Page 22-25
Data set 1
Data set 2
x y
x y
0.4 6.3
0.7 4.8
1.0 4.9
1.0 3.0
2.0 4.3
1.5 2.0
3.4 3.0
2.2 0.9
4.0 1.2
3.5 0.4
5.8 2.0
4.5 1.0
7.2 3.8
5.0 2.0
7.8 5.3
6.0 2.5
9.0 7.2
7.1 2.0
8.0
0.7
9.0
0.0
10.0
1.5
10.5
3.4
11.0
5.0
Note
: The program FRAME, as originally programmed (see diskette or CD
ROM), does not maintain the proper scaling of the graph. If you want to
maintain proper scaling, replace FRAME with the following program:
«
STO
Σ
MIN
Σ
MAX
Σ
2 COL
DUP
COL DROP – AXL ABS AXL 20
/ DUP NEG SWAP 2 COL
+
ROW DROP SWAP
yR xR
«
131
DUP R
B SWAP yR OBJ
DROP – xR OBJ
DROP - / * FLOOR
R
B PDIM yR OBJ
DROP YRNG xR OBJ
DROP XRNG ERASE
»
»
This program keeps the width of the PICT variable at 131 pixels – the
minimum pixel size for the horizontal axis – and adjusts the number of pixels
in the vertical axes so that a 1:1 scale is maintained between the vertical and
horizontal axes.
Pixel coordinates
The figure below shows the graphic coordinates for the typical (minimum)
screen of 131
×
64 pixels. Pixels coordinates are measured from the top left
corner of the screen {# 0h # 0h}, which corresponds to user-defined
coordinates (x
min
, y
max
). The maximum coordinates in terms of pixels
