Plus42 Equations, Preview Release

[Massimo Gnerucci]

(12-29-2021 04:36 PM)Thomas Okken Wrote:  

(12-29-2021 02:47 PM)Marco Polo Wrote:  Using latest release, it so impossible to me to delete a (empty) dir: press RMDIR, press soft key with for name, no errors, dir still there.
Am I doing something wrong?

No, you're not doing anything wrong.
Just a minute...

Those were three minutes!

:D

[tommi60]

In Plus42Android.apk (2021-12-29 10:36) when using ASSIGN:

FCN and MEM are switched (when pressing FCN I get MEM and when pressing MEM I get FCN).

[Thomas Okken]

New update:

1. REGS and EQNS now behave in a more legacy-compatible manner: operations on numbered registers succeed, regardless of whether REGS is a local variable, or in the current directory, or in an ancestor directory; the equation editor will update EQNS, also regardless of where it is located; and when REGS or EQNS have to be created, they are created in the root directory.

What this means is that it is still possible to create REGS or EQNS in sub-directories, or even as local variables, and they will work, but by default, the system prefers putting them in the root directory, and there are never any access restrictions.

2. Fixed the FCN/MEM switcheroo during command entry.

[Thomas Okken]

New update:

1. Units now supported in IP, FP, RND, TRUNC / TRN(), ABS, SIGN / SGN(), and INT().

[ggauny@live.fr]

Hi,
Is there exist already a user manual, with examples, for Plus42 1.0. I have some difficulties to understand all things.

For example, how can I do conversion in UNIT subdirectorie of this :
150°C in K. People who have HP48 manual, here in french, see this example in page 194. The answer is 423.15_K.

How have I to do this with PLUS42 1.0 latest version from yesterday ?

Thank in advance.

[Thomas Okken]

(01-03-2022 12:17 PM)ggauny@live.fr Wrote:  For example, how can I do conversion in UNIT subdirectorie of this :
150°C in K. People who have HP48 manual, here in french, see this example in page 194. The answer is 423.15_K.

How have I to do this with PLUS42 1.0 latest version from yesterday ?

In Plus42, you can't convert using Left Shift + Unit, since there is only one Shift key, and that is already used to divide by units. Instead, you can convert by adding 0 with the desired unit attached: 150_°C 0_K + → 423.15_K.

Note that until now, adding °C or °F and a different temperature unit was not allowed; I copied this restriction from the HP-48G. However, I just decided that that restriction isn't actually useful, and removed it, so now the trick of converting to unit xyz by adding 0_xyz works for all units. See my next post...

[Thomas Okken]

New update:

1. Adding °C or °F to other temperature units used to be forbidden; it is now allowed.
2. MOD now works with units.
3. Added RENAME function for directories. RENAME "foo" renames the directory currently named "foo", taking the new name from the ALPHA register.

[ggauny@live.fr]

Thank you for your help.

[Marco Polo]

(01-03-2022 04:25 PM)Thomas Okken Wrote:  [quote='ggauny@live.fr' pid='156128' dateline='1641212268']
Note that until now, adding °C or °F and a different temperature unit was not allowed; I copied this restriction from the HP-48G. However, I just decided that that restriction isn't actually useful, and removed it, so now the trick of converting to unit xyz by adding 0_xyz works for all units. See my next post...

The reason for such operation being forbidden in 48/50 resides in ease of user errors when calculating temperature difference between different scales.
For such reason the function TDELTA was provided, first in Equation Library Card (48sx) then directly (48g/gx).

[Thomas Okken]

It looks like TDELTA on the 48G is equivalent to X<>Y − +/− in Plus42.

[Thomas Okken]

New update:

(Re-update, the one a few minutes ago had a nasty bug, program copying didn't work...)

1. Directory, program, and variable management.

In the DIRS catalog, Shift plus a directory item now generates a reference object, pointing to the directory, program, or variable represented by the item. Doing this multiple times causes these references to be collected in a list. You can remove an item from a list by selecting it again. Or you can move between directories, and compile a list of objects across multiple directories.

These reference objects, and lists containing only reference objects, serve only one purpose: they can be fed to the new REFMOVE, REFCOPY, and REFFIND functions.

REFMOVE moves the referenced objects into the current directory. In case of a list, the objects are added in the order in which they appear in the list, and they are added in front of the already existing objects. Note that it is possible to move objects within a directory as well, which can be useful if you want to change the order in which they appear in the catalogs.

REFCOPY works like REFMOVE, except it copies items instead of moving them. However, directories and variables within the current directory are never copied, always just moved. (Programs are copied.)

Finally, REFFIND finds the real object referenced by the reference in X. (This only works when X contains a single reference object, not a list.) It changes to the referenced directory, and moves to the referenced program or VIEWs the referenced variable.

For convenience, the REFMOVE, REFCOPY, and REFFIND commands are mapped to the keyboard when objects of the appropriate types are in the X register; REFMOVE is [−], REFCOPY is [×], and REFFIND is [÷].

2. In RUN mode, when there is a string or a list in the Y register, the [+] key now performs APPEND.

[Thomas Okken]

Forgot to mention in my previous post:

3. →LIST and LIST→ functions. →LIST takes a count n from X and creates a list with n elements, taken from Y and up (levels 2 to n+1). And LIST→ performs the opposite operation. Naturally, these functions will be useful primarily in NSTK mode, since in 4STK mode they are limited to lists with 3 elements or less.

(These functions will also be in the next Free42 release, as will the APPEND mapping to the [+] key I mentioned in my previous post. This is general purpose list functionality that seems appropriate in both apps.)

[Thomas Okken]

New update:

1. Fixed a couple of crashes involving deeply nested subroutine calls. Note that this does not affect Free42, even though Free42 has the deep RTN stack as well; these bugs were related to the changes needed to support directories.
2. In PRGM mode, when the program is not in the current directory (which you can tell by the triangular pointer to the current line being hollow instead of solid black), GTO .. now sets the current directory to the program's directory.
3. Regression in the equation parser: it should accept both period and comma as the decimal, and ignore flag 28, but it didn't. Fixed.
4. CATALOG now has a new OTHER section, which is where it shows unit and reference objects. Note that units were formerly shown in the REAL section, but that was a bit problematic, in that the REAL section is used for command entry menus where only real and string values are acceptable, like indirect addressing, and having other types show up there was annoying.

[Thomas Okken]

New update:

1. PATH variable. You can create a list named PATH, stored in the root directory, to provide a search path for programs and variables. You store directory references in PATH (see here). The directories referenced by PATH are searched after the current directory and its ancestors.
2. Command completion menus now show variables and programs from ancestor directories and PATH. Items from the current directory are shown in white text on black buttons, as usual; items from ancestor directories and PATH are shown in black on white. For operations that modify their operands, only the contents of the current directory are shown.

Many, many changes in the code. Use with caution; back up your state files!

[ggauny@live.fr]

Hi,

In DISP, when I press RADIX , I get . in the screen and when I press . in RADIX I get ,

I have the latest version with many, many changes in the code.

[Thomas Okken]

Are you sure you are looking at a number with a decimal in it? If you're looking at, say, 1000 in ALL mode, you would see 1,000 in RDX. mode and 1.000 in RDX, mode.

[ggauny@live.fr]

Hi,

My fault, I beg apolozises.

[ggauny@live.fr]

Hi,

Of course you know that 'SIGN' is not very good, in HP 41 too.
If x=0, SIGN give 1, best is 0. Very easy to correction with a test :

x=0
x!=0 ?
SIGN
.
.
.
May be have you in mind to do directely : 0 SIGN give 0 ?

Good day.

[Massimo Gnerucci]

On the 41 SIGN returns 0 to X if the value in X is ALPHA characters.

On the 42 SIGN returns 0 to X if the value in X is not a number.

[Thomas Okken]

The HP-41C manual even mentions using SIGN to recognize strings. The 42S has the STR? function for that purpose, but still has SIGN return 1 for X=0 and 0 for strings, for backward compatibility with the 41.

In the equation compiler in Plus42, I made SGN() 17B-compatible by generating REAL? X≠0? SIGN. For complex arguments, SIGN works like UVEC, and this way, I was able to keep that behavior, while only working around the special case for real numbers equal to zero.