# Manuale di gcalctool

gcalctool è una calcolatrice per GNOME. Include modalità base, avanzata, finanziaria e scientifica e fa uso nei suoi calcoli di un pacchetto a precisione multipla in modo da fornire un alto grado di accuratezza.

2003
2004
2005
Sun Microsystems
Progetto di documentazione di GNOME

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License (GFDL), Version 1.1 or any later version published by the Free Software Foundation with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. You can find a copy of the GFDL at this link or in the file COPYING-DOCS distributed with this manual.

This manual is part of a collection of GNOME manuals distributed under the GFDL. If you want to distribute this manual separately from the collection, you can do so by adding a copy of the license to the manual, as described in section 6 of the license.

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DOCUMENT AND MODIFIED VERSIONS OF THE DOCUMENT ARE PROVIDED UNDER THE TERMS OF THE GNU FREE DOCUMENTATION LICENSE WITH THE FURTHER UNDERSTANDING THAT:

1. DOCUMENT IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, WITHOUT LIMITATION, WARRANTIES THAT THE DOCUMENT OR MODIFIED VERSION OF THE DOCUMENT IS FREE OF DEFECTS MERCHANTABLE, FIT FOR A PARTICULAR PURPOSE OR NON-INFRINGING. THE ENTIRE RISK AS TO THE QUALITY, ACCURACY, AND PERFORMANCE OF THE DOCUMENT OR MODIFIED VERSION OF THE DOCUMENT IS WITH YOU. SHOULD ANY DOCUMENT OR MODIFIED VERSION PROVE DEFECTIVE IN ANY RESPECT, YOU (NOT THE INITIAL WRITER, AUTHOR OR ANY CONTRIBUTOR) ASSUME THE COST OF ANY NECESSARY SERVICING, REPAIR OR CORRECTION. THIS DISCLAIMER OF WARRANTY CONSTITUTES AN ESSENTIAL PART OF THIS LICENSE. NO USE OF ANY DOCUMENT OR MODIFIED VERSION OF THE DOCUMENT IS AUTHORIZED HEREUNDER EXCEPT UNDER THIS DISCLAIMER; AND

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Sun Microsystems Inc.
Manuale di Calcolatrive V2.9
Marzo 2005

Sun Java Desktop System Documentation Team

Progetto di documentazione di GNOME

Manuale di Calcolatrive V2.8
Agosto 2004

Sun Java Desktop System Documentation Team

Progetto di documentazione di GNOME

Manuale di gcalctool V2.7
Febbraio 2004

Sun GNOME Documentation Team

Progetto di documentazione di GNOME

Manuale di gcalctool V2.6
Ottobre 2003

Sun GNOME Documentation Team

Progetto di documentazione di GNOME

Manuale di gcalctool V2.5
Luglio 2003

Sun GNOME Documentation Team

Progetto di documentazione di GNOME

Manuale di gcalctool V2.4
Giugno 2003

Sun GNOME Documentation Team

Progetto di documentazione di GNOME

Manuale di gcalctool V2.3
Aprile 2003

Sun GNOME Documentation Team

Progetto di documentazione di GNOME

Manuale di gcalctool V2.2
Aprile 2003

Sun GNOME Documentation Team

Progetto di documentazione di GNOME

Manuale di gcalctool V2.1
Marzo 2003

Sun GNOME Documentation Team

Progetto di documentazione di GNOME

Manuale di gcalctool V2.0
Marzo 2003

Sun GNOME Documentation Team

Progetto di documentazione di GNOME

Questo manuale descrive la versione 5.5.37 di Calcolatrice.

## Commenti

Per segnalare un problema o inviare suggerimenti sull'applicazione gcalctool o su questo manuale, seguire le istruzioni presenti alla Pagina di commenti su GNOME.

## Introduzione

L'applicazione gcalctool dispone delle seguenti modalità per gestire diversi tipi di approcci matematici:

Base

  La modalità predefinita. Fornisce le funzioni standard della calcolatrice. Nella modalità Base è possibile eseguire le tipiche funzioni di addizione, sottrazione, divisione e moltiplicazione; tutte le funzioni di questa modalità possono essere usate in ciascuna delle altre modalità.

Avanzata

  Fornisce funzioni di calcolo avanzate. È possibile memorizzare numeri in dieci diversi registri di memoria e di richiamare e sostituire in modo semplice i numeri contenuti in questi registri. È possibile usare tutte le funzioni presenti in questa modalità nelle modalità Finanziaria e Scientifica.

Finanziaria

  Fornisce diverse funzioni finanziarie complesse.

Scientifica

  Fornisce molte funzioni matematiche aggiuntive, incluse le funzioni trigonometriche e logiche. Nella modalità Scientifica è anche possibile memorizzare funzioni e costanti personalizzate.

È possibile usare gcalctool nei seguenti sistemi numerici:

Sistema numerico | Base
--- | ---
Binario | 2
Ottale | 8
Decimale | 10
Esadecimale | 16

## Per cominciare

È possibile avviare gcalctool nei seguenti modi:

Menù

  Scegliere Accessori Calcolatrice.

Riga di comando

  Eseguire il seguente comando: `gnome-calculator`

All'avvio di gcalctool viene visualizzata la finestra seguente.

### Finestra della modalità base di gcalctool

Mostra la finestra della modalità base di gcalctool

The gcalctool window contains the following elements:

Menubar

  The menus on the menubar contain all of the commands that you need to work with gcalctool.

Display area

  The display area shows the numbers that you enter, and the results of calculations. If you are not using arithmetic precedence, you can only enter numbers of up to forty digits.

Mode area

  The mode area displays the buttons for the current mode. The Basic mode buttons are always displayed. Advanced mode buttons are also available in Financial and Scientific modes.

Popup Menu

  The Shows popup-menu symbol. symbol on a gcalctool button indicates that a popup menu is displayed when you click on that button.

Status Bar

  The status bar displays messages on the status of your calculations.

## Usage

### To Use Calculator Functions

To perform a calculation, use one of the following methods:

- Click on the gcalctool buttons to enter numbers and functions.

- Give focus to the gcalctool window, then use the keyboard or numeric keypad to specify the calculation that you want to perform. For a complete list of keyboard shortcuts, see .

The gcalctool application automatically displays numbers with more than 40 digits, and small numbers, as exponential numbers. For example, the following table shows the value that is displayed when you use the decimal numeric base with an accuracy of 2 significant places:

Display | Signifies
--- | ---
1.23e+37 | 1.23 * 1037
1e-5 | 0.00001

For information about how to enter a number in exponential format, see .

#### To Display a Separator in Large Numbers

To insert a separator between every three digits to the left of the numeric point in decimal base, choose View Show Thousands Separator.

Different countries and cultures have varying conventions for how to communicate. These conventions include the language spoken and the character used as a numeric separator.

gcalctool has been internationalized so user's can adapt to their own conventions. This is done by setting a specific locale. We can't determine what locales will exist, except for a standard one called the C locale.

When you use the C locale, the separator character is not displayed.

#### To Copy and Paste in the Display Area

To copy the result of a calculation, choose Edit Copy. You can paste the value into another application.

To paste a previously copied value into the display area, choose Edit Paste.

### To Perform Basic Calculations

Basic mode is displayed by default when you first start gcalctool. To explicitly invoke Basic mode, choose View Basic.

The calculator memory registers are unavailable in Basic Mode. In other words, View Memory Registers is inactive.

#### To Perform Simple Calculations

To perform simple calculations, use the buttons described in .

##### Performing Simple Calculations

Function | Button | Description | Example | Result
--- | --- | --- | --- | ---
Numerals | 0 to 9 inclusive | In decimal and hexadecimal base, all numerals are available. In octal base, 8 and 9 are unavailable. In binary base, only 0 and 1 are available. The default base is decimal. | 1 | 1
Numeric point | . | Starts the fractional part of a numeric entry. | 1 . 2 | 1.2
Calculate a result | = | Displays the result of the current calculation in the current base. | 1 + 2 = | 3
Addition | + | Adds the current value in the display area to the next number that you enter. | 1 + 2 = | 3
Subtraction | - | Subtracts from the current value in the display area the next number that you enter. | 3 - 2 = | 1
Multiplication | * | Multiplies the current value in the display area by the next number that you enter. | 3 * 2 = | 6
Division | / | Divides the current value in the display area by the next number that you enter. | 6 / 3 = | 2
Change the arithmetic sign | +/- | Changes a positive number to a negative number, or a negative number to a positive number. | 8 +/- | -8

#### To Erase Characters

To erase characters, use the buttons described in .

##### Erasing Characters

Function | Button | Description | Example | Result
--- | --- | --- | --- | ---
Backspace | Bksp | Removes the rightmost character from the display area. | 1 + 2 2 Bksp = | 3

Clear Entry

CE

Removes the current value from the display area.

This is only really meaningful if the Calculator is not in Arithmetic Precedence mode.

In Arithmetic Precedence mode, this operation is the same as Clr

If the calculator is not in Arithmetic Precedence mode:

1 + 2 2 CE =

If the calculator is in Arithmetic Precedence mode:

1 + 2 2 CE =

If the calculator is not in Arithmetic Precedence mode:

1

If the calculator is in Arithmetic Precedence mode:

0

Clear | Clr | Resets the current value in the display area to zero and removes any previous calculation results. Clr also deselects the Hyp and Inv options in Scientific. | 1 + 2 2 Clr | 0

#### To Display ASCII Values

To display the ASCII value of a character, choose Edit Insert ASCII Value .

The Insert ASCII Value dialog is displayed.

Enter the required character in the Character field, then click Insert. The ASCII value of that character, in the current numeric base, appears in the display area. For example, the ASCII value of B in decimal base is 66.

### To Perform Advanced Calculations

To change to Advanced mode, choose View Advanced .

When you change to Advanced mode, the following buttons are displayed to the right of the Basic mode buttons:

#### gcalctool Advanced Mode Buttons

Shows gcalctool Advanced mode buttons.

#### Performing Advanced Calculations

Function | Button | Description | Example | Result
--- | --- | --- | --- | ---
Percentage | % | Divides the current value by 100. | 560 % = | 5.60
Reciprocal | 1/x | Divides 1 by the current value in the display area. | 4 1/x | 0.25
Square Root | Sqrt | Calculates the square root of the current value in the display area. | For arithmetic precedence mode: Sqrt 9 )= For non-arithmetic precedence mode: 9 Sqrt | 3
Square | x2 | Calculates the square of the current value in the display area. | 3 x2 | 9
Integer Portion | Int | Calculates the integer portion of the current value in the display area. | -23.45 Int | -23
Fractional Portion | Frac | Calculates the fractional portion of the current value in the display area. | -23.45 Frac | -0.45
Absolute Value | Abs | Calculates the absolute value of the current value in the display area. | -23.45 Abs | 23.45
Parentheses | ( and ) | Provide precedence in arithmetic calculations if you are not using Arithmetic Precedence. See also . Calculations within parentheses are performed first. You can nest parentheses to any level. When the last parenthesis is matched, the display area is updated. | 2 + 3 * 4 = 2 + ( 3 * 4 ) | 20 14

#### To Use the Calculator Memory Registers

You can store values in any of the ten gcalctool memory registers R0 to R9. To display the memory registers, choose View Memory Registers .

The memory registers can be dismissed by either choosing View Memory Registers again, or by clicking on the Close button in the memory register window.

describes the memory functions that you can use.

##### Memory Functions

Function | Button | Description | Example | Result
--- | --- | --- | --- | ---

Store Value in Memory Register

Sto

Stores the current contents of the display area in the specified memory register. Click Sto, then select a memory register from the popup menu.

To clear a memory register during a gcalctool session:

1. Click Clr.

2. Click Sto.

3. Select the memory register from the popup menu.

22 Sto R2

The value 22 is stored in memory register R2.

Retrieve Value From Memory Register | Rcl | Retrieves the contents of the specified memory register. Click Rcl, then select the memory register from the popup menu. | 0 Rcl R2 | The value in the display area is 22.
Exchange Memory Register Value and Displayed Value | Exch | Exchanges the contents of the specified memory register and the current value in the display area. Click Exch, then select the memory register from the popup menu. | 44 Exch R2 | The value in the display area changes from 44 to 22, the value in R2 changes from 22 to 44.

If you use keyboard shortcuts, you can use the keyboard to specify the memory register, as shown in the following examples:

Keyboard Entry | Description
--- | ---
S 2 | Stores the current contents of the display area in memory register R2.
R 2 | Retrieves the current contents of memory register R2 into the display area.
X 2 | Exchanges the current value of the display area with the contents of memory register R2.

### To Perform Financial Calculations

To change to Financial mode, choose View Financial .

When you change to Financial mode, the following buttons are displayed above the Basic and Advanced mode buttons:

#### gcalctool Financial Mode Buttons

Shows gcalctool Financial mode buttons.

To perform financial calculations, use the buttons described in .

#### Performing Financial Calculations

Function | Button | Description | Example | Result
--- | --- | --- | --- | ---

Compounding Term

Ctrm

Calculates the number of compounding periods necessary to increase an investment of present value pv to a future value of fv, at a fixed interest rate of int per compounding period.

This function uses the following memory registers:

Register 0

  int, the periodic interest rate

Register 1

  fv, the future value

Register 2

  pv, the present value

You have just deposited $8000 in an account that pays an annual interest rate of 9%, compounded monthly. Given the annual interest rate, you determine that the simple monthly interest rate is 0.09 / 12 = 0.0075. To calculate the time period necessary to double your investment, put the following values into the first three memory registers:

Register 0

  0.0075

Register 1

  16000

Register 2

  8000

Click Ctrm =

92.77

The investment doubles in value in 92.77 months.

Double-Declining Depreciation

Ddb

Calculates the depreciation allowance on an asset for a specified period of time, using the double-declining balance method.

This function uses the following memory registers:

Register 0

  cost, the amount paid for the asset

Register 1

  salvage, the value of the asset at the end of its life

Register 2

  life, the useful life of the asset

Register 3

  period, the time period for depreciation allowance

You have just purchased an office machine for $8000. The useful life of this machine is six years. The salvage value after six years is $900. To calculate the depreciation expense for the fourth year, using the double-declining balance method, put the following values into the first four memory registers:

Register 0

  8000

Register 1

  900

Register 2

  6

Register 3

  4

Click Ddb =

790.12

The depreciation expense for the fourth year is $790.12.

Future Value

Fv

Calculates the future value of an investment based on a series of equal payments, each of amount pmt, at a periodic interest rate of int, over the number of payment periods in the term.

This function uses the following memory registers:

Register 0

  pmt, the periodic payment

Register 1

  int, the periodic interest rate

Register 2

  n, the number of periods

You plan to deposit $4000 in a bank account on the last day of each year for the next 20 years. The account pays 8% interest, compounded annually. Interest is paid on the last day of each year. To calculate the value of your account in 20 years, put the following values into the first three memory registers:

Register 0

  4000

Register 1

  0.08

Register 2

  20

Click Fv =

183047.86

At the end of 20 years, the value of the account is $183,047.86.

Periodic Payment

Pmt

Calculates the amount of the periodic payment of a loan, where payments are made at the end of each payment period.

This function uses the following memory registers:

Register 0

  prin, the principal

Register 1

  int, the periodic interest rate

Register 2

  n, the term

You are considering a $120,000 mortgage for 30 years at an annual interest rate of 11.0%. Given the annual interest rate, you determine that the simple monthly interest rate is 0.11 / 12 = 0.00917. The term is 30 * 12 = 360 months. To calculate the monthly repayment for this mortgage, put the following values into the first three memory registers:

Register 0

  120000

Register 1

  0.00917

Register 2

  360

Click Pmt =

1143.15

The monthly repayment is $1143.15.

Present Value

Pv

Calculates the present value of an investment based on a series of equal payments, each of amount pmt, discounted at a periodic interest rate of int, over the number of payment periods in the term.

This function uses the following memory registers:

Register 0

  pmt, the periodic payment

Register 1

  int, the periodic interest rate

Register 2

  n, the number of periods

You have just won a million dollars. The prize is awarded in 20 annual payments of $50,000 each. Annual payments are received at the end of each year. If you were to accept the annual payments of $50,000, you would invest the money at a rate of 9%, compounded annually.

However, you are given the option of receiving a single lump-sum payment of $400,000 instead of the million dollars annuity. To calculate which option is worth more in today's dollars, put the following values into the first three memory registers:

Register 0

  50000

Register 1

  0.09

Register 2

  20

Click Pv =

456427.28

The $1,000,000 paid over 20 years is worth $456,427.28 in present dollars.

Periodic Interest Rate

Rate

Calculates the periodic interest necessary to increase an investment of present value pv to a future value of fv, over the number of compounding periods in term.

This function uses the following memory registers:

Register 0

  fv, the future value

Register 1

  pv, the present value

Register 2

  n, the term

You have invested $20,000 in a bond. The bond matures in five years, and has a maturity value of $30,000. Interest is compounded monthly. The term is 5 * 12 = 60 months. To calculate the periodic interest rate for this investment, put the following values into the first three memory registers:

Register 0

  30000

Register 1

  20000

Register 2

  60

Click Rate =

.00678

The monthly interest rate is 0.678%. The annual interest rate is 0.678% * 12 = 8.14%.

Straight-Line Depreciation

Sln

Calculates the straight-line depreciation of an asset for one period. The depreciable cost is cost - salvage. The straight-line method of depreciation divides the depreciable cost evenly over the useful life of an asset. The useful life is the number of periods, typically years, over which an asset is depreciated.

This function uses the following memory registers:

Register 0

  cost, the amount paid for the asset

Register 1

  salvage, the value of the asset at the end of its life

Register 2

  life, the useful life of the asset

You have just purchased an office machine for $8000. The useful life of this machine is six years. The salvage value after six years is $900. To calculate the yearly depreciation expense, using the straight-line method, put the following values into the first three memory registers:

Register 0

  8000

Register 1

  900

Register 2

  6

Click Sln =

1183.33

The yearly depreciation expense is $1183.33.

Sum-Of-The-Years'-Digits Depreciation

Syd

Calculates the depreciation allowance on an asset for a specified period of time, using the Sum-Of-The-Years'-Digits method. This 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 cost - salvage. The useful life is the number of periods, typically years, over which an asset is depreciated.

This function uses the following memory registers:

Register 0

  cost, the amount paid for the asset

Register 1

  salvage, the value of the asset at the end of its life

Register 2

  life, the useful life of the asset

Register 3

  period, the time period for depreciation allowance

You have just purchased an office machine for $8000. The useful life of this machine is six years. The salvage value after six years is $900. To calculate the depreciation expense for the fourth year, using the sum-of-the-years'-digits method, put the following values into the first four memory registers:

Register 0

  8000

Register 1

  900

Register 2

  6

Register 3

  4

Click Syd =

1014.29

The depreciation expense for the fourth year is $1014.29.

Payment Period

Term

Calculates the number of payment periods that are necessary during the term of an ordinary annuity, to accumulate a future value of fv, at a periodic interest rate of int. Each payment is equal to amount pmt.

This function uses the following memory registers:

Register 0

  pmt, the periodic payment

Register 1

  fv, the future value

Register 2

  int, the periodic interest rate

You plan to deposit $1800 in a bank account on the last day of each year. The account pays 11% interest, compounded annually. Interest is paid on the last day of each year. To calculate the time period necessary to accumulate $120,000, put the following values into the first three memory registers:

Register 0

  1800

Register 1

  120000

Register 2

  0.11

Click Term =

20.32

$120,000 accumulates in the account in 20.32 years.

### To Perform Scientific Calculations

To change to Scientific mode, choose View Scientific .

When you change to Scientific mode, the following buttons are displayed above the Basic and Advanced mode buttons:

#### gcalctool Scientific Mode Buttons

Shows gcalctool Scientific mode buttons.

#### To Set the Accuracy

To set the accuracy of the display area and of the memory registers, click Acc, then select from the popup menu the accuracy level that you require. The current accuracy level is indicated by a preceding black circle in the popup menu. Up to 99 significant places can be displayed. The default accuracy is 9 significant places.

To set the accuracy level above 9, select Other (9) ..., then choose the accuracy level you require in the Set Precision popup.

By default, trailing zeroes are not shown. To display trailing zeroes, click Acc then select Show Trailing Zeroes from the popup menu, or choose View Show Trailing Zeroes . A preceding check mark in the Acc popup menu or View menu indicates that the Show Trailing Zeroes option has been selected. To hide trailing zeroes, choose View Show Trailing Zeroes again.

The examples in the following table show how the accuracy setting affects x in the display area, when you use decimal base, with the Show Trailing Zeroes option selected, for the `1 / 8 = x` calculation:

Accuracy | Result
--- | ---
1 significant place | 1.2
2 significant places | 1.25
3 significant places | 1.250

#### To Set the Numeric Base

To set the numeric base, select one of the buttons described in .

##### Setting the Numeric Base

Function | Button | Description
--- | --- | ---
Binary Base | Bin | Sets the numeric base to binary, that is, base 2.
Octal Base | Oct | Sets the numeric base to octal, that is, base 8.
Decimal Base | Dec | Sets the numeric base to decimal, that is, base 10. Decimal is the default numeric base. If you change from Scientific mode to another mode, gcalctool automatically sets the numeric base to decimal.
Hexadecimal Base | Hex | Sets the numeric base to hexadecimal, that is, base 16.

#### To Set the Display Type

To set the display type, select one of the buttons described in .

##### Setting the Display Type

Function | Button | Description
--- | --- | ---
Engineering Display Type | Eng | Sets the display type to engineering format. Results are displayed in scientific notation. The exponent is always a multiple of three.
Fixed-Point Display Type | Fix | Sets the display type to fixed-point format. Results are not displayed in scientific notation. Fixed-point is the default display type. If you change from scientific mode to either basic mode or financial mode, gcalctool automatically sets the display type to fixed-point format.
Scientific Display Type | Sci | Sets the display type to scientific format. Results are displayed in scientific notation, with a fixed number of numeric digits.

#### To Set the Trigonometric Type

To set the trigonometric type, select one of the buttons described in .

##### Setting the Trigonometric Type

Function | Button | Description
--- | --- | ---
Degrees | Degrees | Sets the trigonometric type to degrees. Degrees is the default trigonometric type.
Gradians | Gradians | Sets the trigonometric type to gradians.
Radians | Radians | Sets the trigonometric type to radians.

#### To Set the Trigonometric Options

To set the trigonometric options, use the options described in .

##### Setting the Trigonometric Options

Function | Button | Description
--- | --- | ---
Hyperbolic Option Indicator | Hyp | Selects the hyperbolic option for use with the trigonometric functions.
Inverse Option Indicator | Inv | Selects the inverse option for use with the trigonometric functions.

By default, the options described in are not selected. Click Clr to deselect these options.

#### To Calculate Trigonometric Values

To calculate trigonometric values, use the buttons described in .

##### Calculating Trigonometric Values

Function | Button | Description | Example | Result
--- | --- | --- | --- | ---
Cosine `cos` | Cos, Hyp option not selected, Inv option not selected | Calculates the cosine of the current value in the display area. | 60 Cos | 0.5
Arc Cosine `acos` | Cos, Hyp option not selected, Inv option selected | Calculates the arc cosine of the current value in the display area. | 0.5 Inv Cos | 60
Hyperbolic Cosine `cosh` | Cos, Hyp option selected, Inv option not selected | Calculates the hyperbolic cosine of the current value in the display area. | 0.4 Hyp Cos | 1.081072372
Arc Hyperbolic Cosine `acosh` | Cos, Hyp option selected, Inv option selected | Calculates the arc hyperbolic cosine of the current value in the display area. | 1.6 Hyp Inv Cos | 1.046967915
Sine `sin` | Sin, Hyp option not selected, Inv option not selected | Calculates the sine of the current value in the display area. | 90 Sin | 1
Arc Sine `asin` | Sin, Hyp option not selected, Inv option selected | Calculates the arc sine of the current value in the display area. | 1 Inv Sin | 90
Hyperbolic Sine `sinh` | Sin, Hyp option selected, Inv option not selected | Calculates the hyperbolic sine of the current value in the display area. | 0.4 Hyp Sin | 0.410752326
Arc Hyperbolic Sine `asinh` | Sin, Hyp option selected, Inv option selected | Calculates the arc hyperbolic sine of the current value in the display area. | 1.6 Hyp Inv Sin | 1.248983328
Tangent `tan` | Tan, Hyp option not selected, Inv option not selected | Calculates the tangent of the current value in the display area. | 45 Tan | 1
Arc Tangent `atan` | Tan, Hyp option not selected, Inv option selected | Calculates the arc tangent of the current value in the display area. | 1 Inv Tan | 45
Hyperbolic Tangent `tanh` | Tan, Hyp option selected, Inv option not selected | Calculates the hyperbolic tangent of the current value in the display area. | 0.6 Hyp Tan | 0.537049567
Arc Hyperbolic Tangent `atanh` | Tan, Hyp option selected, Inv option selected | Calculates the arc hyperbolic tangent of the current value in the display area. | 0.6 Hyp Inv Tan | 0.693147181

#### To Calculate Logarithms

To calculate logarithms, use the buttons described in .

##### Calculating Logarithms

Function | Button | Description | Example | Result
--- | --- | --- | --- | ---
Common Logarithm Base 10 | Log10 | Calculates the common logarithm (base 10) of the current value in the display area. | 10 Log10 | 1
Natural Logarithm | Ln | Calculates the natural logarithm of the current value in the display area. | 10 Ln | 2.30
Common Logarithm Base 2 | Log2 | Calculates the common logarithm (base 2) of the current value in the display area. | 10 Log2 | 3.32

Common antilogarithm and natural antilogarithm are not supported in this version of gcalctool.

#### To Perform Bitwise Calculations

To perform bitwise calculations, use the buttons described in .

##### Performing Bitwise Calculations

Function | Button | Description | Example | Result
--- | --- | --- | --- | ---
Bitwise OR | OR | Performs a bitwise OR operation on the current value in the display area and the next number that you enter, treating both numbers as unsigned long integers. | 10001000 OR 00010001 | 10011001
Bitwise AND | AND | Performs a bitwise AND operation on the current value in the display area and the next number that you enter, treating both numbers as unsigned long integers. | 10101010 AND 00110011 | 100010
Bitwise NOT | NOT | Performs a bitwise NOT operation on the current value in the display area, treating the number as an unsigned long integer. | For arithmetic precedence mode: NOT 1357ACE For non-arithmetic precedence mode: 1357ACE NOT | FECA8531
Bitwise XOR | XOR | Performs a bitwise XOR operation on the current value in the display area and the next number that you enter, treating both numbers as unsigned long integers. | 1100 XOR 1010 | 110
Bitwise XNOR | XNOR | Performs a bitwise XNOR operation on the current value in the display area and the next number that you enter, treating both numbers as unsigned long integers. | 1100 XNOR 1010 | 11111111111111111111111111111001

#### To Perform Bit Manipulations on Integers

To change the values of individuals bits in integer values, choose View Show Bit Editor. This option is only available in Scientific mode.

If the calculator display shows an integer value, then each of the bits in that integer value is displayed as a collection of 0's and 1's. By clicking on any of these individual bits, their value can be toggled, causing the displayed integer value to be adjusted accordingly.

#### To Enter Exponential Numbers

To enter exponential numbers, use the Exp button.

The Exp button enables you to enter numbers in scientific notation, that is, mantissa * baseexponent:

mantissa

  Current non-zero value in the display area. If the current value in the display area is zero, the mantissa is 1.0.

base

  2, 8, 10, or 16 for binary, octal, decimal, and hexadecimal numeric base respectively.

exponent

  Next number that you enter.

When you click Exp, the calculator displays `. +` to represent base to the power of the next number that you enter.

To change the sign of the number, use the +/- button before the Exp button. How you change the sign of the exponent (the power to which the number is raised) depends on whether you are in arithmetic precedence mode or not. In arithmetic precedence mode, use - after the Exp button, otherwise use the +/- button after entering the exponent.

To enter a decimal number in exponential format, in arithmetic precedence mode, use the guidelines in the following table:

Number | Enter | Number Displayed
--- | --- | ---
1200000000 | 12 Exp + 8 = | 1200000000
-1200000000 | - 12 Exp + 8 = | -1200000000
0.00000012 | 12 Exp - 8 = | 1.2e-7
-0.00000012 | - 12 Exp - 8 = | -1.2e-7

To enter a decimal number in exponential format, in non-arithmetic precedence mode, use the guidelines in the following table:

Number | Enter | Number Displayed
--- | --- | ---
1200000000 | 12 Exp 8 = | 1200000000
-1200000000 | 12 +/- Exp 8 = | -1200000000
0.00000012 | 12 Exp 8 +/- | 1.2e-7
-0.00000012 | 12 +/- Exp 8 +/- | -1.2e-7

#### To Use Constant Values

Click Con to display the list of defined constant values. All constant values are specified in decimal numeric base, even if the current numeric base is not decimal.

Select a constant from the menu to enter its value in the display area. If you use the keyboard shortcut #, you can use the keyboard to specify the constant, as shown in the following example:

Keyboard Entry | Constant
--- | ---
# 3 | C3

The gcalctool application provides ten default constant values, as described in the following table:

Number | Value | Description
--- | --- | ---
C0 | 0.621 | Kilometer-to-mile conversion factor Multiply the current value in the display area by this constant, to convert from kilometers per hour to miles per hour. For example, 8 * Con C0 = 5. Divide the current value in the display area by this constant, to convert from miles per hour to kilometers per hour. For example, 5 / Con C0 = 8.
C1 | 1.414213562 | Square root of 2
C2 | 2.718281828 | e
C3 | 3.141592653 | pi
C4 | 0.3937007 | Centimeter-to-inch conversion factor Multiply the current value in the display area by this constant, to convert from centimeters to inches. For example, 30 * Con C4 = 12. Divide the current value in the display area by this constant, to convert from inches to centimeters. For example, 12 / Con C4 = 30.
C5 | 57.295779513 | Degrees in a radian
C6 | 1048576 | 2 ^ 20
C7 | 0.0353 | Gram-to-ounce conversion factor Multiply the current value in the display area by this constant, to convert from grams to ounces. For example, 500 * Con C7 = 18. Divide the current value in the display area by this constant, to convert from ounces to grams. For example, 18 / Con C7 = 500.
C8 | 0.948 | Kilojoule-to-British-thermal-unit conversion factor Multiply the current value in the display area by this constant, to convert from kilojoules to British thermal units. For example, 10 * Con C8 = 9.48. Divide the current value in the display area by this constant, to convert from British thermal units to kilojoules. For example, 9.48 / Con C8 = 10.
C9 | 0.061 | Cubic-centimeter-to-cubic-inch conversion factor Multiply the current value in the display area by this constant, to convert from cubic centimeters to cubic inches. For example, 100 * Con C9 = 6.10. Divide the current value in the display area by this constant, to convert from cubic inches to cubic centimeters. For example, 6.10 / Con C9 = 100.

You can overwrite the default constants to store your own constants.

To store a new constant or edit an existing constant, perform the following steps:

1. Click Con, then select Edit Constants from the popup menu.

2. In the Edit Constants dialog, select the constant that you want to overwrite or edit.

3. Click on the Value field, then enter the new value.

4. Click on the Description field, then enter the new description.

5. Click OK to save your changes and close the Edit Constants dialog.

#### To Use Functions

To show the available functions, click Fun. A popup menu displays the list of defined functions. Select a function from the menu to run that function. If the function is not defined, the value zero is returned.

If you use the keyboard shortcut F, you can use the keyboard to specify the function, as shown in the following example:

Keyboard Entry | Function
--- | ---
F 3 | F3

The gcalctool application does not provide any default functions. You can store up to ten functions.

To store a new function or edit an existing function, perform the following steps:

1. Click Fun, then select Edit Functions from the popup menu.

2. In the Edit Functions dialog, select a blank entry, or the function that you want to overwrite.

3. Click on the Value field, then enter the new value. Use the keyboard shortcuts to invoke a gcalctool button. For example, enter `90K` to calculate sine(90).

4. Click on the Description field, then enter the new description. For example, `Sine 90`.

5. Click OK to save your changes and close the Edit Functions dialog.

#### To Manipulate Binary Numbers

To manipulate binary numbers, use the buttons described in .

##### Manipulating Binary Numbers

Function | Button | Description | Example | Result
--- | --- | --- | --- | ---
Left Shift n | < | Shifts the current unsigned 32-bit binary value in the display area, the specified number of places to the left. Click <, then select the number of shift places from the popup menu. The number can be shifted up to 15 places left. | 111 < 1 place | 1110
Right Shift n | > | Shifts the current unsigned 32-bit binary value in the display area, the specified number of places to the right. Click >, then select the number of shift places from the popup menu. The number can be shifted up to 15 places right. | 1011 > 1 place | 101
Get a 16-Bit Unsigned Integer | &16 | Truncates the current value in the display area and returns a 16-bit unsigned integer. | FFFFF &16 | FFFF
Get a 32-Bit Unsigned Integer | &32 | Truncates the current value in the display area and returns a 32-bit unsigned integer. | FFFFFFFFFF &32 | FFFFFFFF

If you use keyboard shortcuts, you can use the keyboard to specify the number of places to shift, as shown in the following examples:

Keyboard Entry | Description
--- | ---
< 4 | Shifts the current binary value in the display area 4 places to the left.
> 4 | Shifts the current binary value in the display area 4 places to the right.

#### To Perform Miscellaneous Scientific Calculations

To perform miscellaneous scientific calculations, use the buttons described in .

##### Performing Miscellaneous Scientific Calculations

Function | Button | Description | Example | Result
--- | --- | --- | --- | ---
e to the x power | ex | Calculates the value of `e` raised to the power of the current value in the display area. | 2 ex | 7.39
10 to the x power | 10x | Calculates the value of 10 raised to the power of the current value in the display area. | 2 10x | 100
x to the y power | xy | Raises the current value in the display area to the power of the next value that you enter. | 2 xy 4 = | 16
x Factorial | x! | Calculates the factorial of the current value in the display area. x factorial is x*(x-1)*(x-2)...*1. This function applies only to positive integers. | 4 x! | 24
Modulus Division | Mod | Divides the current integer value in the display area by the next integer number that you enter, displaying the remainder. | 15 Mod 4 = | 3
Random Number Generator | Rand | Generates a random number in the range 0.0 to 1.0 then displays the random number in the display area. | Rand | 0.14
Hexadecimal Numerals | A to F inclusive | These numerals are available in hexadecimal base only. | B | B

### To Undo and Redo

To undo your previous action, choose Edit Undo . You can undo up to 15 past actions.

If you want to redo an action you just undo'ed, choose Edit Redo . You can redo up to 15 undo'ed actions.

### To Quit

To quit gcalctool, choose Calculator Quit .

When you quit gcalctool, the current values of the following settings are stored and automatically applied the next time you start gcalctool:

- Mode: Basic, Advanced, Financial, or Scientific

- Accuracy

- Memory Registers window displayed or not displayed, plus the contents of each memory register

- Numeric base

- Display type

- Trigonometric type

- Show Trailing Zeroes

- Show Thousands Separator

## Technical Information

### Order of Operations

By default, calculations are performed using arithmetic precedence. That is, the precedence of the arithmetic operators is taken into consideration and the result is only calculated when you click Return.

In the following example, the result of the calculation is 22 because the multiplication operator, `*`, has precedence over the addition operator, `+`.

    4 + 3 * 6 = 22

If you do not wish to apply arithmetic precedence to your calculations, select View Left-to-right Precedence.

If you choose not to apply arithmetic precedence, then the result the calculation in the example is 42 because the calculation is performed from left to right.

### Error Conditions

If you perform an invalid calculation, gcalctool indicates the error condition as follows:

- Displays the word `Error` in the display area.

- Displays an error message in the status bar.

- Makes all calculator buttons unavailable, except Clr.

- Makes all calculator options unavailable.

- Makes all calculator menu items unavailable, except Calculator Quit and Help Contents.

To clear the error condition, click Clr or press Shift Delete.

### Changing Modes

If the user tries to change modes when a partial calculation is being displayed, a warning dialog is displayed, telling the user that the current calculation will be cleared, and the base will be reset to decimal.

There is a checkbox present, that if checked, prevents the dialog from being shown again.

If the user presses the Cancel button, the change mode operation is cancelled. If the user presses the Change Mode button, the mode is changed and has the following side-effects:

- Clears the display.

- Sets the base to decimal.

- Sets the numeric display to fixed.

- Sets the accuracy to nine places after the numeric point.

- Clears the display of the thousands separator.

- Clears the display of trailing zeroes after the numeric point.

- Dismisses the register window if the new mode is Basic.

### Changing The Display Area

In arithmetic precedence mode, it is possible to use the mouse to click on the display area and edit it.

All the normal keyboard shortcuts will work, plus the addition of:

- Ctrl Delete which will delete the character to the right of the text cursor

- Home which moves the text cursor to the beginning of the display area

- End which moves the text cursor to the end of the display area

## Quick Reference: Keyboard Shortcuts

, , and provide a quick reference for all of the gcalctool keyboard shortcuts.

When you use the keyboard shortcut for any of the calculator buttons that have a menu associated with them, that menu is displayed. You can then use the arrow keys to select a menu item or the menu item's shortcut.

### Quick Reference for Keyboard Shortcuts of gcalctool Buttons

Keyboard Shortcut | Button | Function | See
--- | --- | --- | ---
0 to 9 inclusive | 0 to 9 inclusive | Numerals |
A | Acc | Accuracy |
a | A | Hexadecimal numerals |
b | B | Hexadecimal numerals |
C | +/- | Change the arithmetic sign |
c | C | Hexadecimal numerals |
D | Ddb | Double-declining depreciation |
d | D | Hexadecimal numerals |
E | Exp | Exponential |
e | E | Hexadecimal numerals |
F | Fun | Function |
f | F | Hexadecimal numerals |
G | Log | Common logarithm |
i | Int | Integer portion |
J | Cos | Cosine |
K | Sin | Sine |
L | Tan | Tan |
l | Sln | Straight-line depreciation |
M | Mod | Modulus Division |
m | Ctrm | Compounding term |
N | Ln | Natural logarithm |
n | Xnor | Bitwise XNOR |
P | Pmt | Periodic payment |
p | Pv | Present value |
R | Rcl | Retrieve value from memory register |
r | 1/x | Reciprocal |
S | Sto | Store value in memory register |
s | Sqrt | Square root |
T | Rate | Periodic interest rate |
t | Term | Payment period |
u | Abs | Absolute value |
v | Fv | Future value |
X | Exch | Exchange memory register value and displayed value |
Y | Syd | Sum-of-the-years'-digits depreciation |
^ | xy | x to the y power |
! | x! | x factorial |
# | Con | Constant value |
% | % | Percentage |
& | And | Bitwise AND |
( and ) | ( and ) | Parentheses |
* | * | Multiplication |
+ | + | Addition |
- | - | Subtraction |
. | . | Numeric point |
/ | / | Division |
: | Frac | Fractional portion |
< | < | Left shift n |
= or Return | = | Calculate a result |
> | > | Right shift n |
? | Rand | Random number generator |
@ | x2 | Square |
[ | &32 | Get a 32-bit unsigned integer |
] | &16 | Get a 16-bit unsigned integer |
x | Xor | Bitwise XOR |
{ | ex | e to the x power |
| | Or | Bitwise OR |
} | 10x | 10 to the x power |
~ | Not | Bitwise NOT |
Backspace | Bksp | Backspace |
Esc or Ctrl Backspace | CE | Clear entry |
Shift Delete | Clr | Clear |

### Quick Reference for Keyboard Shortcuts of gcalctool Scientific Mode Options

Keyboard Shortcut | Option | Function | See
--- | --- | --- | ---
Alt a | Gradians | Set the trigonometric type to gradians. |
Alt b | Bin | Set the numeric base to binary. |
Alt d | Dec | Set the numeric base to decimal. |
Alt f | Fix | Set the display type to fixed-point format. |
Alt g | Degrees | Set the trigonometric type to degrees. |
Alt i | Inv | Select the inverse option for use with the trigonometric functions. |
Alt n | Eng | Set the display type to engineering format. |
Alt o | Oct | Set the numeric base to octal. |
Alt r | Radians | Set the trigonometric type to radians. |
Alt s | Sci | Set the display type to scientific format. |
Alt x | Hex | Set the numeric base to hexadecimal. |
Alt y | Hyp | Select the hyperbolic option for use with the trigonometric functions. |

### Quick Reference for Keyboard Shortcuts of gcalctool Menu Items

Keyboard Shortcut | Menu Item | Function | See
--- | --- | --- | ---
Ctrl b | View Base | Change to Basic mode |
Ctrl c | Edit Copy | Copy the current value in the display area to the clipboard |
Ctrl e | View Show Bitcalculating Extension | Display the bitcalculation extension |
Ctrl f | View Finanziaria | Change to Financial mode |
Ctrl h | Help Contents | Display the gcalctool online help |
Ctrl i | Edit Insert ASCII Value | Display the Insert ASCII Value dialog |
Ctrl k | View Show Thousands Separator | Display the thousands separator |
Ctrl l | View Left-to-right Precedence | Calculate results using left-to-right precedence |
Ctrl m | View Memory Registers | Display the Memory Registers window |
Ctrl q | Calcolatrice Quit | Quit the gcalctool application |
Ctrl r | View Arithmetic Precedence | Calculate results using arithmetic precedence |
Ctrl s | View Scientifica | Change to Scientific mode |
Ctrl t | View Show Trailing Zeroes | Show trailing zeroes |
Ctrl v | Edit Paste | Paste the current value in the clipboard to the display area |
Ctrl z | Edit Undo | Undo previous action |
Shift Ctrl z | Edit Redo | Redo an undo'ed action |