2009-04-02 12:26:55 +02:00
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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
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<html lang="en">
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<head>
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<title>TTCalc - accuracy</title>
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<link rel="stylesheet" href="styles.css" type="text/css">
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<object type="application/x-oleobject" classid="clsid:1e2a7bd0-dab9-11d0-b93a-00c04fc99f9e">
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<param name="Keyword" value="accuracy">
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</object>
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</head>
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<body>
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<h1>Accuracy</h1>
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<p>
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TTCalc uses binary floating point numbers. It means that your input values are first
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converted to a binary representation and then the calculations are performed. After
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calculating the result is again converted from the binary to the decimal (you can
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select the input and output format on the display tab). You must remember that not
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all values can be converted from binary to decimal (and vice versa) without loosing
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accuracy. For example decimal '5' can be converted to binary '101' and the '101' is
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exactly equal decimal 5. But decimal '0.3' has not a good binary representation, it
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is '0.010011001100110011.....'. And when you put decimal '0.3' the calculations are
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performed on an approximate value and the result is only an approximation too.
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</p>
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<p>
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For example try to calculate: 0.204 - 0.34*0.80 + 0.068, you would expect that the
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2009-11-01 21:34:10 +01:00
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result was 0 but TTCalc gives you: 3.15544362088404722164691426e-30 which is
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2009-04-02 12:26:55 +02:00
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a good approximation to the real zero (look at e-30 part which means 10^(-30)).
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</p>
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</body>
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</html>
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