*xcalc* accepts
all of the standard toolkit command line options along with two additional
options:

**-stipple**- This option indicates that the background of the calculator should be drawn using a stipple of the foreground and background colors. On monochrome displays improves the appearance.

**-rpn**- This option indicates that Reverse Polish Notation should be used. In this mode the calculator will look and behave like an HP-10C. Without this flag, it will emulate a TI-30.

*Pointer* Usage: Operations may be performed with pointer
button 1, or in some cases, with the keyboard. Many common calculator
operations have keyboard accelerators. To quit, press pointer button 3 on
the AC key of the TI calculator, or the ON key of the HP calculator.

*Calculator*
Key Usage (TI mode): The numbered keys, the +/- key, and the +, -, *, /,
and = keys all do exactly what you would expect them to. It should be
noted that the operators obey the standard rules of precedence. Thus, entering
"3+4*5=" results in "23", not "35". The parentheses can be used to override
this. For example, "(1+2+3)*(4+5+6)=" results in "6*15=90".

The entire number in the calculator display can be selected, in order to paste the result of a calculation into text.

The action procedures associated with
each function are given below. These are useful if you are interested in
defining a custom calculator. The action used for all digit keys is **digit( n**)
,
where

**1/x**- Replaces the number in the display
with its reciprocal. The corresponding action procedure is
**reciprocal()**. **x^2**- Squares the number in the display. The corresponding action procedure
is
**square()**. **SQRT**- Takes the square root of the number in the display. The
corresponding action procedure is
**squareRoot()**. **CE/C**- When pressed once,
clears the number in the display without clearing the state of the machine.
Allows you to re-enter a number if you make a mistake. Pressing it twice
clears the state, also. The corresponding action procedure for TI mode is
**clear()**. **AC**- Clears the display, the state, and the memory. Pressing it with
the third pointer button turns off the calculator, in that it exits the
program. The action procedure to clear the state is
**off()**; to quit,**quit()**. **INV**- Invert function. See the individual function keys for details. The corresponding
action procedure is
**inverse()**. **sin**- Computes the sine of the number in the
display, as interpreted by the current DRG mode (see DRG, below). If inverted,
it computes the arcsine. The corresponding action procedure is
**sine()**. **cos**- Computes the cosine, or arccosine when inverted. The corresponding action
procedure is
**cosine()**. **tan**- Computes the tangent, or arctangent when inverted.
The corresponding action procedure is
**tangent()**. **DRG**- Changes the DRG mode,
as indicated by 'DEG', 'RAD', or 'GRAD' at the bottom of of the calculator ``liquid
crystal'' display. When in 'DEG' mode, numbers in the display are taken as being
degrees. In 'RAD' mode, numbers are in radians, and in 'GRAD' mode, numbers
are in grads. When inverted, the DRG key has a feature of converting degrees
to radians to grads and vice-versa. Example: put the calculator into 'DEG'
mode, and enter "45 INV DRG". The display should now show something along
the lines of ".785398", which is 45 degrees converted to radians. The corresponding
action procedure is
**degree()**. **e**- The constant 'e'. (2.7182818...). The corresponding
action procedure is
**e()**. **EE**- Used for entering exponential numbers. For example,
to get "-2.3E-4" you'd enter "2 . 3 +/- EE 4 +/-". The corresponding action procedure
is
**scientific()**. **log**- Calculates the log (base 10) of the number in the display.
When inverted, it raises "10.0" to the number in the display. For example,
entering "3 INV log" should result in "1000". The corresponding action procedure
is
**logarithm()**. **ln**- Calculates the log (base e) of the number in the display.
When inverted, it raises "e" to the number in the display. For example,
entering "e ln" should result in "1". The corresponding action procedure
is
**naturalLog()**. **y^x**- Raises the number on the left to the power of the number
on the right. For example "2 y^x 3 =" results in "8", which is 2^3. For
a further example, "(1+2+3) y^x (1+2) =" equals "6 y^x 3" which equals "216".
The corresponding action procedure is
**power()**. **PI**- The constant 'pi'. (3.1415927....)
The corresponding action procedure is
**pi()**. **x!**- Computes the factorial of
the number in the display. The number in the display must be an integer
in the range 0-500, though, depending on your math library, it might overflow
long before that. The corresponding action procedure is
**factorial()**. **(**- Left
parenthesis. The corresponding action procedure for TI calculators is
**leftParen()**. **)**- Right parenthesis. The corresponding action procedure for TI calculators
is
**rightParen()**. **/**- Division. The corresponding action procedure is
**divide()**. *****- Multiplication. The corresponding action procedure is
**multiply()**. **-**- Subtraction.
The corresponding action procedure is
**subtract()**. **+**- Addition. The corresponding
action procedure is
**add()**. **=**- Perform calculation. The TI-specific action
procedure is
**equal()**. **STO**- Copies the number in the display to the memory
location. The corresponding action procedure is
**store()**. **RCL**- Copies the number
from the memory location to the display. The corresponding action procedure
is
**recall()**. **SUM**- Adds the number in the display to the number in the memory
location. The corresponding action procedure is
**sum()**. **EXC**- Swaps the number
in the display with the number in the memory location. The corresponding
action procedure for the TI calculator is
**exchange()**. **+/-**- Negate; change
sign. The corresponding action procedure is
**negate()**.**.**- Decimal point. The action procedure is
**decimal()**.*Calculator*Key Usage (RPN mode): The number keys, CHS (change sign), +, -, *, /, and ENTR keys all do exactly what you would expect them to do. Many of the remaining keys are the same as in TI mode. The differences are detailed below. The action procedure for the ENTR key is**enter()**.**<-**- This is a backspace key that can be used if you
make a mistake while entering a number. It will erase digits from the display.
(See BUGS). Inverse backspace will clear the X register. The corresponding
action procedure is
**back()**. **ON**- Clears the display, the state, and the memory.
Pressing it with the third pointer button turns off the calculator, in
that it exits the program. To clear state, the action procedure is
**off**; to quit,**quit()**. **INV**- Inverts the meaning of the function keys. This would
be the
*f*key on an HP calculator, but*xcalc*does not display multiple legends on each key. See the individual function keys for details. **10^x**- Raises
"10.0" to the number in the top of the stack. When inverted, it calculates
the log (base 10) of the number in the display. The corresponding action
procedure is
**tenpower()**. **e^x**- Raises "e" to the number in the top of the stack.
When inverted, it calculates the log (base e) of the number in the display.
The action procedure is
**epower()**. **STO**- Copies the number in the top of the stack to a memory location. There are 10 memory locations. The desired memory is specified by following this key with a digit key.
**RCL**- Pushes the number from the specified memory location onto the stack.
**SUM**- Adds the number on top of the stack to the number in the specified memory location.
**x:y**- Exchanges the numbers in the top two stack positions, the X and Y registers.
The corresponding action procedure is
**XexchangeY()**. **R v**- Rolls the stack
downward. When inverted, it rolls the stack upward. The corresponding action
procedure is
**roll()**. *blank*- These keys were used for programming functions
on the HP-10C. Their functionality has not been duplicated in
*xcalc*.

Finally, there are two additional action procedures:

**bell()**, which rings the bell; and**selection()**, which performs a cut on the entire number in the calculator's ``liquid crystal'' display.## Accelerators

Accelerators are shortcuts for entering commands.

*xcalc*provides some sample keyboard accelerators; also users can customize accelerators. The numeric keypad accelerators provided by*xcalc*should be intuitively correct. The accelerators defined by*xcalc*on the main keyboard are given below:

TI Key HP Key Keyboard Accelerator TI Function HP Function SQRT SQRT r squareRoot() squareRoot() AC ON space clear() clear() AC <- Delete clear() back() AC <- Backspace clear() back() AC <- Control-H clear() back() AC Clear clear() AC ON q quit() quit() AC ON Control-C quit() quit() INV i i inverse() inverse() sin s s sine() sine() cos c c cosine() cosine() tan t t tangent() tangent() DRG DRG d degree() degree() e e e() ln ln l naturalLog() naturalLog() y^x y^x ^ power() power() PI PI p pi() pi() x! x! ! factorial() factorial() ( ( leftParen() ) ) rightParen() / / / divide() divide() * * * multiply() multiply() - - - subtract() subtract() + + + add() add() = = equal() 0..9 0..9 0..9 digit() digit() . . . decimal() decimal() +/- CHS n negate() negate() x:y x XexchangeY() ENTR Return enter() ENTR Linefeed enter()

## Customization

The application class name is XCalc.*xcalc*has an enormous application defaults file which specifies the position, label, and function of each key on the calculator. It also gives translations to serve as keyboard accelerators. Because these resources are not specified in the source code, you can create a customized calculator by writing a private application defaults file, using the Athena Command and Form widget resources to specify the size and position of buttons, the label for each button, and the function of each button.The foreground and background colors of each calculator key can be individually specified. For the TI calculator, a classical color resource specification might be:

XCalc.ti.Command.background: gray50

XCalc.ti.Command.foreground: whiteFor each of buttons 20, 25, 30, 35, and 40, specify:

XCalc.ti.button20.background: black

XCalc.ti.button20.foreground: whiteFor each of buttons 22, 23, 24, 27, 28, 29, 32, 33, 34, 37, 38, and 39:

XCalc.ti.button22.background: white

XCalc.ti.button22.foreground: black## Widget Hierarchy

In order to specify resources, it is useful to know the hierarchy of the widgets which compose*xcalc*. In the notation below, indentation indicates hierarchical structure. The widget class name is given first, followed by the widget instance name.

XCalc xcalc Form ti

*or*hp*(the name depends on the mode)*Form bevel Form screen Label M Toggle LCD Label INV Label DEG Label RAD Label GRAD Label P Command button1 Command button2 Command button3*and so on, ...*Command button38 Command button39 Command button40## Application Resources

**rpn**(Class**Rpn**)- Specifies that the rpn mode should be used. The default is TI mode.
**stipple**(Class**Stipple**)- Indicates that the background should be stippled. The default is ``on'' for monochrome displays, and ``off'' for color displays.
**cursor**(Class**Cursor**)- The name of the symbol used to represent the pointer. The default is ``hand2''.

## Colors

If you would like xcalc to use its ti colors, include the following in the #ifdef COLOR section of the file you read with xrdb:*customization: -color

This will cause xcalc to pick up the colors in the app-defaults color customization file:*/usr/X11R6/lib/X11/app-defaults/XCalc-color*.## See Also

X(7) , xrdb(1) , the Athena Widget Set## Bugs

HP mode: A bug report claims that the sequence of keys 5, ENTER, <- should clear the display, but it doesn't.

## Copyright

Copyright 1994 X Consortium

See*X(7)*for a full statement of rights and permissions.## Authors

John Bradley, University of Pennsylvania

Mark Rosenstein, MIT Project Athena

Donna Converse, MIT X Consortium - Decimal point. The action procedure is