for the HP 42S
RI - Rational interpolaton

Rational interpolation is suitable for interpolating logarithmic or exponential relations of the data points
e.g. NTC thermistor characteristics than Lagrange interpolation, with its better accuracy and less computational complexity.
Input
Resources to be used
Output

Program list for the HP 42S

RI - Rev.1.10 Sep. 30 2011
00 { 84-Byte Prgm }
01 LBL "RI"
02 ENTER
03 ENTER
04 ENTER
05 RCL 03
06 -
07 ABS
08 X<>Y
09 RCL- 01
10 ABS
11 -
12 CF 01
13 X>0?
14 SF 01
15 R↓
16 RCL- 03
17 RCL 02
18 RCL- 01
19 ×
20 RCL 05
21 RCL- 06
22 ×
23 X<>Y
24 RCL- 01
25 RCL 02
26 RCL- 03
27 ×
28 RCL 05
29 RCL- 04
30 ×
31 FS? 01
32 X<>Y
33 X=0?
34 GTO E
35 ÷
36 X<>Y
37 RCL 06
38 RCL 04
39 FS? 01
40 X<>Y
41 R↑
42 ×
43 LASTX
44 R↓
45 -
46 1
47 R↑
48 -
49 X=0?
50 GTO E
51 ÷
52 RTN
53 LBL E
54 BEEP
55 RTN
56 .END.

Download

'RI' (ri.raw, 87 byte, raw program file for the Free42)

Formulas used

Rational interpolation
rational interpolation

Examples

NoteInterpolation
Common logarithms
Reverse interpolation
Temperature V.S. Resistance characteristic of an NTC thermistor
Operation
2.8 STO 01
3.0 STO 02
3.2 STO 03
0.44715803 STO 04
0.47712125 STO 05
0.50514998 ST0 06
3.1 XEQ RI
12.478 STO 01
 8.068 STO 02
 5.353 STO 03
20 STO 04
30 STO 05
40 STO 06
10.000 XEQ RI
ri ntc
Results
Y: 3.100000000
X: 0.491365525
Y: 10.00000000 
X: 24.94306610 

SEE ALSO

RI - Rational interpolation program for the HP 15C
Online calculator - Rational interpolation and Lagrange interpolation
Ostrowski's method - a root-finding method

www.finetune.co.jp [Mail] Copyright (c) HOSODA Takayuki. All rights reserved.
Powered by
 Finetune