Search found 143 matches

by whuyse
Thu May 06, 2021 1:39 pm
Forum: Usage tips, tricks and problem reports
Topic: DM42 resets during program run
Replies: 16
Views: 2640

Re: DM42 resets during program run

Yes for this program Runge–Kutta methods would have worked. Many thanks to Jean-Marc Baillard and to Angel Martin for massive, well-documented contributions (ie. Elliptic Functions ROM). Don't know how they do it. But my progression through the solar system n-body problem is to progressively add bo...
by whuyse
Fri Apr 30, 2021 1:20 pm
Forum: Usage tips, tricks and problem reports
Topic: DM42 resets during program run
Replies: 16
Views: 2640

Re: DM42 resets during program run

BTW, solving the orbital equations using my Cash-Karp Runge-Kutta ODE program (not yet published.. will come), it seems the orbital period should be 73 seconds shorter. I needed only 1000 sample points to get 10 accurate digits, 29 seconds on my USB-DM42. in: t: 0 w: [ (363228900,0) (0,1082) ] STEP:...
by whuyse
Fri Apr 30, 2021 8:08 am
Forum: Usage tips, tricks and problem reports
Topic: free42 3.01 new comparison functions
Replies: 6
Views: 1154

Re: free42 3.01 new comparison functions

I just read the release notes of v3.0.3, a couple of nice surprises there, Thomas! - INDEXing a local matrix, and returning to a previously indexed one when the function returns - RTNERR that accepts a string, and ERRNO and ERRMSG - these were in my 'err handling improvements' list. Thanks! Here's t...
by whuyse
Wed Apr 28, 2021 9:05 am
Forum: Software Library
Topic: My 42s software collection update
Replies: 7
Views: 1479

Re: My 42s software collection update

Why not, after DIM "_M": (to n x n+1)

Code: Select all

 RCL "_M"
 TRANS
 STO "_M" @ diag is now first row
 1
 R^ @ we are in 4STK mode ;-)
 DIM "_M"
 RSUM
Cheers, Werner
by whuyse
Tue Apr 27, 2021 6:19 pm
Forum: Software Library
Topic: My 42s software collection update
Replies: 7
Views: 1479

Re: My 42s software collection update

richmit wrote:
Tue Apr 27, 2021 5:58 pm
What is the - for on line 17?
Can I use this code or is it copyrighted?
The ‘-‘ is to drop the stack so that the original y and z are preserved.
Feel free to use it, of course!

Cheers, Werner
by whuyse
Tue Apr 27, 2021 2:16 pm
Forum: Software Library
Topic: My 42s software collection update
Replies: 7
Views: 1479

Re: My 42s software collection update

Very nice documentation! To create an identity matrix, and a diagonal matrix from a vector without looping or matrix access: 00 { 49-Byte Prgm } 01▸LBL "IDN" 02 1 03 NEWMAT 04 SIGN 05▸LBL "DIAG" 06 LSTO "." 07 DIM? 08 + 09 ENTER 10 DSE ST X 11 DIM "." 12 X<> &...
by whuyse
Tue Apr 27, 2021 10:38 am
Forum: Usage tips, tricks and problem reports
Topic: DM42 resets during program run
Replies: 16
Views: 2640

Re: DM42 resets during program run

readable listing: 00 { 174-Byte Prgm } 01▸LBL "SOrbit" 02 363228900 03 STO 04 04 1082 05 STO 07 06 0 07 STO 05 08 STO 06 09 STO 10 10 "Delta T" 11 PROMPT 12 STO 08 13 "T Max" 14 PROMPT 15 STO 09 @ @ main loop 16▸LBL 01 17 RCL 08 18 STO+ 10 19 RCL 09 20 RCL 10 21 X>Y? 22...
by whuyse
Fri Apr 23, 2021 8:51 pm
Forum: Usage tips, tricks and problem reports
Topic: How to use PGMMENU & VARMENU
Replies: 14
Views: 2536

Re: How to use PGMMENU & VARMENU

I meant: when, in the integration menu, you do not select a variable of integration but EXIT instead, it does not clear the alpha register.
Cheers, Werner
by whuyse
Fri Apr 23, 2021 2:51 pm
Forum: Usage tips, tricks and problem reports
Topic: How to use PGMMENU & VARMENU
Replies: 14
Views: 2536

Re: How to use PGMMENU & VARMENU

A VARMENU1 function that acted the way the integration variable menu works would be a neat feature. Actually, in that integration menu, there's another behaviour I'd like to see in VARMENU1: catch EXIT. In the integration menu, pressing EXIT repeatedly will cycle back through the respective menus (...
by whuyse
Thu Apr 22, 2021 2:12 pm
Forum: Usage tips, tricks and questions
Topic: DM15L FIX, SCI,ENG, ALL ?
Replies: 3
Views: 1480

Re: DM15L FIX, SCI,ENG, ALL ?

No it isn't. ALL does not show trailing 0's.
Cheers, Werner