The Absolute Direction Instruction, Di - HP 7470A Interfacing And Programming Manual

The Absolute Direction Instruction, DI
DESCRIPTION The absolute direction instruction, DI, specifies the
direction in which characters are lettered.
The instruction can be used to change the direction of labeling
to a new absolute direction; by absolute we mean independent of P1,P2
settings. It is especially useful for labeling a Y-axis or labeling a
vertical graph.
SYNTAX DI run, rise terminator
or
DI terminator
EXPLANATIONRun and rise are in decimal format, 0 to :127.9999,
and specify the direction according to the relationship:
rise
6= tan'1(—-­
run
where:
rise = SIN (0)
run = COS (9)
At least one parameter must be effectively nonzero, i.e., I2 0.0004I.
A DI command with a rise parameter of zero will produce horizontal
labeling. A DI command with a run parameter of zero will produce
vertical labeling.
A DI command with no parameters will default to the values DI 1,0
(horizontal). A DI command with only one or more than two parameters
will set an error condition and the instruction will be ignored.
A change in the orientation of P1 and P2 will not affect the direction of
labeling. A DI command remains in effect until another DI, DR, IN, or
DF command is executed, or the plotter is initialized from the front
panel.
A DI command updates the carriage-return point to the current pen
position.
When the angle, 0, necessary to establish the desired label direction is
known, the command DI cos6, sin6 can be used to establish label
direction.
5-10 LABELING