0.9.0 - complex numbers

• 0.9.0 (2024-01-06)
  • Breaking: Change names and internal formats of various appVars
    • STK list variable replaced with RPN83STK
    • REGS list variable replaced with RPN83REG
    • RPN83SAV remains unchanged
    • the old STK and REGS variables can be manually removed
    • see TI-OS Interaction for more
      details
  • Breaking: Add CPLX menu at the previous location of CONV
    • CPLX menu seemed most convenient on row 1 of the ROOT menu where
      the old CONV was located
    • CONV got pushed to row 2, where the UNIT menu was previously
      located
    • UNIT got pushed to row 3, into an empty slot
    • the RPN83P home menu row now has exactly the same items as the MATH
      menu on the TI-OS:
      • RPN83P: MATH, NUM, PROB, CPLX
      • TI-OS: MATH, NUM, CPX, PROB
  • Support more than 14 digits during edit/input
    • When more than 14 digits are entered, the left most digits scroll off
      to the left, with the left most digit replaced with an ellipsis
      character indicates existence of extra digits.
    • Normal mode:
      • accepts maximum of 20 digits, which supports entering all 14
        digits encoded by the TI-OS floating point number format
    • Complex mode:
      • accepts maximum of 41 digits to allow 2 floating point numbers
    • BASE BIN mode
      • accepts up to 32 digits, to allow a 32-bit binary number when the
        WSIZ is 32.
    • see Input Limits and Long
      Numbers for more
      details
  • PROB
    • Expand range of COMB(n,r) and PERM(n,r) arguments to n,r<=65535
      from n,r<=255.
    • Improve performance of COMB(n,r) when r>(n-r) by taking advantage
      of the symmetry of COMB(n,r)==COMB(n,n-r).
    • Eliminate floating point round-off errors in computing COMB(n,r) by
      incrementing the divisor from 1 to r, instead of decrementing it
      from r to 1.
  • Complex Numbers
    • redesign RPN stack and storage registers to support both real and
      complex numbers
    • extend arithmetic, algebraic, transcendental handlers to support
      complex numbers
    • add explicit CPLX menu group with: REAL, IMAG, CONJ, CABS, CANG
    • support RRES (real result) and CRES (complex result) menu settings
    • support RECT (rectangular), PRAD (polar radian), PDEG (polar degree)
      menu settings
    • display complex numbers in RPN stack in rect and polar modes
    • support complex numbers in SHOW in rect and polar modes
    • support Linking/Unlinking a complex number and its 2 real components
      using 2ND LINK (equivalent to COMPLEX button on the HP-42S)
    • support entry of complex numbers on a single line in RECT, PRAD, and
      PDEG modes using the 2ND i and 2ND ANGLE keys.
    • see Complex Numbers for more
      details.
  • Save and restore app MODE settings independently from the TI-OS settings
    • decouple the TI-OS MODE settings from the RPN83P MODE settings
    • the TI-OS MODE settings are saved upon app start, and restored upon
      app exit
    • the app MODE settings are saved and restore independently
    • for example, it is now possible to set the TI-OS to FIX(2) and DEG,
      while setting RPN83P to SCI(4) and RAD and the 2 settings are managed
      separately, even though there is only a single set of global OS
      settings
  • Bug Fix: Render 3-digit EE exponents correctly in SHOW mode.
    • 3-digit exponents can only be shown for complex numbers, so the bug
      was latent until complex numbers were added
  • Bug Fix: Fix overflow in rectangular to polar conversion >POL
    • the built-in TI-OS RToP() function has a bug which throws an
      exception when x^2+y^2 becomes >=1e100, which can happen for x
      or y as low as 7.07e49.
    • reimplement using a custom rectToPolar() without the scaling bug

0.8.0 - increase performance by 2.5X on 83+SE/84+/84+SE; add SHOW command

• 0.8.0 (2023-12-03)
  • Breaking: Flip the order of polar-rectangular conversion menu function
    (>POL and >REC) so that they are consistent with the HP-42S. I don't
    know why I had them reversed.
    • Y register holds the y or theta value, entered first, and
    • X register holds the x or r value, entered second.
  • Breaking: Flip the order of (X, Y) coordinates of the ATN2 menu
    function, so that they are consistent with the >POL function.
    • Y register holds the y value, which is entered first, then
    • X register holds the x value, which is entered second.
  • Breaking: Change WSIZ to prompt the user for the base word size
    using WSIZ _ _ prompt, instead of using the value in the X register.
    • Solves a major usability problem where the user was forced to enter
      the word size using the currently selected base mode (e.g. HEX or
      BIN). For example, the word size 16 was required to be entered as
      10000 in BIN mode, which was too confusing.
    • See Base Word Size for more details.
  • Bug Fix: Tweak the stack-lift logic so that certain operations
    (RollDown, RollUp, X<>Y) enable stack lift even if the previous command
    was a CLEAR or CLX.
    • The rpnFlagsLiftEnabled was not set properly for RollDown, RollUp,
      X<>Y and potentially other commands.
    • So a CLEAR RollDown RollDown RollDown RollDown followed by a number
      would overwrite the X register, instead of doing a stack lift.
  • Increase execution speed by 2.5X on 83+SE, 84+, 84+SE
    • set CPU speed to 15 MHz when supported by hardware
    • remain at 6 MHz on the 83+
  • SHOW display mode
    • implement "Show" function using 2ND ENTRY on TI keyboard
    • displays all 14 internal digits of the TI-OS floating point number
      • if integer < 10^14: display as integer
      • otherwise: display in scientific notation
    • BASE mode variation
      • BIN mode: display WSIZ digits in groups of 4, using up to 4
        display lines
      • all other BASE modes: display underlying floating point number
    • see SHOW Mode for details
  • BASE input limit
    • limit the number of digits that can be entered in BASE mode to a
      maximum that is appropriate for the selected WSIZ and the baseNumber
      selected by HEX, DEC, OCT and BIN
    • for example, selecting HEX and WSIZ 16 will allow only 4 hex
      digits to be entered
    • see Base Input Digit Limit for
      details
  • HELP pages
    • Add page for CONV functions to show order of (x, y, r, theta)
      variables on RPN stack
    • Add page for STAT functions
    • Add page for NUM functions
    • Add page for various display MODEs

0.7.0 - time value of money (TVM); multiple BASE word sizes

• 0.7.0 (2023-11-20)
  • STAT
    • fix broken Sigma+ and Sigma- when Y==0
    • use alternate equation for SLOP (slope) which works when the Y
      data points are the same
    • fix "stack lift disable" feature of Sigma+ and Sigma- which
      probably got broken during an earlier refactoring
    • check for division by zero when calculating weighted mean WMN, and
      show 9.9999999999999E99 to indicate error, allowing weightedX (or
      weightedY) to be evaluated even if the other is undefined
  • BASE
    • implement WSIZ (set word size) restricted to 8, 16, 24, and 32
      (inspired by HP-16C and Free42)
    • display appropriate number of digits for various WSIZ values, for
      various base modes (HEX, OCT, BIN)
    • display ellipsis character on left most digit in BIN mode if
      the binary number cannot be fully displayed using 14 digits on the
      screen
    • Breaking Change: change order of BDIV results in X and Y
      registers
      • now X=quotient=Y/X and Y=remainder=Y%X
      • allows easier recovery of original X using LastX *
  • MATH: add LN1+, E^X-
    • implement log(1+x) and e^x-1 respectively
    • more accurate than their naive implementations when x is close to 0
    • use mathematical identities involving hyperbolic sinh() and
      asinh() functions to avoid roundoff errors
  • TVM
    • add TVM (time value of money) submenu hierarchy (inspired by HP-12C
      and HP-30b)
    • implement relatively simple Newton-Secant root solver to calculate
      the I%YR from the other 4 TVM variables
    • significant performance and robustness improvements can probably be
      made in the future
  • add storage register arithmetic operations
    • STO+, STO-, STO*, STO/
    • RCL+, RCL-, RCL*, RCL/
  • convert to multi-page flash application
    • now consumes 2 flash pages (2 x 16 kiB)
  • CLEAR multiple times to clear RPN stack
    • If CLEAR is pressed on an empty edit line (just a _ cursor), then
      the message "CLEAR Again to Clear Stack" will be displayed.
    • If CLEAR is pressed again right after this message, the RPN stack is
      cleared, invoking the ROOT > CLR > CLST menu function.
    • Provides a quick shortcut to the CLST function which can be
      difficult to reach when the current menu item is deeply nested in
      another part of the menu hierarchy.
    • The TI-OS does not support 2ND CLEAR, it returns the same keycode as
      CLEAR. So invoking CLST on multiple CLEAR presses seemed like
      the most reasonable workaround.
  • implement jumpBack for MODE button shortcut
    • When ROOT > MODE is reached through the hierchical menu, the
      ON/EXIT/ESC button goes back up the menu hierarchy to the parent,
      the ROOT.
    • When ROOT > MODE is invoked through the MODE button on the
      keyboard, the ON/EXIT/ESC button jumps back to the previous menu
      location, instead of going back up the menu tree.
    • This allows quick changes to the FIX, SCI, and ENG display
      modes, without losing one's place in the menu hierarchy.
  • fix incorrect handling of DEL after a FIX, SCI, or ENG mode
    • when the DEL (backspace) button is pressed after a 2-digit argument
      of a FIX (or SCI etc), one of the digits of the 2-digit argument
      remained in the input buffer
    • the fix now correctly clears the input buffer when transitioning into
      edit mode from a normal mode
  • Potential Breaking Change: STO, RCL, FIX, SCI, ENG argument
    prompt is no longer saved and restored on QUIT or OFF
    • a new Command Arg parser was required to support storage register
      arithmetics
    • it uses a secondary GetKey() parsing loop which implements its own
      2ND QUIT and 2ND OFF handlers
    • the state of the secondary GetKey() parsing loop is not saved and
      restored

0.6.0 - save and restore app state; add carry flag; add BASE ops from HP-16C

• 0.6.0 (2023-09-22)
  • save application state
    • preserve app state into an appvar named RPN83SAV upon exit
    • reconstruct the app state upon restart
  • save X register to TI-OS ANS only on 2ND QUIT or 2ND OFF
    • previously saved to ANS every time X was changed
    • no user-visible change, but is more efficient internally
  • rename P>R to >REC, and R>P to >POL
    • for consistency with other conversion functions, and for consistency
      with HP-42S
    • I prefer the P>R and R>P but the difference is not worth breaking
      consistency
  • support custom MenuGroup handlers
    • absorb changeMenuGroup() functionality into the dispatchMenuNode()
    • add onExit events into changeMenuGroup()
    • add custom mBaseHandler for BASE menu to activate or deactivate
      the baseNumber upon entering or leaving the BASE menu hierarchy
  • BASE mode
    • make all BASE operations use u32 integers, even DEC mode
    • add Carry Flag which is updated for arithmetic, shifting, rotating
      operations
      • add SCF (set carry flag),CCF (clear carry flag), CF? (get
        carry flag)
      • add C or - display indicator
    • remove base number indicator (DEC, HEX, OCT, BIN) from the
      status line (top line)
      • no longer needed since those menu items show a "dot" when selected
      • the base number is only relevant within the BASE menu hierarchy
    • add ASL (arithmetic shift left), RLC (rotate left through carry
      flag), RRC (rotate right through carry flag)
    • add SLn, SRn, RLn, RRn, RLCn, RRCn (shift or rotate Y
      for X times)
    • add CB (clear bit), SB (set bit), B? (get bit)
    • add REVB (reverse bits), CNTB (count bits)
  • add additional HELP pages
    • CFIT Models
    • BASE Ops

0.5 - statistics and curve fit; menu selector dots

• 0.5.0 (2023-08-31)
  • USER_GUIDE.md, README.md
    • Update "Menu Indicator Arrows" section with latest screenshots which
      changed the menu arrows.
    • rename 'Menu Strip' to 'Menu Row' for consistency with HP-42S
      terminology.
  • BASE
    • display just a bare - for negatives numbers in BASE modes (instead
      of ... which is now reserved for valid numbers which overflows the
      number of digits supported by the display)
    • validate that the X and Y values are in the range of [0, 2^32)
      when performing bitwise operations (e.g. B+, AND, XOR, etc).
      Floating point numbers are truncated to u32 integers before the
      bitwise operations are performed.
  • Add menu selector dots
    • Replicate HP-42S menu selector dots, where a menu item can be both an
      action (e.g. select DEG) and a selection indicator.
    • display modes: FIX, SCI, ENG
    • trig modes: RAD, DEG
    • base modes: DEC, HEX, OCT, BIN
  • Improve menu name centering algorithm.
    • No change for strings which are even-number of pixels wide.
    • Strings which are odd-number of pixels wide are now centered
      perfectly, instead of being off-centered by one-px to the left.
    • Allows strings which are 17px wide to be rendered properly.
  • Add STAT menu items
    • 1 or 2 variable statistics
    • Sigma+ (add data point), Sigma- (remove data point)
    • SUM, MEAN, WMN (weighted mean)
    • SDEV (sample standard deviation), SCOV (sample covariance)
    • PDEV (population standard deviation), PCOV (population covariance)
  • Add CFIT curve fit menu items
    • Y>X (forcast X from Y)
    • X>Y (forcast Y from X)
    • SLOP (least square fit slope)
    • YINT (least square fit y-intercept)
    • CORR (correlation coefficient)
    • LINF (linear curve fit model)
    • LOGF (logarithmic curve fit model)
    • EXPF (exponential curve fit model)
    • PWRF (power curve fit model)
    • BEST (choose best curve fit model)
  • Fix RPN stack lift logic for pending input
    • Simplify stack lift logic to handle empty and non-empty pending input
      consistently.
    • If the input buffer is empty (showing just a _ cursor), then any
      subsequent keystroke that generates a single value (e.g. PI or
      STAT:N) replaces the empty X register.
    • If the input buffer is pending but not empty (i.e. has digits with a
      trailing _ cursor), then subsequent keystrokes causes a stack lift,
      preserving the pending input into the Y register.
    • If the subsequent keystroke is a function that consumes an X
      register, then the empty input buffer is assumed to be a 0 value.
  • Allow data transfer between RPN83P and TI-OS through the ANS variable.
    • When the RPN83P app starts, the TI-OS ANS variable (if Real) is
      available as the LastX register.
    • When the RPN83P app exits, the most recent X register becomes
      avaiable in TI-OS as the ANS variable.
  • Add X Root Y menu item under MATH

0.4 - more BASE function; improve speed of PRIM by 7x

• 0.4.0 (2023-08-16)
  • More BASE menu functions:
    • SL (shift left), SR (shift right), RL(rotate left circular), RR` (rotate right circular).
    • B+, B-, B*, B/
    • BDIV (division with remainder)
  • Map +, -, *, and / buttons to their bitwise counterparts when in
    HEX, OCT, or BIN modes.
    • Too confusing to have floating point operations bound to the
      easy-to-reach buttons while in HEX, OCT or BIN modes.
    • This is consistent with the HP-42S.
  • PRIM (isPrime)
    • change result values:
      • 1 if the number is a prime, or
      • smallest prime factor (always greater than 1) if not prime.
    • preserve the original X, and push it up to Y
      • allows the / button to be chained with additional PRIM to
        calculate all prime factors
      • see Prime Factors for details
    • improve speed by 7X using u32 integer routines instead of floating
      point routines

0.3.3 - use pandoc to convert markdown to PDF files

• 0.3.3 (2023-08-14)
  • Add Makefile targets for converting GitHub markdown files to PDF files.
  • Update some sections in README.md and USER_GUIDE.md.
  • No code change.

0.3.2 - add executive summary in README.md

• 0.3.2 (2023-08-13)
  • Add executive summary of the app at the top of README.md.
  • No code change.

0.3.1 - add animated GIFs of Examples 1 and 2

• 0.3.1 (2023-08-13)
  • Add animated GIF to illustrate Examples 1 and 2 in README.md.
  • No code change.

0.3 - rearrange some menu items for usability

• 0.3 (2023-08-13)
  • Move CLRG from F1 position to F3. Move CLX to F1. If the F1
    is accidentally hit twice when selecting the CLR menu group, then
    invoking CLX is a lot less destructive than invoking CLRG.
  • Move IP,FP,... menu strips before the ABS,SIGN,... menu strip. The
    IP,FP functions seem more frequently used than the ABS,SIGN functions.

Full Changelog: v0.2.1...v0.3