Appendix A: Functions and Instructions
791
Circle
CATALOG
Circle
x
,
y
,
r
[
,
drawMode
]
Draws a circle with its center at window
coordinates (
x
,
y
) and with a radius of
r
.
x
,
y
, and
r
must be real values.
If
drawMode
= 1, draws the circle (default).
If
drawMode
= 0, turns off the circle.
If
drawMode
= -1, inverts pixels along the circle.
Note
: Regraphing erases all drawn items. See
also
PxlCrcl
.
In a ZoomSqr viewing window:
ZoomSqr:Circle 1,2,3
¸
ClockOff
CATALOG
ClockOff
Turns the clock
OFF
.
ClockOn
CATALOG
ClockOn
Turns the clock
ON
.
ClrDraw
CATALOG
ClrDraw
Clears the Graph screen and resets the
Smart
Graph
feature so that the next time the Graph
screen is displayed, the graph will be redrawn.
While viewing the Graph screen, you can clear all
drawn items (such as lines and points) by
pressing
†
(
ReGraph
) or pressing
ˆ
and
selecting
1:ClrDraw
.
ClrErr
CATALOG
ClrErr
Clears the error status. It sets
errornum
to zero
and clears the internal error context variables.
The
Else
clause of the
Try...EndTry
in the
program should use
ClrErr
or
PassErr
. If the
error is to be processed or ignored, use
ClrErr
. If
what to do with the error is not known, use
PassErr
to send it to the next error handler. If
there are no more pending
Try...EndTry
error
handlers, the error dialog box will be displayed as
normal.
Note:
See also
PassErr
and
Try
.
Program listing:
:clearerr()
:Prgm
:PlotsOff:FnOff:ZoomStd
:For i,0,238
:
@
x
ù
i+xmin
!
xcord
: Try
: PtOn xcord,ln(xcord)
: Else
: If errornum=800 or
errornum=260
Then
: ClrErr
¦
clear the error
: Else
: PassErr
¦
pass on any other
error
: EndIf
: EndTry
:EndFor
:EndPrgm
Summary of Contents for Voyage 200
Page 36: ...Getting Started 36 D B D B Press Result ...
Page 45: ...Getting Started 45 3 0 D B D D B D Press Result ...
Page 46: ...Getting Started 46 D 2 0 0 2 D B Scroll down to October and press Press Result ...
Page 60: ...Getting Started 60 B D Press Result ...
Page 139: ...Previews 139 8 Complete the operation Press 2 d Steps and keystrokes Display 5 f 2 ...
Page 453: ...Differential Equation Graphing 453 ...
Page 468: ...Tables 468 ...
Page 777: ...Activities 777 ...