Qalculate!

Qalculate! is a very powerful and easy to use desktop calculator.

This utility is small and simple to use but with much power and versatility under the bonnet. Its features include customizable functions, units, arbitrary precision, plotting, and a graphical interface that uses a one-line fault-tolerant expression entry (although it supports optional traditional buttons).

The center of attention in Qalculate! is the expression entry. Instead of entering each number in a mathematical expression separately, you can directly write the whole expression and later modify it. Just enter an expression as you would write it on paper, press Enter and voila!

Qalculate! also has some special tools to increase efficiency, including a number base conversion dialog and a simple plotting interface.

Plotting in Qalculate! is done through an external program, gnuplot.

Qalculate! 0.9.7

Price Free to download Size 1.4MB License GNU GPL v2 Developer Niklas Knutsson Website qalculate.sourceforge.net System Requirements CLN Libxml2 2.3.8 or higher Glib 2.x gnuplot 1.7 GTK+ 2.4 Libglade 2.0 ScrollKeeper Yelp and libgnome 2.0 GNU Readline groff ImageMagick libcin libnetpbm netpbm psutils qalc libqalculate for KDE kdelibs 3.x Qt 3.1 or higher Support Sites: Forums, Mailing Lists, SourceForge Project Page Selected Reviews: Softpedia

Features include:

• Graphical user interfaces implemented using KDE or GTK+-2.0 and Glade XML
• Flexible expression entry and separate result display
• Displays whether result is precise or not
• Small and ... not so small mode
• Practical menus give fast access to all advanced features
• Calculation history
• Optional traditional calculator buttons
• 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
• Easy interface to gnuplot
• Separate window for fast conversion between number bases
• Periodic table
• Small separate utilities for base, currency and unit conversion
• Additional text based interface with full functionality
• Enhanced completion
• Meta modes

• Calculation and parsing:
  • Basic operations and operators: + - * / ^ E () && || ! < > >= <= != ~ & | << >>
  • 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
  • Supports complex and infinite numbers
  • Supports all number bases from 2 to 36, time format and roman numerals
  • Ability to disable functions, variables, units or unknown variables for less confusion: ex. 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 number bases from 2 to 36, plus sexagesimal numbers, time format and roman numerals
  • Many customization options: precision, max/min decimals, multiplication sign, etc.
  • Exact or approximate
  • Fractions: 4 / 6 * 2 = 1.333... = 4/3 = 1 + 1/3
• Symbolic calculation:
  • Ex. (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 (ex. ln(2x) = ln(2) + ln(x) if x is assumed positive)
• Functions:
  • All the usual functions: sine, log, etc... : ln 5 = 1.609; sqrt(tan(20) - 5) = sqrt(-2.76283905578)
  • Lots of statistical, financial, geometrical, and more functions (approx. 200)
  • If..then..else function, optional arguments and more features for flexible function creation
  • Can easily be created, edit 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
  • Implicit conversion: 5m/s to mi/h = 11.18 miles/hour
  • Smart conversion: can automatically convert 5 kg*m/s^2 to 5 newton
  • Currency conversion with retrieval of daily exchange rates
  • Different name forms: abbreviation, singular, plural (m, meter, meters)
  • Can easily be created, edit and saved to a standard XML file
• Variables and constants:
  • Basic constants: pi, e
  • Lots of physical constants and elements
  • CSV file import and export
  • Can easily be created, edit and saved to a standard XML file
  • Flexible, can 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

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Last Updated Sunday, February 05 2012 @ 01:01 PM EST