Threaded Mode | Linear Mode

Eddie W. Shore · 02-18-2019, 05:04 AM

The program FTAB uses the function defined in FX, with variable “X” to generate a 2 column matrix of f(X). The matrix is stored in variable MATS. The program ends with MATS in edit mode, so you see all the points generated. Use the soft key [ → ] to view the entries.

Setting up FX

To set up the function FX, the program needs to be in the following format:

Code:

00 {nnn-Byte Prgm}

01 LBL “FX”

02 MVAR “X”

03 f(X) starts here, use RCL “X” for X

…

nn-1 RTN

nn END

HP 42S Program FTAB
HP 42S, DM 42, Free42

Code:

00 { 99-Byte Prgm }

01▸LBL "FTAB"

02 "X Start:"

03 PROMPT

04 STO 01

05 "X Step:"

06 PROMPT

07 STO 02

08 "# Steps:"

09 PROMPT

10 STO 03

11 1

12 -

13 1ᴇ3

14 ÷

15 STO 04

16 RCL 03

17 2

18 DIM "MATF"

19 INDEX "MATF"

20▸LBL 00

21 RCL 01

22 RCL 04

23 IP

24 RCL× 02

25 +

26 STO "X"

27 STOEL

28 J+

29 XEQ "FX"

30 STOEL

31 J-

32 I+

33 ISG 04

34 GTO 00

35 EDITN "MATF"

36 .END.

Example

f(x) = x^2 * e^x

FX:

Code:

00 { 18-Byte Prgm }

01▸LBL "FX"

02 MVAR "X"

03 RCL "X"

04 ENTER

05 X↑2

06 X<>Y

07 E↑X

08 ×

09 RTN

10 .END.

Input:
X Start: 0
X Step: 0.5
# Steps: 10

Result Matrix MATS:

Code:

MATF=    [ 10x2 Matrix ]

1=              0.0000

2=              0.0000

1=              0.1000

2=              0.0111

1=              0.2000

2=              0.0489

1=              0.3000

2=              0.1215

1=              0.4000

2=              0.2387

1=              0.5000

2=              0.4122

1=              0.6000

2=              0.6560

1=              0.7000

2=              0.9867

1=              0.8000

2=              1.4243

1=             0.9000

2=             1.9923

Link: https://edspi31415.blogspot.com/2019/02/...table.html