Search found 42 matches

by whuyse
Sun Nov 10, 2019 9:52 pm
Forum: Software Library
Topic: User Flag Catalog
Replies: 4
Views: 408

Re: User Flag Catalog

in Free42 (and the DM42) you can store up to 14 characters per register instead of only 6, using the following utilities to transform up to 14 characters to the X register (A2X) and its inverse (X2A) 00 { 77-Byte Prgm } 01>LBL "A2X" 02 ALENG 03 14 04 X>Y? 05 X<>Y 06 25600 07 0 08>LBL 03 09 % 10 ATOX...
by whuyse
Fri Oct 04, 2019 8:54 am
Forum: Software Library
Topic: Graphics utilities: H/V lines, grids and tiles
Replies: 3
Views: 1083

Re: Graphics utilities: H/V lines, grids and tiles

It’s a printout from the Dm42 itself, not compatible with the program import. To import, use the .raw file.
Cheers, Werner
by whuyse
Tue Sep 24, 2019 3:18 pm
Forum: Software Library
Topic: Graphics utilities: H/V lines, grids and tiles
Replies: 3
Views: 1083

Graphics utilities: H/V lines, grids and tiles

0. Abstract My ultimate goal is to draw a chess board. To achieve this in a modular fashion, we'll need tools to draw lines horizontally and vertically, use these to draw a grid, and then be able to fill half of the grid cells with a shading pattern. So, without further ado: 1. HLINE X Y Z T In: n ...
by whuyse
Fri May 17, 2019 10:16 am
Forum: Discuss!
Topic: Precision of the Exponential Integral on DM42
Replies: 1
Views: 840

Re: Precision of the Exponential Integral on DM42

Show us your code, please? And that site will simply use N+k-digit arithmetic and constants to get to the precision requested (N) ie. they'll use gamma to N+k digits to guarantee the result is accurate to N digits. eg. for x=-30 the largest summation term is about 2.7e10 so an extra 10 or 11 digits ...
by whuyse
Thu Feb 28, 2019 2:36 pm
Forum: DM42
Topic: Looking forward to the DM42 update utilizing the Free42 2.023 update...
Replies: 29
Views: 4324

Re: Looking forward to the DM42 update utilizing the Free42 2.023 update...

in my second-to-last post, 'extended precision' was but an example ;-) - that's why I said 'i.a.' - it's the resulting accuracy that counts.
And yes, all of that applies to the complex case as well. A DOT product of 2 complex vectors is obtained using 4 real dot products.
Cheers, Werner
by whuyse
Thu Feb 28, 2019 2:11 pm
Forum: DM42
Topic: Looking forward to the DM42 update utilizing the Free42 2.023 update...
Replies: 29
Views: 4324

Re: Looking forward to the DM42 update utilizing the Free42 2.023 update...

We spoke of this before, can't remember whether it was here or at the hpmuseum.
There is a way to use FMAs to implement dot products, and obtain a result that is as accurate as if you used double precision.
I'll see if I can find it again,
Werner
by whuyse
Thu Feb 28, 2019 11:00 am
Forum: DM42
Topic: Looking forward to the DM42 update utilizing the Free42 2.023 update...
Replies: 29
Views: 4324

Re: Looking forward to the DM42 update utilizing the Free42 2.023 update...

Werner, do you know exactly which functions in the HP-42S use special-case logic for 2x2 matrices? I know DET does - it simply evaluates ab-cd in 15-digit precision. The others, I'll perform some tests. And what about higher-precision dot products? Obviously DOT, but matrix-matrix multiplication is...
by whuyse
Wed Feb 13, 2019 9:18 am
Forum: DM42
Topic: Looking forward to the DM42 update utilizing the Free42 2.023 update...
Replies: 29
Views: 4324

Re: Looking forward to the DM42 update utilizing the Free42 2.023 update...

Thomas Okken wrote:
Tue Feb 12, 2019 10:58 am
  • More accurate 2x2 matrix operations
  • More accurate dot product using FMA
Yes!!! As this is something the real 42S does, as well (albeit not with FMAs)
Cheers, Werner
by whuyse
Sat Feb 02, 2019 10:01 am
Forum: Usage tips, tricks and problem reports
Topic: The Stack (according to Free42 Manual)
Replies: 19
Views: 2177

Re: The Stack (according to Free42 Manual)

Perhaps you should read the first post in this thread before replying.. ;-)
This is about RPN on the DM42, and of course Joe's remarks are also entirely accurate, as usual.
(well, except for Z=9 which should've been T=9 ;-)

Cheers, Werner
by whuyse
Wed Jan 30, 2019 12:20 pm
Forum: Usage tips, tricks and problem reports
Topic: newbie and coding help needed
Replies: 6
Views: 1041

Re: newbie and coding help needed

Just for completeness: the GETKEY approach does work, but it doesn't catch EXIT or the new softkeys. This is what I used to try it out, with the up/down arrow keys and S+ for left and XEQ to go right: 00 { 48-Byte Prgm } 01▸LBL "TRY" 02 CLLCD 03 1 04 ENTER 05 "×" 06▸LBL 10 07 AGRAPH 08 GETKEY 09 R↓ ...