Programmer Guide/Command Reference/EVAL/log: Difference between revisions
From STX Wiki
< Programmer Guide | Command Reference | EVAL
Jump to navigationJump to search
No edit summary |
No edit summary |
||
| Line 20: | Line 20: | ||
Example: | Example: | ||
<pre> | <pre> | ||
#a := eval | #a := eval 20*log(2) // convert factor 2 to 6dB | ||
#b := eval | #b := eval 20*log(2,10) // same as above | ||
#c := eval | #c := eval 20*log(fill(2,10,20,50,100)) | ||
// | // $#c = { 6.02, 20, 26.02, 33.98, 40 } | ||
</pre> | </pre> | ||
[[Programmer_Guide/Command_Reference/EVAL#Functions|<function list>]] | [[Programmer_Guide/Command_Reference/EVAL#Functions|<function list>]] | ||
Revision as of 13:56, 6 April 2011
Compute the logarithm of the argument x element by element.
- Usage
log(x , b)general logarithm to base b log(x)common logarithm (base 10) ln(x)natural logarithm (base e) alias: log(x,e)ld(x)logarithm to the base 2 alias: log(x,2)
- x
- a scalar, vector or matrix; all elements must be greater than 0
- b
- the base of the logarithm; must be a positive number
- Result
- The result r has the same type as x and contains the logarithm of x to the specified base b, computed element by element.
- See also
- npow2, exp, lin2log, log2lin
- Note
- For the inverse function the operater ^ can be used; e.g.: 10^x, e^x, ...
Example:
#a := eval 20*log(2) // convert factor 2 to 6dB
#b := eval 20*log(2,10) // same as above
#c := eval 20*log(fill(2,10,20,50,100))
// $#c = { 6.02, 20, 26.02, 33.98, 40 }
