In general, you perform calculations by first entering data on to the stack, then executing functions that operate on the stack data. As an example, you can hit 1<enter>2<enter>+ in order to add 1 and 2.

A complex number is entered by first pressing '(', then entering the real part, then pressing ',' followed by the imaginary part. Alternatively, you can press '(' followed by the magnitude, then '<' followed by the phase angle. The angle will be interpreted in degrees or radians, depending on the current setting of the angle mode (see PERFORMING BASIC COMMAND OPERATIONS). Examples:

Keypresses	Resulting Entry
(1.23, 4.56<enter>	(1.23, 4.56)
(0.7072<45<enter>	(0.500065915655126, 0.50006591...
(1.23n,4.56<space>10<enter>	(-1.23, 45600000000)

would appear on the stack as [[1, 2][3, 4]].

Examples of matrix entry:

Keypresses	Resulting Entry
[1,2[3,4<enter>	[[1, 2][3, 4]]
[1.2<space>10,0[3n,5n<enter>	[[ 12000000000, 0 ][ -3, -5 ]]
[(1,2,3,4[5,6,7,8<enter>	[[ (1, 2), (3, 4) ][ (5, 6), (...

Examples of entering dimensioned data:

Keypresses	Resulting Entry
1.234_N*mm^2/s<enter>	1.234_N*mm^2*s^-1
(2.3,5_s^-4<enter>	(2.3, 5)_s^-4
[1,2[3,4_lbf*in<enter>	[[ 1, 2 ][ 3, 4 ]]_lbf*in
_nm<enter>	1_nm

Note that integer constants may have unlimited length, and the basic arithmetic operations (addition, subtraction, multiplication, division) will be performed using exact arithmetic when both arguments are integers.

Orpie also supports autocompletion of variable names. The help panel displays a list of pre-existing variables that partially match the name currently being entered. You can press '<tab>' to iterate through the list of matching variables.

As a shortcut, keys <f1>-<f12> will enter the variables (``registers'') @ r01 through @ r12.

Real and complex numbers and matrices may have units appended; just add a units string such as ``_N*m/s'' immediately following the numeric portion of the expression.

Notice that the complex matrix input parser is quite flexible; real and complex matrix elements may be mixed, and cartesian and polar complex formats may be mixed as well.

Multiple stack entries may be specified in the same file, if they are separated by whitespace. For example, entering (1, 2) 1.5 into the editor will cause the complex value (1, 2) to be placed on the stack, followed by the real value 1.5.

The input parser will discard whitespace where possible, so feel free to add any form of whitespace between matrix rows, matrix elements, real and complex components, etc.

As a shortcut, function operators will automatically enter any data that you were in the process of entering. So instead of the sequence 2<enter>2<enter>+, you could type simply 2<enter>2+ and the second number would be entered before the addition operation is applied.

As an additional shortcut, any variable names used as function arguments will be evaluated before application of the function. In other words, it is not necessary to evaluate variables before performing arithmetic operations on them.

To activate an abbreviation, press ''' (quote key), followed by the first few letters/digits of the abbreviation, then hit enter. Orpie offers an autocompletion feature for abbreviations, so you only need to type enough of the operation to identify it uniquely. The matching abbreviations will appear in the left panel of the display, to assist you in finding the appropriate operation.

To avoid interface conflicts, abbreviations may be entered only when the entry buffer (the bottom line of the screen) is empty.

The following functions are available as abbreviations:

Abbreviations	Functions
inv	inverse function
pow	raise element 2 to the power of element 1
sq	square last element
sqrt	square root function
abs	absolute value function
exp	exponential function
ln	natural logarithm function
10^	base 10 exponential function
log10	base 10 logarithm function
conj	complex conjugate function
sin	sine function
cos	cosine function
tan	tangent function
sinh	hyperbolic sine function
cosh	hyperbolic cosine function
tanh	hyperbolic tangent function
asin	arcsine function
acos	arccosine function
atan	arctangent function
asinh	inverse hyperbolic sine function
acosh	inverse hyperbolic cosine function
atanh	inverse hyperbolic tangent function
re	real part of complex number
im	imaginary part of complex number
gamma	Euler gamma function
lngamma	natural log of Euler gamma function
erf	error function
erfc	complementary error function
fact	factorial function
gcd	greatest common divisor function
lcm	least common multiple function
binom	binomial coefficient function
perm	permutation function
trans	matrix transpose
trace	trace of a matrix
solvelin	solve a linear system of the form Ax = b
mod	element 2 mod element 1
floor	floor function
ceil	ceiling function
toint	convert a real number to an integer type
toreal	convert an integer type to a real number
add	add last two elements
sub	subtract element 1 from element 2
mult	multiply last two elements
div	divide element 2 by element 1
neg	negate last element
store	store element 2 in (variable) element 1
eval	evaluate variable to obtain contents
purge	delete a variable
total	sum the columns of a real matrix
mean	compute the sample means of the columns of a real matrix
sumsq	sum the squares of the columns of a real matrix
var	compute the unbiased sample variances of the columns of a real matrix
varbias	compute the biased (population) sample variances of the columns of a real matrix
stdev	compute the unbiased sample standard deviations of the columns of a real matrix
stdevbias	compute the biased (pop.) sample standard deviations of the columns of a matrix
min	find the minima of the columns of a real matrix
max	find the maxima of the columns of a real matrix
utpn	compute the upper tail probability of a normal distribution
uconvert	convert element 2 to an equivalent expression with units matching element 1
ustand	convert to equivalent expression using SI standard base units
uvalue	drop the units of the last element

Entering abbreviations can become tedious when performing repetitive calculations. To save some keystrokes, Orpie will automatically bind recently-used operations with no prexisting binding to keys <f5>-<f12>. The current autobindings can be viewed by pressing 'h' to cycle between the various pages of the help panel.

The left and right scrolling option may prove useful for viewing very lengthy stack entries, such as large matrices. The edit option provides a convenient way to correct data after it has been entered on the stack.

Orpie supports the standard SI prefix set, {y, z, a, f, p, n, u, m, c, d, da, h, k, M, G, T, P, E, Z, Y} (note the use of 'u' for micro-). These prefixes may be applied to any of the following exhaustive sets of units:

String	Length Unit
m	meter
ft	foot
in	inch
yd	yard
mi	mile
pc	parsec
AU	astronomical unit
Ang	angstrom
furlong	furlong
pt	PostScript point
pica	PostScript pica
nmi	nautical mile
lyr	lightyear

String	Mass Unit
g	gram
lb	pound mass
oz	ounce
slug	slug
lbt	Troy pound
ton	(USA) short ton
tonl	(UK) long ton
tonm	metric ton
ct	carat
gr	grain

String	Time Unit
s	second
min	minute
hr	hour
day	day
yr	year
Hz	Hertz

String	Temperature Unit
K	Kelvin
R	Rankine

Note: No, Celsius and Fahrenheit will not be supported. Because these temperature units do not share a common zero point, their behavior is ill-defined under many operations.

String	Force Unit
N	Newton
lbf	pound force
dyn	dyne
kip	kip

String	Energy Unit
J	Joule
erg	erg
cal	calorie
BTU	british thermal unit
eV	electron volt

String	Electrical Unit
A	Ampere
C	Coulomb
V	volt
Ohm	Ohm
F	Farad
H	Henry
T	Tesla
G	Gauss
Wb	Weber
Mx	Maxwell

String	Power Unit
W	Watt
hp	horsepower

String	Pressure Unit
Pa	Pascal
atm	atmosphere
bar	bar
Ohm	Ohm
mmHg	millimeters of mercury
inHg	inches of mercury

Orpie is Free Software; it has been made available under version 2 of the GNU General Public License (GPL). You should have received a copy of the GPL along with this program, in the file ``COPYING''.

Orpie includes portions of the ocamlgsl [1] bindings supplied by Olivier Andrieu, as well as the curses bindings from the OCaml Text Mode Kit [2] written by Nicolas George. I would like to thank these authors for helping to make Orpie possible.

Orpie author: Paul Pelzl <pelzlpj@eecs.umich.edu> Orpie website:

Feel free to contact me if you have bugs, feature requests, patches, etc. I would also welcome volunteers interested in packaging Orpie for various platforms.

Orpie is developed with the aid of the excellent GNU Arch RCS [3]. Interested developers are advised to track Orpie development via my public archive: pelzlpj@eecs.umich.edu--2004 http://www-personal.engin.umich.edu/~pelzlpj/tla/2004 Orpie uses tla's ``configs'' support. After getting a copy of the source, run "tla build-config dist.arch" in the project tree root to grab the extra packages that Orpie depends on.

At the moment, I would really appreciate help writing additional test cases for the calculator object. It's not terribly difficult, just time-consuming. If you're interested in lending a hand, have a look at the source in calc_test.ml and use "make test.opt" to build the testing executable.

Do you feel compelled to compensate me for writing Orpie? As a poor, starving graduate student, I will gratefully accept donations. Please see for more information.

(5), orpie-curses-keys(1)