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h2. Introduction

!att:_img_gen^axes_annotation_scalebar.png|border=1,width=800!
_Example of a scene with axes, annotation and scalebar_

Geographical grids, axes annotation, scalebars and text are natural display features when working out displays and presentation graphics. This chapter gives a brief documentation of the standard menus for text and annotation graphics in the system.
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*On this page:*
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h2. Geographical coordinates with axes

Use the command *Geographical coordinates* to display axes and coordinate annotation on a dataset.

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Geographical coordinates can be accessed as a command (found in *Shared Commands > Visualization*) or as a stand alone menu from *Tools > Geographical Management*. In either case the rules for a correct display is the same.

* Push *Default display* (older version only *Display*) under *Default display* to see the default values.
* Type in *Longitude/Latitude start*, *Long/Lat increment* and *Longitude/Latitude stop* values to set a custom geographical grid.
* Push *Display* or *Execute* to display geographical coordinates using the Lat / Lon values.
* To get a nice placement of the annotation numbers use the tuning in *Adjust annotation numbers*.

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Sometimes it may be useful to create an item command that will save your settings for a specific dataset. This will save you time next time you want to display axes over the same area. Read more about [creating item commands|Customizing the Interface#Creating item commands].
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h3. Options in Geographical coordinates
The menu was updated with a new *Help* text:
{note:title=Help text on Geographical coordinates menu}

	*Guide to display geographical coordinates*
	
	Use this command object to display a Lat / Lon grid.
	
	The first thing to do is to check that the correct *coordinate system* is set under the *Coordinates* page.
	When this is done and correct go on to get a *default display* of geographical coordinates.
	
	Push first *Default display* to get a default display as good as possible. Sometimes the algorithm get a good display,
	but normally the user must take care of the *detailed settings* of *start, increment and stop* position.
	
	Push *Update detailed* to get the Lat / Lon values into the number fields and tune them for a satisfactory display.

	When pushing *Display* or *Execute* the display of geographical coordinates will use the Lat / Lon values.
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*Here is a little study of display options and how to get a good display.*

A part of the *Atlantis* project is used to display a map and geographical coordinates. The assumed projection is *Mercator*, but we will also study the display when assuming other projections.

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!att:_img_gen^gc_defdis.png!
The default display for *Mercator* appears OK, but can be improved. Push *Update detailed* to transfer default values over to the Lat / Lon fields.
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!att:_img_gen^gc_adjust1.png!
Use *Adjust annotation numbers* to get a better positions of the coordinate numbers. Here the _right_ number was adjusted to -25 and _Up_ to 5. The *Longitude start, increment, stop* is *-14  2  0*. The *Latitude start, increment, stop* is *-34  2  24*. 
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!att:_img_gen^gc_adjust2.png!
To display annotation numbers for every line change the number next to *Auto annotation* with the tooltip *Frequence of annotation number* to 1.
We see that the minutes are zero and change *Annotation format* to *DD* (Only degrees). At the same we check in for *E/W/N/S*. 
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!att:_img_gen^gc_adjust3.png!
If the coordinate system was *UTM zone 32 Northen Hemisphere* the display lines are more slanted. This shows that correct coordinate setting is essential for getting a correct display.

The geographical lines was displayed using *Default display*, but kept the same *adjustments of annotation numbers* as before.
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!att:_img_gen^gc_adjust4.png!
To get annotation display along all side change default *NE* to *all*. For a little display like this it is necessay to adjust all numbers. This particular setting was *-25 50 5 -20* for *Right Left Up Down*.
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!att:_img_gen^gc_persp.png!
To get the coordinate lines displayed on the surface one has to check in the *Sticky* checkbox and also apply *Set as sticky surface* on the surface grid. 
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h2. Scale bar

To display a scale bar open *Tools > Scalebar display*

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* Push *Draw Scalebar* to display the scalebar in default position and appearance.
* To place the scalebar at specific position:
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# Set the screen in 2D mode.
# Tick the box *Use XYZ coordinates*
# Click in the graphic window where you want to place the scalebar.
# Click *Update cursor to world coordinates* to get the cursor coordinates.
# Redisplay scalebar by pushing *Draw Scalebar*
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h2. Text annotation

The *Three dimensional text* command lets you create text annotation anywhere in the graphical window. You can create 2D or 3D text, display the text in any angle or stick the text to a surface. All these things can be found out whith a little test and trying. When everything is fine save the command object. Optionally save it as an *Item command* or copy a present CO so you work with and save a copy of the command object.

!att:_img_gen^annotation.png|width=900!

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As an example here are the guide lines for drawing a text at an angle along a line.

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* Write in the desired text in the *text field*.
* Set the screen in 2D mode and make two cursor positions:
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# First cursor position: *at end of text*
# Second cursor position: *at start of text*
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* If the screen is in 3D mode use *y* to attach the cursor point to a surface.
* Push *Update cursor to coordinates*.
* Push *Update dip and azimuth*. *Azimuth* is for rotation around z axes. *Dip* is for 3D mode.
* Check in the *Dip* and *Azimuth* boxes.
* Select text attributes.
* Push *Execute* to display the text.
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With a little training one can place text at any angle and position.
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!att:_img_gen^geocoord2.png|width=400!
_Example map with geo grid, scale bar end 3D text_
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