xcalc  scientific calculator for X
xcalc [stipple] [rpn] [
toolkitoption...]
xcalc is a scientific calculator desktop accessory that can emulate a
TI30 or an HP10C.
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 HP10C. Without this
flag, it will emulate a TI30.
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
n is the
corresponding digit, 0..9.
 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 reenter 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 viceversa. 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
"2.3E4" 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 0500, 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 TIspecific 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 HP10C. 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 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 
< 
ControlH 
clear() 
back() 
AC 

Clear 
clear() 

AC 
ON 
q 
quit() 
quit() 
AC 
ON 
ControlC 
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() 





+/ 
CHS 
n 
negate() 
negate() 






x:y 
x 

XexchangeY() 

ENTR 
Return 

enter() 

ENTR 
Linefeed 

enter() 
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: white
For each of buttons 20, 25, 30, 35, and 40, specify:
XCalc.ti.button20.background: black
XCalc.ti.button20.foreground: white
For 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
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
 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''.
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 appdefaults color
customization file:
/usr/local/share/X11/appdefaults/XCalccolor.
X(7), xrdb(1), the Athena Widget Set
HP mode is not completely debugged. In particular, the stack is not handled
properly after errors.
Copyright 1994 X Consortium
See
X(7) for a full statement of rights and permissions.
John Bradley, University of Pennsylvania
Mark Rosenstein, MIT Project Athena
Donna Converse, MIT X Consortium