Specifications
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3. Text
To print the word “house”, if you write:
print house
LOGO sees the word “house” as a command. To enable LOGO to treat the word
“house” as text, there must be double quote marks placed immediately before and
after it. It should be written as
print "house"
4. Variable name
Placing a colon “:” before a word enables LOGO to read the word as a variable. In
the example above, “forward :n” enables LOGO to read “:n” as a variable and use
it as input to the command “forward.”
1. Drawing Commands
forward (fd) n turtle goes forward N steps.
back (bk) n turtle goes back N steps.
left (lt) n rotate the turtle left (counterclockwise) N degrees.
right (rt) n rotate the turtle right (clockwise) N degrees.
setx n turtle goes to X = N coordinate.
sety n turtle goes to Y = N coordinate.
setxy x y turtle goes to (x,y) coordinate.
setheading (seth) n turn the turtle N degrees (clockwise) from the straight
up position.
setpc n set pen colour to N(N = 0~3). (0=white, 1=lightgrey,
2=dark grey, 3=black).
setbg n set background colour to N(N = 0~3). (0=white, 1=lightgrey,
2=dark grey, 3=black).
pencolour (pc) get current colour N of pen(N=0~3). (0=white,1=lightgrey,
2=dark grey, 3=black).
background (bg) get current background colour N (N=0~3).(0=white,
1=lightgrey, 2=dark grey, 3=black).
penup (pu) put the turtle’s pen up. When the turtle moves, it does
not draw a line.
pendown (pd) put the turtle’s pen down and draws a line when the
turtle moves.(default status)
showturtle (st) make the turtle shape visible.(default status)
hideturtle (ht) make the turtle shape invisible.
home move the turtle to the center of the screen, points the
turtle straight up (HEADING 0), but does not clear the
graphics screen or alter the pen state.
clearscreen (cs) erase the graphics screen, returns the turtle to the center
of the screen, and sets the turtle’s heading to 0.
CLEARSCREEN does not affect the pen state or screen
colours.
xcor output the X coordinate of the turtle.
ycor output the Y coordinate of the turtle.
heading output the turtle’s degree.
34200Manual 2/28/00, 10:01 AM28