311 |
|
Clicking on an object selects that object and opens a dialog which |
| 312 |
|
shows all the table attributes for that object. Any current selection |
| 313 |
|
is lost. |
| 314 |
</para> |
</para> |
| 315 |
</section> |
</section> |
| 316 |
|
|
| 317 |
<section><title>Object Labelling</title> |
<section><title>Object Labelling</title> |
| 318 |
<para> |
<para> |
| 319 |
|
Objects can be labelled using the Label tool |
| 320 |
|
<inlinemediaobject> |
| 321 |
|
<imageobject> |
| 322 |
|
<imagedata fileref="../images/3_3_label.png" format="PNG"/> |
| 323 |
|
</imageobject> |
| 324 |
|
<imageobject> |
| 325 |
|
<imagedata fileref="./images/3_3_label.eps" format="EPS"/> |
| 326 |
|
</imageobject> |
| 327 |
|
<textobject> <phrase>Label Tool</phrase> </textobject> |
| 328 |
|
</inlinemediaobject>. |
| 329 |
|
Clicking on an object selects that object and opens a dialog which |
| 330 |
|
displays the table attributes for that object. An attribute can |
| 331 |
|
be selected to be the label on the map. Using this tool for an |
| 332 |
|
object that already has a label will remove the label. |
| 333 |
</para> |
</para> |
| 334 |
</section> |
</section> |
| 335 |
|
|
| 336 |
<section><title>The Legend</title> |
<section><title>The Legend</title> |
| 337 |
<para> |
<para> |
| 338 |
|
The Legend provides an overview of the layers in the map. Layers |
| 339 |
|
that appear higher in the legend will appear ``closer'' to the user. |
| 340 |
|
If a layer supports classification (currently, only shape layers |
| 341 |
|
have this feature) then the classification groups will be shown |
| 342 |
|
below each layer. The properties for each group are also displayed |
| 343 |
|
with a small graphic. Polygon layers appear as rectangles, lines |
| 344 |
|
appear as curved lines, and points appear as circles. |
| 345 |
|
</para> |
| 346 |
|
<para> |
| 347 |
|
Along the top of the legend is a toolbar which allows quick access |
| 348 |
|
to some of the layer manipulation options under |
| 349 |
|
<menuchoice> <guimenu>Map</guimenu> </menuchoice>. |
| 350 |
|
|
| 351 |
|
Double-clicking on a layer or a group of a layer will open the |
| 352 |
|
properties dialog for that layer. |
| 353 |
</para> |
</para> |
| 354 |
</section> |
</section> |
| 355 |
|
|
| 356 |
<section><title>Printing</title> |
<section><title>Printing</title> |
| 357 |
<para> |
<para> |
| 358 |
|
The map can be printed using |
| 359 |
|
<menuchoice> |
| 360 |
|
<guimenu>Map</guimenu> |
| 361 |
|
<guimenuitem>Print</guimenuitem> |
| 362 |
|
</menuchoice>. A standard printing dialog will open allowing the |
| 363 |
|
user to configure the printer. |
| 364 |
</para> |
</para> |
| 365 |
</section> |
</section> |
| 366 |
</chapter> |
</chapter> |
| 371 |
|
|
| 372 |
<section><title>Types of Layers</title> |
<section><title>Types of Layers</title> |
| 373 |
<para> |
<para> |
| 374 |
|
There are two types of layers supported by Thuban: shape layers and |
| 375 |
|
image layers. Shape layers consist of vector based shapes with |
| 376 |
|
geo-referenced coordinates. There are three types of supported |
| 377 |
|
shapes: polygons, lines, and points. Image layers can be any image |
| 378 |
|
file format supported by GDAL. The images must have geographic |
| 379 |
|
coordinate data either embedded within the file, or in a seperate |
| 380 |
|
file that is in the same directory as the image file. GeoTIFF files |
| 381 |
|
work very well with Thuban and were designed specifically to be image |
| 382 |
|
layers in GIS programs. |
| 383 |
</para> |
</para> |
| 384 |
</section> |
</section> |
| 385 |
|
|
| 386 |
<section><title>Visibility</title> |
<section><title>Properties</title> |
| 387 |
<para> |
<para> |
| 388 |
|
Each shape in a shape layer can have various properties which control |
| 389 |
|
how it is drawn on the map. Polygons and points can be drawn with an |
| 390 |
|
outline color and a fill color, while lines have only a line color. |
| 391 |
</para> |
</para> |
| 392 |
</section> |
</section> |
| 393 |
|
|
| 394 |
<section><title>Sequence</title> |
<section><title>Visibility</title> |
| 395 |
<para> |
<para> |
| 396 |
|
Sometimes it is not desirable to view all layers at the same time. |
| 397 |
|
Some layers may take a long time to draw and so while navigating |
| 398 |
|
around the map the user may not want to wait for the map to redraw |
| 399 |
|
each time the map is changed. Each layer can be independently |
| 400 |
|
turned on or off using the |
| 401 |
|
<menuchoice> |
| 402 |
|
<guimenu>Layer</guimenu> |
| 403 |
|
<guimenuitem>Show</guimenuitem> |
| 404 |
|
</menuchoice> |
| 405 |
|
or |
| 406 |
|
<menuchoice> |
| 407 |
|
<guimenu>Layer</guimenu> |
| 408 |
|
<guimenuitem>Hide</guimenuitem> |
| 409 |
|
</menuchoice> options respectively. |
| 410 |
</para> |
</para> |
| 411 |
</section> |
</section> |
| 412 |
|
|
| 413 |
<section><title>Duplication</title> |
<section><title>Sequence</title> |
| 414 |
<para> |
<para> |
| 415 |
</para> |
</para> |
| 416 |
</section> |
</section> |
| 417 |
|
|
| 418 |
<section><title>Properties</title> |
<section><title>Duplication</title> |
| 419 |
<para> |
<para> |
| 420 |
|
Layers and all their properties, including classifications, can |
| 421 |
|
be duplicated using |
| 422 |
|
<menuchoice> |
| 423 |
|
<guimenu>Layer</guimenu> |
| 424 |
|
<guimenuitem>Duplicate</guimenuitem> |
| 425 |
|
</menuchoice>. Duplicating a layer is useful if the user wishes |
| 426 |
|
to model a layer in several different ways. Even though the layers |
| 427 |
|
overlap by carefully selecting the shape properties it is possible |
| 428 |
|
to display several pieces of information at once. For example, one |
| 429 |
|
copy of a roads layer may be classified on a length property and |
| 430 |
|
another copy may be classified on a type property. if the length |
| 431 |
|
property was expressed with color and the type property expressed |
| 432 |
|
with line thickness then it would be possible to view both |
| 433 |
|
classifications by placing the type property copy over the |
| 434 |
|
length property copy. |
| 435 |
</para> |
</para> |
| 436 |
</section> |
</section> |
| 437 |
|
|
| 438 |
</chapter> |
</chapter> |
| 439 |
|
|
| 440 |
<chapter><title>Layer Classifications</title> |
<chapter><title>Layer Classifications</title> |
| 441 |
<para> |
<para> |
| 442 |
</para> |
A layer classification is a way of assigning drawing properties to |
| 443 |
|
groups of shapes based on attributes stored in the layer's table. |
| 444 |
<section><title>Adding and Removing Classes</title> |
Only layer's with shapes can have a classification; image layers |
| 445 |
<para> |
cannot be classified. |
| 446 |
|
</para> |
| 447 |
|
<para> |
| 448 |
|
A classification consists of a number of groups, with each group |
| 449 |
|
having a value or range of values to match against, and symbol |
| 450 |
|
properties which control how a shape is drawn on the map. The user |
| 451 |
|
selects which field in the table is used by the classification and |
| 452 |
|
when the map is drawn the value for that field for each shape is |
| 453 |
|
compared with each group's value. The properties of the first group |
| 454 |
|
to match are used to draw the shape. This allows the user to get a |
| 455 |
|
visual impression of not only how the data is laid out but also what |
| 456 |
|
kind of data lies where. |
| 457 |
|
</para> |
| 458 |
|
<para> |
| 459 |
|
A layer always has a classification. When a new layer is added to the |
| 460 |
|
map, a default classification is created with the DEFAULT group. This |
| 461 |
|
group cannot be removed. Every shape in the layer, regardless of its |
| 462 |
|
attributes, will match this group. |
| 463 |
|
</para> |
| 464 |
|
|
| 465 |
|
<section><title>Editing Classifications</title> |
| 466 |
|
<para> |
| 467 |
|
A layer's classification can be modified under the properties dialog |
| 468 |
|
(<menuchoice> |
| 469 |
|
<guimenu>Layer</guimenu> |
| 470 |
|
<guimenuitem>Properties</guimenuitem> |
| 471 |
|
</menuchoice>). The layer's classification field can be set to None, |
| 472 |
|
which simply assigns a DEFAULT group to the classification. No new |
| 473 |
|
groups can be added to the classification if the field is None. |
| 474 |
|
The user must first select a field to classify on. New groups can |
| 475 |
|
be added to the classification with the <guibutton>Add</guibutton> |
| 476 |
|
button. |
| 477 |
|
</para> |
| 478 |
|
<para> |
| 479 |
|
The order of the groups in the classification is significant |
| 480 |
|
except for the DEFAULT group, which remains at the top. When shapes |
| 481 |
|
are matched against groups the matching begins at the first group |
| 482 |
|
other than the DEFAULT group so that groups higher in the list will |
| 483 |
|
be checked first. Matching for a |
| 484 |
|
given shape will stop at the first group that matches. The user can |
| 485 |
|
use <guibutton>Move Up</guibutton> and <guibutton>Move Down</guibutton> |
| 486 |
|
to change the order of the groups. The DEFAULT group will always |
| 487 |
|
match a shape that hasn't matched another group. |
| 488 |
</para> |
</para> |
| 489 |
|
<para> |
| 490 |
|
The Value column of the classification table is the value that will |
| 491 |
|
be matched when the map is being drawn. The type of data that can |
| 492 |
|
entered into this field depends on the type of data of the |
| 493 |
|
classification field. |
| 494 |
|
</para> |
| 495 |
|
<para> |
| 496 |
|
If the field is of type Text, anything entered |
| 497 |
|
into the field is valid. The text will be compared literally to the |
| 498 |
|
value of the shape attribute, including case sensitivity. |
| 499 |
|
If the type is Integer, then any valid integer may be entered. In |
| 500 |
|
addition, with special syntax, a range of values can be entered. |
| 501 |
|
A range from <varname>start</varname> to <varname>end</varname> |
| 502 |
|
inclusive is specifed like this: <literal>[start;end]</literal>. |
| 503 |
|
The exclusive range is specified like this: |
| 504 |
|
<literal>]start;end[</literal>. Ranges can include infinity like |
| 505 |
|
this: <literal>[-oo;oo]</literal>. Field types can also be of type |
| 506 |
|
Decimal. They represent any rational number and can be used in ranges |
| 507 |
|
as well. |
| 508 |
|
</para> |
| 509 |
</section> |
</section> |
| 510 |
|
|
| 511 |
<section><title>Symbols</title> |
<section><title>Symbols</title> |
| 512 |
<para> |
<para> |
| 513 |
|
Each type of shape has its own type of symbol. Thuban supports three |
| 514 |
|
types of shapes: polygons, lines, and points. Polygons and points have |
| 515 |
|
outline and fill color, while lines have only line color. Each group |
| 516 |
|
has associated symbol properties. To edit the symbol properties for a |
| 517 |
|
group the user can double click on the Symbol column or select a |
| 518 |
|
group and click the <guibutton>Edit Symbol</guibutton> button. |
| 519 |
</para> |
</para> |
| 520 |
</section> |
</section> |
| 521 |
|
|
| 522 |
<section><title>Generating Classes</title> |
<section><title>Generating Classes</title> |
| 523 |
<para> |
<para> |
| 524 |
|
Creating a classification by hand can be tedious. |
| 525 |
|
Thuban, therefore, provides a means of generating an entire |
| 526 |
|
classification at once while still giving the user control over |
| 527 |
|
how it appears. Clicking <guibutton>Generate Class</guibutton> |
| 528 |
|
opens the <varname>Generate Classification</varname> dialog. |
| 529 |
|
Under the <varname>Generate</varname> pulldown there are at most |
| 530 |
|
three different ways to generate classifications: |
| 531 |
|
Unique Values, Unique Distribution, and Quantiles. Some options |
| 532 |
|
may not be available if they data type for the field does not |
| 533 |
|
support them. For instance, <varname>Unique Distribution</varname> |
| 534 |
|
doesn't make sense for a Text field. |
| 535 |
</para> |
</para> |
| 536 |
|
<para> |
| 537 |
|
For every way of generating a classification, a color scheme must |
| 538 |
|
be selected. Thuban provides several different color schemes that |
| 539 |
|
affect how the group properties change over the classification. |
| 540 |
|
It is also possible to create a custom color scheme. Selecting |
| 541 |
|
this option will display two symbols: the one of the left has the |
| 542 |
|
properties of the first group and the one on the right has the |
| 543 |
|
properties of the last group. Thuban will interpolate between these |
| 544 |
|
two properties to generate the other groups. |
| 545 |
|
</para> |
| 546 |
|
<para> |
| 547 |
|
The Unique Values option lets the user select specific values that |
| 548 |
|
appear in the table. Clicking <guibutton>Retrieve From Table</guibutton> |
| 549 |
|
searches the table for all unique values and displays them in the |
| 550 |
|
list on the left. Items can be selected and moved to the list on the |
| 551 |
|
right. Each list can be sorted or reversed for easier searching. |
| 552 |
|
The classification that is generated will be in the same order as |
| 553 |
|
the list on the right. |
| 554 |
|
</para> |
| 555 |
|
<para> |
| 556 |
|
The Unique Distribution option creates a user specified number of |
| 557 |
|
groups of ranges such that each range covers equal intervals. The |
| 558 |
|
minimum and maximum values can automatically be retrieved from the |
| 559 |
|
table by clicking <guibutton>Retrieve From Table</guibutton>. The |
| 560 |
|
stepping is how large each interval is. Adjusting this value will |
| 561 |
|
automatically recalculate how many groups is appropriate. |
| 562 |
|
</para> |
| 563 |
|
<para> |
| 564 |
|
The Quantiles option generates ranges based on the number items |
| 565 |
|
in the input set. For example, by specifying 5 groups Thuban will |
| 566 |
|
generate groups with appropriate ranges such that 20% of the table |
| 567 |
|
data is in each group. If it is impossible to generate exact |
| 568 |
|
grouping, Thuban will issue a warning but allow the user to continue. |
| 569 |
|
</para> |
| 570 |
</section> |
</section> |
| 571 |
</chapter> |
</chapter> |
| 572 |
|
|
| 573 |
<chapter><title>Projection Management</title> |
<chapter><title>Projection Management</title> |
| 574 |
<para> |
<para> |
| 575 |
|
Projections control how the geographic data is displayed on the screen. |
| 576 |
|
If multiple layers are loaded into Thuban where the geographic data |
| 577 |
|
is in a different projection system, then the user must tell Thuban |
| 578 |
|
which projection each layer has. The user must also tell Thuban which |
| 579 |
|
projection the map is in. This can be the same as the layers or a different |
| 580 |
|
projection in which case the layers are reprojected into that space. |
| 581 |
|
The map projection can be set using |
| 582 |
|
<menuchoice> |
| 583 |
|
<guimenu>Map</guimenu> |
| 584 |
|
<guimenuitem>Projection</guimenuitem> |
| 585 |
|
</menuchoice> and the layer projection can be set using |
| 586 |
|
<menuchoice> |
| 587 |
|
<guimenu>Layer</guimenu> |
| 588 |
|
<guimenuitem>Projection</guimenuitem> |
| 589 |
|
</menuchoice>. |
| 590 |
|
</para> |
| 591 |
|
<para> |
| 592 |
|
Thuban is distributed with a sample collection of projections. The |
| 593 |
|
user can create new projections and make them available to all |
| 594 |
|
future Thuban sessions. They may also be exported and imported so |
| 595 |
|
that custom projections can be distributed to others. |
| 596 |
</para> |
</para> |
| 597 |
|
<section><title>Selecting a Projection</title> |
| 598 |
|
<para> |
| 599 |
|
The available projections are listed on the left. If the layer |
| 600 |
|
or map already has a projection it will be initially highlighted |
| 601 |
|
and will end with <varname>(current)</varname>. Selecting |
| 602 |
|
<varname>None</varname> will cause Thuban to use the data as |
| 603 |
|
it appears in the source file and will not use a projection. |
| 604 |
|
</para> |
| 605 |
|
</section> |
| 606 |
|
<section><title>Editing a Projection</title> |
| 607 |
|
<para> |
| 608 |
|
Whenever a projection is selected from the list its properties |
| 609 |
|
are displayed on the right. These properties can be changed |
| 610 |
|
and the changes saved to the selected projection using |
| 611 |
|
the <guibutton>Update</guibutton>. Only a projection that comes |
| 612 |
|
from a file can be updated, so if the current layer's projection |
| 613 |
|
is selectd, <guibutton>Update</guibutton> will be disabled. |
| 614 |
|
The <guibutton>Add to List</guibutton> adds the projection to the |
| 615 |
|
list of available projections as a new entry, and thus make it |
| 616 |
|
available to future Thuban sessions. Clicking <guibutton>New</guibutton> |
| 617 |
|
will create an entirely new, empty projection. The |
| 618 |
|
<guibutton>Remove</guibutton> button will permanantly remove a |
| 619 |
|
projection from the list of available projections. |
| 620 |
|
</para> |
| 621 |
|
</section> |
| 622 |
|
<section><title>Importing/Exporting Projections</title> |
| 623 |
|
<para> |
| 624 |
|
The projections that appear in the list of available projections |
| 625 |
|
can be exported to another file that the user chooses. By selecting |
| 626 |
|
one or more projections and clicking <guibutton>Export</guibutton> |
| 627 |
|
the user will be able to select a file to store those projections. |
| 628 |
|
The file can then be distributed to other Thuban users. To import |
| 629 |
|
a projection file the user can click <guibutton>Import</guibutton>. |
| 630 |
|
The imported projections are added to the list and are then available |
| 631 |
|
to the current session and any future Thuban session. |
| 632 |
|
</para> |
| 633 |
|
</section> |
| 634 |
</chapter> |
</chapter> |
| 635 |
|
|
| 636 |
<chapter><title>Table Management</title> |
<chapter><title>Table Management</title> |
| 637 |
<para> |
<para> |
| 638 |
|
Thuban distinguishes two different types of tables: Attribute tables |
| 639 |
|
(which belong to a layer) and usual data tables. Both provide in |
| 640 |
|
general the same functionality with the difference that actions on an |
| 641 |
|
attribute table might also effect the map display. |
| 642 |
|
</para> |
| 643 |
|
|
| 644 |
|
<section><title>Table View</title> |
| 645 |
|
<para> |
| 646 |
|
Thuban provides a standard dialog to display table contents, the |
| 647 |
|
Table View. The view falls into five sections: The title, selections, |
| 648 |
|
the table grid, export functions and the status bar. |
| 649 |
|
</para> |
| 650 |
|
<para> |
| 651 |
|
The title bar identifies the table with it's name. |
| 652 |
|
</para> |
| 653 |
|
<para> |
| 654 |
|
The functions box let the user perform simple analysis on the data |
| 655 |
|
based on comparisons: First choice must be a field identifier of the |
| 656 |
|
table, the second choice determines the type of comparison. The third |
| 657 |
|
choice can be either a specific value (interpreted as numerical |
| 658 |
|
or string depending on the type of the first field) or a second field |
| 659 |
|
identifier. Thus you can perform analysis like selecting all |
| 660 |
|
records where "population > 10000" or |
| 661 |
|
"cars_per_habitants < bike_per_habitants" (note that the field names |
| 662 |
|
are only explanatory, the currently considered dbase files allow only |
| 663 |
|
11 character field names). |
| 664 |
|
|
| 665 |
|
Selections can be combined, either by applying a selection only on |
| 666 |
|
a previously selected set of records or by adding the results of a |
| 667 |
|
selection to a previous set. The default is that a selection replaces |
| 668 |
|
earlier results. |
| 669 |
|
</para> |
| 670 |
|
<para> |
| 671 |
|
The table grid shows the contents of the table (a record per column), |
| 672 |
|
with highlighted selection results. Columns and rows can be resized. |
| 673 |
|
</para> |
| 674 |
|
<para> |
| 675 |
|
The contents of a table can be exported into a file, either dbase |
| 676 |
|
format (DBF) or comma seperated values (CSV). The 'Export' button |
| 677 |
|
raises a file dialog to specify a path and file name, the export type |
| 678 |
|
is determined by the file extension (either .dbf or .csv). |
| 679 |
|
|
| 680 |
|
The 'Export Selection' button works similar but exports only the |
| 681 |
|
selected records. |
| 682 |
|
|
| 683 |
|
The 'Close' button closes the table view. In difference to the |
| 684 |
|
menu item 'Close' just the dialog is closed, the table is still loaded |
| 685 |
|
in Thuban. |
| 686 |
|
</para> |
| 687 |
|
<para> |
| 688 |
|
The status bar displays some statistics about the table and optional |
| 689 |
|
selection results. |
| 690 |
|
</para> |
| 691 |
|
</section> |
| 692 |
|
|
| 693 |
|
<section><title>General Functionality (Menu Table)</title> |
| 694 |
|
<para> |
| 695 |
|
The general functions affect all tables open in Thuban. Attribute |
| 696 |
|
tables are considered as here as usual data tables (with the exception |
| 697 |
|
that they cannot be closed). |
| 698 |
|
</para> |
| 699 |
|
<section><title>Open</title> |
| 700 |
|
<para> |
| 701 |
|
The 'Open' item raises a file dialog to let you select a |
| 702 |
|
dbase file from the file system to be loaded into Thuban read-only. |
| 703 |
|
On OK the selected file is loaded and a table view is opened. |
| 704 |
|
</para> |
| 705 |
|
</section> |
| 706 |
|
|
| 707 |
|
<section><title>Close</title> |
| 708 |
|
<para> |
| 709 |
|
The 'Close' item raises a dialog listing the currently open |
| 710 |
|
data tables (loaded via the 'Open' functionality'). You can select |
| 711 |
|
tables which are dereferenced on confirmation. Since tables are |
| 712 |
|
opened read-only the contents of the tables are not affected. |
| 713 |
|
|
| 714 |
|
A still open table view is closed as well. |
| 715 |
|
|
| 716 |
|
Tables used in a join can not be closed. |
| 717 |
|
</para> |
| 718 |
|
</section> |
| 719 |
|
|
| 720 |
|
<section><title>Rename</title> |
| 721 |
|
<para> |
| 722 |
|
Changes the table title. |
| 723 |
|
</para> |
| 724 |
|
</section> |
| 725 |
|
|
| 726 |
|
<section><title>Show</title> |
| 727 |
|
<para> |
| 728 |
|
The 'Show' item raises a list of available tables (explicitly loaded, attribute tables, results of a join). Selected tables are show in |
| 729 |
|
tables views on 'OK'. |
| 730 |
|
</para> |
| 731 |
|
</section> |
| 732 |
|
|
| 733 |
|
<section><title>Join</title> |
| 734 |
|
<para> |
| 735 |
|
The 'Join' item raises a dialog to specify the two tables to be |
| 736 |
|
joined. The join results in a new table named 'Join of "left table" |
| 737 |
|
and "right table"'. |
| 738 |
|
|
| 739 |
|
The dialog let you select the two tables to be joined and the two |
| 740 |
|
fields the join has to be performed on. By default the new |
| 741 |
|
table contains only those records which are mathced by the join. |
| 742 |
|
|
| 743 |
|
If you want to preserve the records of the left table you can perform |
| 744 |
|
an outer join. The fields from the right table for records not |
| 745 |
|
matched by the join are filled with <varname>None</varname> in this |
| 746 |
|
case. |
| 747 |
|
</para> |
| 748 |
|
</section> |
| 749 |
|
|
| 750 |
|
</section> |
| 751 |
|
<section><title>Attribute Tables</title> |
| 752 |
|
<para> |
| 753 |
|
To clearly separate between both types, Thuban provides functionality |
| 754 |
|
regarding the attribute tables under the Layer menu. |
| 755 |
</para> |
</para> |
| 756 |
|
|
| 757 |
|
<section><title>Show Table</title> |
| 758 |
|
<para> |
| 759 |
|
Opens the attribute table of the currently active layer in a table |
| 760 |
|
view. |
| 761 |
|
|
| 762 |
|
In addition to the functionality described above selections |
| 763 |
|
affect also the map display: objects related to selected records |
| 764 |
|
are highlighted. |
| 765 |
|
</para> |
| 766 |
|
</section> |
| 767 |
|
|
| 768 |
|
<section><title>Join Table</title> |
| 769 |
|
<para> |
| 770 |
|
In difference to the join described above the join results not in a |
| 771 |
|
new table. The attribute table of the currently active layer is the |
| 772 |
|
left table and other tables are join to this table. Results of the |
| 773 |
|
join in turn are available for classifications. |
| 774 |
|
|
| 775 |
|
As a consequence of the above the join cannot result in less |
| 776 |
|
records than the source attribute table. You are warned if the |
| 777 |
|
right table does not fulfill this constraint. Use an outer join |
| 778 |
|
in such cases. |
| 779 |
|
</para> |
| 780 |
|
</section> |
| 781 |
|
|
| 782 |
|
<section><title>Unjoin Table</title> |
| 783 |
|
<para> |
| 784 |
|
As said above, a usual table can not be closed while still used in |
| 785 |
|
a join. While the join table resulting from a join of usual tables |
| 786 |
|
can be simply closed (and therewith dereferences the source tables) |
| 787 |
|
this is not possible for attribute tables. |
| 788 |
|
|
| 789 |
|
Hence joins on attribute tables must be solved explicitely. This is |
| 790 |
|
what the 'Unjoin' item is used for: The last join for the currently |
| 791 |
|
active layer is solved. |
| 792 |
|
</para> |
| 793 |
|
</section> |
| 794 |
|
|
| 795 |
|
</section> |
| 796 |
</chapter> |
</chapter> |
| 797 |
|
|
| 798 |
<chapter><title>Trouble Shooting</title> |
<chapter><title>Trouble Shooting</title> |
| 803 |
<appendix><title>Supported Data Sources</title> |
<appendix><title>Supported Data Sources</title> |
| 804 |
<para> |
<para> |
| 805 |
</para> |
</para> |
| 806 |
|
<variablelist> |
| 807 |
|
<varlistentry> |
| 808 |
|
<term>Shapefile</term> |
| 809 |
|
<listitem><para></para></listitem> |
| 810 |
|
</varlistentry> |
| 811 |
|
|
| 812 |
|
<varlistentry> |
| 813 |
|
<term>DB2 file</term> |
| 814 |
|
<listitem><para></para></listitem> |
| 815 |
|
</varlistentry> |
| 816 |
|
|
| 817 |
|
</variablelist> |
| 818 |
</appendix> |
</appendix> |
| 819 |
|
|
| 820 |
<appendix><title>Supported Projections</title> |
<appendix><title>Supported Projections</title> |
| 821 |
<para> |
<para> |
| 822 |
</para> |
</para> |
| 823 |
|
<variablelist> |
| 824 |
|
<varlistentry> |
| 825 |
|
<term>Geographic</term> |
| 826 |
|
<listitem><para>Geographic</para></listitem> |
| 827 |
|
</varlistentry> |
| 828 |
|
<varlistentry> |
| 829 |
|
<term>Lambert Conic Conformal</term> |
| 830 |
|
<listitem><para>Lambert Conic Conformal</para></listitem> |
| 831 |
|
</varlistentry> |
| 832 |
|
<varlistentry> |
| 833 |
|
<term>Transverse Mercator</term> |
| 834 |
|
<listitem><para>Transverse Mercator</para></listitem> |
| 835 |
|
</varlistentry> |
| 836 |
|
<varlistentry> |
| 837 |
|
<term>Universal Transverse Mercator</term> |
| 838 |
|
<listitem><para>Universal Transverse Mercator</para></listitem> |
| 839 |
|
</varlistentry> |
| 840 |
|
</variablelist> |
| 841 |
</appendix> |
</appendix> |
| 842 |
|
|
| 843 |
</book> |
</book> |
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