Zooming in and out in the graphics display
Whenever you produce a two-dimensional FUNCTION graphic interactively,
the first soft-menu key, labeled @) Z OOM, lets you access functions that can be
used to zoom in and out in the current graphics display.
The ZOOM menu
includes the following functions (press Lto move to the next menu):
We present each of these functions following. You just need to produce a
graph as indicated in Chapter 12, or with one of the programs listed earlier
in this Chapter.
ZFACT, ZIN, ZOUT, and ZLAST
Pressing @) Z FACT produces an input screen that allows you to change the current
X- and Y-Factors. The X- and Y-Factors relate the horizontal and vertical user-
defined unit ranges to their corresponding pixel ranges.
Change the H-
Factor to read 8., and press @@@OK@@@, then change the V-Factor to read 2., and
press @@@OK@@. Check off the option
Recenter on cursor, and press @@@OK@@.
Back in the graphics display, press @@ZIN@ . The graphic is re-drawn with the
new vertical and horizontal scale factors, centered at the position where the
cursor was located, while maintaining the original PICT size (i.e., the original
number of pixels in both directions).
Using the arrow keys, scroll
horizontally or vertically as far as you can of the zoomed-in graph.
To zoom out, subjected to the H- and V-Factors set with ZFACT, press @) Z OOM
@ZOUT. The resulting graph will provide more detail than the zoomed-in graph.
You can always return to the very last zoom window by using @ZLAST.