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calculating kde
howto perform simple and complex calculations and unit conversions in kde
For quick calculations or unit conversions, there are a couple of options for your kde desktop. I've always wondered why calculator applications on computers insist on emulating the classic casio calculator interface. The traditional calculator interface is limited by a lack of keys, and an lcd display. Why shoehorn an application that has all the power and flexibility of a full blown computer into such a constricted interface? Luckily a few developers (including myself) have seen the folly of limiting calculator interfaces to a numeric keypad. First the simple/ubiquitous one.
alt+f2
When you press alt+f2 on a kde desktop, you get this:
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Normally, you would use alt+f2 to launch an application, or launch a kioslave. However, you can also use it to do basic calculations. For example:
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gives:
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speedcrunch
Speedcrunch is a calculator application that supports both the traditional casio calculator interface, and a keyboard interface. It provides limited "scientific calculator" functionality as will. Past calculations are displayed above the input bar for later recall. Speedcrunch is also cross-platform, and works on windows and mac-osx.
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sKalcuverter
sKalcuverter is a superkaramba theme, which provides easy access to the google calculator/converter functionality.
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You can do basic calculations (like the other apps above), which are processed immediately through the python interpreter. However, you can do more complicated calculations which are processed through the google web calculator. Enter a calculation, and sKalcuverter will go out to the web, and get the answer for you. For example:
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This example is a calculation involving the sin function and the e logarithmic constant. sKalcuverter understands all sorts of math functions and constants, as well as physical constants (like h:Planck's constant, c:speed of light in a vacuum, G:gravitational constant).
But one of the really cool features of sKalcuverter is that it will do unit conversions. For example:
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You can also re-perform any of the last 10 calculations through the dropdown history list:
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If you want to use the last answer in your next calculation, just insert the keyword ans. In addition, it will do parenthesis matching and syntax checking.
date calculations
Sometimes you need to know how many days there are between two dates, or know what the date will be 15 working days from today. date calculator is a small application that provides the ability to do calculations with dates. You can work out the interval between two dates, or add and subtract a number of days to or from a date. You can also do the calculation based on working days and inclusive or exclusive of the end dates.
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There is a comprehensive gui for setting holidays. You can do set fixed date holidays like Christmas, or variable date holidays such as "the first Monday in October" or "the closest Tuesday to 14 December". Finally, you can set the easter holidays, which are lunar based.
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conclusion
With the above tools, you'll be all set to do the simplest and most complex calculations and conversions.
You can discuss this howto on the forums.