Datasheet

ROTATE
The remarkably useful and often overlooked option of ROTATE is Reference. You can
use the Reference option by entering any angle at the keyboard or by picking two points
on the screen. You then type the angle to which you want the selected points to align.
Instead of typing the new angle, you can also make one more selection. It becomes the
second point on a new angle, using the first point selected as a reference for a base point.
SCALE
SCALE also has a Reference option that’s similar to ROTATE’s but that may be even more
useful. I use it frequently to resize an image using a feature on the image that I know the
size of—this can be a photograph of landscape, nautical charts, a mechanical part, or any-
thing else that’s not to scale when inserted. In the example in Figure 1.18, a National
Oceanic and Atmospheric Administration (NOAA) nautical chart has been referenced as
an image. Scaling it using the Reference options involves the following steps:
1. Issue the SCALE command.
2. Select the edge of the image.
3. Give a base point.
4. Type R or use the down arrows to select Reference, as shown.
5. Select a start point. In this example, the latitude line showing 17´ is the first point.
6. Select a second point. In this example, the latitude line showing 18´ is the second
point.
7. Type 1 for one nautical mile, the base unit of this drawing. Because the distance from
17´ to 18´ is one minute of latitude, which represents one nautical mile on the earth,
the image scales correctly.
Figure 1.18
Using the Reference
option of the SCALE
command
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