gcalctool
gcalctool(1) gcalctool(1)
NAME
gcalctool - a desktop calculator
SYNOPSIS
gcalctool [ -D ] [ -E ] [ -a accuracy ] [ -v ] [ -? ]
DESCRIPTION
gcalctool is a desktop calculator. It has been designed to be used with
either the mouse or the keyboard. It is visually similar to a lot of
hand-held calculators. There are basic, financial and scientific modes.
Some of the calculator keys have menu marks. This indicates that there
is a menu associated with that key. Each key is discussed in more
detail below.
One of the most important things to remember about gcalctool is that
calculations are performed from left to right, with no arithmetic
precedence. If you need arithmetic precedence, then you should use
parentheses (see below).
Internal arithmetic is now done with multi-precision floating point
numbers. Accuracy can be adjusted from zero to nine numeric places in
fixed notation, but numbers can be displayed in engineering and scien-
tific notation as well. There is also an option to show or remove
trailing zeroes after the numeric point. The calculator reverts to
scientific notation when the number is larger than the display would
allow in fixed notation. In the scientific mode, the base of operation
can be changed between binary, octal, decimal and hexadecimal. Numbers
are initially displayed in fixed notation to nine numeric places, with
trailing zeroes removed, in the decimal base.
You can use the Copy and Paste functions in conjunction with the
numeric display to store or retrieve characters from the clipboard. You
can also remove the last digit entered, completely clear the displayed
entry and totally reset the calculator.
There are ten memory registers. Numbers can be stored or retrieved in
these locations, and arithmetic can be performed upon register con-
tents.
On startup, gcalctool will use several configuration resources stored
in a gconf database. These are listed in detail in the resources sec-
tion of these manual pages. Any constants or function definitions that
the user defines are also stored in this database.
Context sensitive help is also available. Control-F1 toggles whether
tooltip help is displayed for the item which currently has focus.
OPTIONS
-D Turning on gcalctool debugging.
-E Turning on debugging in the multiple precision arithmetic pack-
age.
-a accuracy
Initial number of digits displayed after the numeric point. This
value must be in the range 0 to 9. The default is nine numeric
places.
-v Show the version number and the usage message of this release of
the gcalctool program.
-? Show the version number and the usage message of this release of
the gcalctool program. Note that the ? character must be
escaped if using csh(1).
RESOURCES
On startup, gcalctool uses the following string type resources stored
in a gconf database:
Resource: /schemes/apps/gcalctool/accuracy
Values: Accuracy value
Description The number of of digits displayed after the numeric
point. This value must be in the range 0 to 9.
Resource: /schemes/apps/gcalctool/base
Values: Numeric Base
Description The initial numeric base. Valid values are "BIN"
(binary), "OCT" (octal), "DEC" (decimal) and "HEX" (hex-
adecimal).
Resource: /schemes/apps/gcalctool/display
Values: Display mode
Description The initial display mode. Valid values are "ENG" (engi-
neering), "FIX" (fixed-point) and "SCI" (scientific).
Resource: /schemes/apps/gcalctool/mode
Values: Mode
Description The initial calculator mode. Valid values are "BASIC",
"FINANCIAL" and "SCIENTIFIC".
Resource: /schemes/apps/gcalctool/showzeroes
Values: true, false (true)
Description Whether trailing zeroes, after the numeric point, are
shown in the display value.
Resource: /schemes/apps/gcalctool/showthousands
Values: true, false (false)
Description Whether fixed numbers in the decimal base are displayed
with thousands separated.
Resource: /schemes/apps/gcalctool/showregisters
Values: true, false (true)
Description Whether the memory register window is initially dis-
played.
Resource: /schemes/apps/gcalctool/trigtype
Values: Trig. type
Description The initial trigonometric type. Valid values are "DEG"
(degrees), "GRAD" (grads) and "RAD" (radians).
MENU BAR
This section describes the menu items available in the applications
menubar.
Calculator Menu
Quit [ Control-Q ]
Exit without user verification.
Edit Menu
Copy [ Control-C ]
Copy the calculators numeric display to the clip-
board.
Paste [ Control-V ]
Paste the contents of the clipboard into the calcula-
tors numeric display.
Insert ASCII Value [ Control-I ]
A separate window is displayed which allows you to
enter any character. The ASCII value of this charac-
ter is then displayed in the current base.
View Menu
Basic Mode [ Control-B ]
Display the calculator in basic mode.
Financial Mode [ Control-F ]
Display the calculator in financial mode.
Scientific Mode [ Control-S ]
Display the calculator in scientific mode.
Memory Registers [ Control-M ]
Display the memory registers window.
Help Menu
Contents... [ F1 ]
Display the online help for the calculator in a sepa-
rate window.
About Gcalctool [ Control-A ]
Display information about this application, including
the version number and the author.
CALCULATOR BUTTONS
This section describes the calculator keys present in the main
gcalctool window. gcalctool has three modes; basic, financial and sci-
entific. The keys associated with each of these modes are described in
separate sections below.
Keyboard equivalents appear in the square brackets. Note that Alt fol-
lowed by a letter indicates that the Alt key and this key should be
pressed together.
BASIC MODE
Numerical Keys [ 0-9 . = <Return> ].
Enter a digit (decimal digits 0-9) into the display. The '.' character
acts as the numeric point, and '=' (or Return) is used to complete
numerical entry.
Upto forty digits may be entered.
Arithmetical Operations [ + - x * / ].
Perform an arithmetical operation using the previous entry and the next
entry as operands. Addition, subtraction, multiplication and division
are denoted by the characters '+', '-', '*' and '/' respectively ('x'
is also synonymous with multiplication).
Number Manipulation Operators.
Int [ i ] Return the integer portion of the current entry.
Frac [ : ] Return the fractional portion of the current entry.
Abs [ u ] Return the absolute value of the current entry.
+/- [ c ] Change the arithmetic sign of the current entry.
1/x [ r ] Return the value of 1 divided by the current entry.
x^2 [ @ ] Return the square of the current entry.
% [ % ] Perform a percentage calculation using the last entry
and the next entry.
Sqrt [ s ] Perform a square root operation on the current entry.
Menu Operations.
Each of these operations has a popup menu associated with it. It is
also possible to use just the keyboard to achieve the same results.
The first keyboard value selects the menu operation; the second key-
board character selects the new value for this operation. Unlike the
menu facility available with the mouse, there is no visual feedback on
what choices are available to you, so the user has to know what item
they wish to select.
Acc [ a ] Set the display accuracy. Between 0 and 9 [ 0-9 ]
significant digits can be displayed.
Rcl [ R ] Retrieve memory register value. There are ten memory
registers [ 0-9 ].
Sto [ S ] Store value in memory register. There are ten memory
registers [ 0-9 ]. The register number may be pre-
ceded by an arithmetic operation (addition, subtrac-
tion, multiplication or division), in which case the
specified operation is carried out between the dis-
played entry and the value currently in the selected
memory register, and the result is placed in the mem-
ory register.
Exch [ X ] Exchange the current display with the contents of a
memory register. There are ten memory registers [ 0-9
].
Other Operations.
Clr [ Delete ] Clear the display, and reset the calculator.
CE [ Control-Back Space or Escape ]
Clear the display.
Bksp [ Back Space ]
Remove the rightmost character of the current entry,
and recalculate the displayed value.
FINANCIAL MODE
An example of how to use each of these financial calculations, is
available via the tooltip help facility.
Ctrm [ m ] Compounding term. Computes the number of compounding
periods it will take an investment of present value
pv to grow to a future value of fv, earning a fixed
interest rate int per compounding period.
Memory register usage:
Register 0 int (periodic interest rate).
Register 1 fv (future value).
Register 2 pv (present value).
Ddb [ d ] Double-declining depreciation. Computes the deprecia-
tion allowance on an asset for a specified period of
time, using the double-declining balance method.
Memory register usage:
Register 0 cost (amount paid for asset).
Register 1 salvage (value of asset at end of
life).
Register 2 life (useful life of the asset).
Register 3 period (time period for deprecia-
tion allowance).
Fv [ v ] Future value. This calculation determines the future
value of an investment. It computes the future value
based on a series of equal payments, each of amount
pmt, earning periodic interest rate int, over the
number of payment periods in term.
Memory register usage:
Register 0 pmt (periodic payment).
Register 1 int (periodic interest rate).
Register 2 n (number of periods).
Pmt [ P ] Periodic payment. Computes the amount of the periodic
payment of a loan. Most installment loans are com-
puted like ordinary annuities, in that payments are
made at the end of each payment period.
Memory register usage:
Register 0 prin (principal).
Register 1 int (periodic interest rate).
Register 2 n (term).
Pv [ p ] Present value. Determines the present value of an
investment. It computes the present value based on a
series of equal payments, each of amount pmt, dis-
counted at periodic interest rate int, over the num-
ber of periods in term.
Memory register usage:
Register 0 pmt (periodic payment).
Register 1 int (periodic interest rate).
Register 2 n (term).
Rate [ T ] Periodic interest rate. Returns the periodic interest
necessary for a present value of pv to grow to a
future value of fv over the number of compounding
periods in term.
Memory register usage:
Register 0 fv (future value).
Register 1 pv (present value).
Register 2 n (term).
Sln [ l ] Straight-line depreciation. Computes the straight-
line depreciation of an asset for one period. The
straight-line method of depreciation divides the
depreciable cost (cost - salvage) evenly over the
useful life of an asset. The useful life is the num-
ber of periods (typically years) over which an asset
is depreciated.
Memory register usage:
Register 0 cost (cost of the asset).
Register 1 salvage (salvage value of the
asset).
Register 2 life (useful life of the asset).
Syd [ Y ] Sum-of-the-years-digits depreciation. The sum-of-the-
years'-digits method of depreciation accelerates the
rate of depreciation, so that more depreciation
expense occurs in earlier periods than in later ones.
The depreciable cost is the actual cost minus salvage
value. The useful life is the number of periods (typ-
ically years) over which an asset is depreciated.
Memory register usage:
Register 0 cost (cost of the asset).
Register 1 salvage (salvage value of the
asset).
Register 2 life (useful life of the asset).
Register 3 period (period for which
depreciation is computed).
Term [ t ] Payment period. Returns the number of payment periods
in the term of an ordinary annuity necessary to accu-
mulate a future value of fv, earning a periodic
interest rate of int. Each payment is equal to amount
pmt.
Memory register usage:
Register 0 pmt (periodic payment).
Register 1 fv (future value).
Register 2 int (periodic interest rate).
SCIENTIFIC MODE
This section describes the functionality available in the calculators
scientific mode. This also includes a special mode panel used for set-
ting various options.
Mode Panel.
Numeric Base Set the numeric base of operation. Choices are
binary, octal, decimal (the default) and hexadecimal.
Display Type Set the display mode. Valid values are "Eng" (engi-
neering), "Fix" (fixed-point) and "Sci" (scientific).
Trigonometric Type
Set the trigonometric type. Valid values are Degrees,
Gradians and Radians.
Hyp Toggle the hyperbolic function indicator. This switch
affects the type of sine, cosine and tangent trigono-
metric functions performed.
Inv Toggle the inverse function indicator. This switch
affects the type of sine, cosine and tangent trigono-
metric functions performed.
Menu Operations.
Con [ # ] Retrieve and display a constant value. There are ten
constant values [ 0-9 ], and each one has a default
value which can be overridden when the user creates
their own constant definitions. The ten default val-
ues are:
0 0.621 kilometers per hour or miles per
hour
1 1.414213562 square root of 2
2 2.718281828 e
3 3.141592653 pi
4 0.3937007 centimeters or inches
5 57.295779513 degrees in a radian
6 1048576.0 2 to the power of 20
7 0.0353 grams or ounces
8 0.948 kilojoules or British thermals
9 0.0610 cubic centimeters or cubic inches
Fun [ f ] Retrieve and execute a function expression. There can
be upto ten functions expression defined by the user
[0 - 9]. There are no default function values.
Scientific buttons.
< [ < ] Shift the current entry to the left. The shift can be
between 1 and 15 places [ 1-9, A-F ]. This calculator
key has a popup menu associated with it.
> [ > ] Shift the current entry to the right. The shift can
be between 1 and 15 places [ 1-9, A-F ]. This calcu-
lator key has a popup menu associated with it.
&16 [ ] ] Truncate the current entry to a 16 bit unsigned inte-
ger.
&32 [ [ ] Truncate the current entry to a 32 bit unsigned inte-
ger.
( and ) [ ( and ) ]
Parentheses. Allow precedence with arithmetic calcu-
lations. Note that parentheses can be nested to any
level, and gcalctool provides a visual feedback of
what is being typed in, in the calculator display.
The calculation doesn't take place until the last
parenthesis is matched, then the display is updated
with the new result.
Exp [ e ] This is used to allow numbers to be entered in scien-
tific notation. The mantissa should be initially
entered, then the Exp key selected. The exponent is
then entered. If no numerical input had occurred when
the Exp key was selected, then a mantissa of 1.0 is
assumed.
e^x [ { ] Returns e raised to the power of the current entry.
10^x [ } ] Returns 10 raised to the power of the current entry.
y^x [ y ] Take the last entry and raise it to the power of the
next entry.
x! [ ! ] Return the factorial of the current entry. Note that
the factorial function is only valid for positive
integers.
Rand [ ? ] Return a random number between 0.0 and 1.0.
Hexadecimal Keys [ A-F ]
The hexadecimal numerical digits A-F. These buttons
will be insensitive unless the calculator is cur-
rently in the hexadecimal mode.
Cos [ J ] Return the trigonometric cosine, arc cosine, hyper-
bolic cosine or inverse hyperbolic cosine of the cur-
rent display, depending upon the current settings of
the hyperbolic and inverse function switches. The
result is displayed in the current trigonometric
units (degrees, radians or grads).
Sin [ K ] Return the trigonometric sine, arc sine, hyperbolic
sine or inverse hyperbolic sine of the current dis-
play, depending upon the current settings of the
hyperbolic and inverse function switches. The result
is displayed in the current trigonometric units
(degrees, radians or grads).
Tan [ L ] Return the trigonometric tangent, arc tangent, hyper-
bolic tangent or inverse hyperbolic tangent of the
current display, depending upon the current settings
of the hyperbolic and inverse function switches. The
result is displayed in the current trigonometric
units (degrees, radians or grads).
Ln [ N ] Return the natural logarithm of the current entry.
Log [ G ] Return the base 10 logarithm of the current entry.
Or [ | ] Perform a logical OR operation on the current entry
and the next entry,
And [ & ] Perform a logical AND operation on the current entry
and the next entry, treating both numbers as unsigned
long integers.
Not [ ~ ] Perform a logical NOT operation on the current entry.
Xor [ ^ ] Perform a logical XOR operation on the current entry
and the next entry, treating both numbers as unsigned
long integers.
Xnor [ n ] Perform a logical XNOR operation on the current entry
and the next entry, treating both numbers as unsigned
long integers.
FILES
~/.gcalctoolrc user's personal gcalctool resources for customizing
the appearance and color of gcalctool
7 February 2005 gcalctool(1)