Qalculate! GTK UI

Qalculate! is a multi-purpose cross-platform desktop calculator. It is simple
to use but provides power and versatility normally reserved for complicated
math packages, as well as useful tools for everyday needs (such as currency
conversion and percent calculation). Features include a large library of
customizable functions, unit calculations and conversion, symbolic calculations
(including integrals and equations), arbitrary precision, uncertainty
propagation, interval arithmetic, plotting, and a user-friendly interface (GTK, 
Qt, and CLI).

1. Requirements

* GTK (>= 3.10)
* libqalculate (>= 5.5.0)

2. Installation

Instructions and download links for installers, binaries packages, and the
source code of released versions of Qalculate! are available at
https://qalculate.github.io/downloads.html.

In a terminal window in the top source code directory run

* ./autogen.sh
  (not required if using a release source tarball, only if using the git
  version)
* ./configure
* make
* make install (as root, e.g. sudo make install)

If libqalculate has been installed in the default /usr/local path you it might
be necessary to specify the pkgconfig path when running configure using
PKG_CONFIG_PATH=/usr/local/lib/pkgconfig ./configure

The resulting executable is named qalculate-gtk.

3. Features

Features specific to qalculate-gtk:

* Graphical user interfaces implemented using GTK 3
* Flexible expression entry with customizable completion, hints, and continious
  display of parsed expression
* Optional calculate-as-you-type mode
* Small and ... not so small mode
* Calculation history which allows the user to access the text and value of and
  apply operations to previous expressions and result
* Optional traditional calculator keypad, with quick access to most features,
  and a programming mode
* Practical menus give fast access to all advanced features
* Customizable meta modes for quickly switching between different settings
* Dialogs for management of and easy access to functions, variables and units
  (with quick conversion)
* User friendly dialogs for functions, with description and entries for
  arguments
* Create/edit functions, variables and units
* Easy editing of matrices and vectors
* Various tools for fast conversion between number bases, floating point
  conversion, calendar conversion, and percentage calculation, and a period
  table
* Convenient interface to gnuplot
* Configurable keyboard shortcuts
* and more...

Features from libqalculate:

* Calculation and parsing:
   * Basic operations and operators:
     + - * / mod ^ E () && || ! < > >= <= != ~ & | << >> xor
   * Fault-tolerant parsing of strings:
     log 5 / 2 .5 (3) + (2( 3 +5 = ln(5) / (2.5 * 3) + 2 * (3 + 5)
   * Expressions may contain any combination of numbers, functions, units,
     variables, vectors and matrices, and dates
   * Supports complex and infinite numbers
   * Propagation of uncertainty
   * Interval arithmetic (for determination of the number of significant digits
     or direct calculation with intervals of numbers)
   * Supports all common number bases, as well as negative and non-integer
     radices, sexagesimal numbers, time format, and roman numerals
   * Ability to disable functions, variables, units or unknown variables for
     less confusion: e.g. when you do not want (a+b)^2 to mean (are+barn)^2 but
     ("a"+"b")^2
   * Controllable implicit multiplication
   * Matrices and vectors, and related operations (determinants etc.)
   * Verbose error messages
   * Arbitrary precision
   * RPN mode
* Result display:
   * Supports all common number bases, as well as negative and non-integer
     radices, sexagesimal numbers, time format, and roman numerals
   * Many customization options: precision, max/min decimals, complex form,
     multiplication sign, etc.
   * Exact or approximate: sqrt(32) returns 4 * sqrt(2) or 5.66
   * Simple and mixed fractions: 4 / 6 * 2 = 1.333... = 4/3 = 1 + 1/3
* Symbolic calculation:
   * E.g. (x + y)^2 = x^2 + 2xy + y^2; 4 "apples" + 3 "oranges"
   * Factorization and simplification
   * Differentiation and integration
   * Can solve most equations and inequalities
   * Customizable assumptions give different results
     (e.g. ln(2x) = ln(2) + ln(x) if x is assumed positive)
* Functions:
   * Hundreds of flexible functions: trigonometry, exponents and logarithms,
     combinatorics, geometry, calculus, statistics, finance, time and date,
     etc.
   * Can easily be created, edited and saved to a standard XML file
* Units:
   * Supports all SI units and prefixes (including binary), as well as imperial
     and other unit systems
   * Automatic conversion: ft + yd + m = 2.2192 m
   * Explicit conversion: 5 m/s to mi/h = 11.18 miles/hour
   * Smart conversion: automatically converts 5 kg*m/s^2 to 5 N
   * Currency conversion with retrieval of daily exchange rates
   * Different name forms: abbreviation, singular, plural (m, meter, meters)
   * Can easily be created, edited and saved to a standard XML file
* Variables and constants:
   * Basic constants: pi, e, etc.
   * Lots of physical constants (with or without units) and properties of
     chemical element
   * CSV file import and export
   * Can easily be created, edited and saved to a standard XML file
   * Flexible - may contain simple numbers, units, or whole expressions
   * Data sets with objects and associated properties in database-like
     structure
* Plotting:
   * Uses Gnuplot
   * Can plot functions or data (matrices and vectors)
   * Ability to save plot to PNG image, postscript, etc.
   * Several customization options
* and more...

