Difference between revisions of "LogTen"

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[[Category:Math Functions]]
 
[[Category:Math Functions]]
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[[Category:Functions that operate on complex numbers]]
 
[[Category:Doc Status C]] <!-- For Lumina use, do not change -->
 
[[Category:Doc Status C]] <!-- For Lumina use, do not change -->
  
The base-10 logarithm.
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== LogTen(x) ==
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The base-10 logarithm of «x».  This the the value ''y'' such that ''10^y = x''.
  
= See Also =
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Unless [[EnableComplexNumbers|complex numbers are enabled]], the parameter «x» must be must be non-negative or a warning will result.  If [[Preferences|Show Result Warnings]] is off, or the warning is ignored, the result is [[NaN]].
  
* [[Ln]](X) : The natural logarithm.
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When [[EnableComplexNumbers|complex numbers are enabled]], negative «x» values result in a result that is a complex number.
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== Library ==
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Math functions
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== Examples ==
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:<code>LogTen(0) &rarr; -INF</code>
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:<code>LogTen(0.01) &rarr; -2</code>
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:<code>LogTen(1) &rarr; 0</code>
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:<code>LogTen(1K) &rarr; 3</code>
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:<code>LogTen(729)/LogTen(9) &rarr; 3</code>
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== Complex numbers ==
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When «x» is negative or complex, the result of [[LogTen]](x) is a complex number.  If you want [[LogTen]] to return a complex number for a negative parameter, you must set the system variable [[EnableComplexNumbers]] to 1, otherwise a warning is issued with a result of [[NaN]].  To set [[EnableComplexNumbers]], see [[EnableComplexNumbers|enabling complex numbers]].
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A complex number can be written in polar form as <math>r e^{\theta j}</math>. Thus, <math>\log x = \log r + {\theta\over{\log(10)}} j</math>.  In other words, the real part of the result is the log magnitude, and the imaginary part is proportional to phasor angle, where <math>\theta</math> is written here as if in radians.
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:<code>LogTen(-1) &rarr; 1.364j    { When EnableComplexNumbers is 1 }</code>
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:<code>LogTen(1000j) &rarr; 3+0.682j </code>
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== See Also ==
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* [[Ln]](X) : The natural logarithm
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* [[ProductLog]]
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* [[Exp]](x)
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* [[Complex Numbers]]

Latest revision as of 21:38, 17 February 2016


LogTen(x)

The base-10 logarithm of «x». This the the value y such that 10^y = x.

Unless complex numbers are enabled, the parameter «x» must be must be non-negative or a warning will result. If Show Result Warnings is off, or the warning is ignored, the result is NaN.

When complex numbers are enabled, negative «x» values result in a result that is a complex number.

Library

Math functions

Examples

LogTen(0) → -INF
LogTen(0.01) → -2
LogTen(1) → 0
LogTen(1K) → 3
LogTen(729)/LogTen(9) → 3

Complex numbers

When «x» is negative or complex, the result of LogTen(x) is a complex number. If you want LogTen to return a complex number for a negative parameter, you must set the system variable EnableComplexNumbers to 1, otherwise a warning is issued with a result of NaN. To set EnableComplexNumbers, see enabling complex numbers.

A complex number can be written in polar form as [math]\displaystyle{ r e^{\theta j} }[/math]. Thus, [math]\displaystyle{ \log x = \log r + {\theta\over{\log(10)}} j }[/math]. In other words, the real part of the result is the log magnitude, and the imaginary part is proportional to phasor angle, where [math]\displaystyle{ \theta }[/math] is written here as if in radians.

LogTen(-1) → 1.364j { When EnableComplexNumbers is 1 }
LogTen(1000j) → 3+0.682j

See Also

Comments


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