Can I use logarithms in math equations?
And where in the world are the free resorces to look at other dictionaries? Everything costs money!!!
A bit as UNIX and you solve your issue. BASH script as follows
set TheNumber to 100
set TheLog to (do shell script ("echo 'l(" & (TheNumber as string) & ")' | bc -l")) as real
display dialog TheLog as string
do shell script "man -t bc | open -f -a /Applications/Preview.app"
The square root, cos, sin and other
Basic UNIX is here
http://www.ss64.com/osx/index.html
Advanced UNIX is here
http://developer.apple.com/documentation/Darwin/Reference/ManPages/index.html#//apple_ref/doc/framework/manpages
This seems to only allow natural logarithms to the base āeā. Iām looking for the common logarithm to the base ā10.ā I didnāt see such an option in the pdf file. Is the common logarithm not a part of unix?
log10 is part of math library and is on Apple Developer site above and you can get a āmanā on it
do shell script "man -t log10 | open -f -a /Applications/Preview.app"
I donāt know how to load math library to run log10, maybe someone smarter at UNIX would know.
Have Fun
Thereās lots of free stuff. Check out Satimage osax:
http://www.satimage.fr/software/en/downloads_osaxen.html
gl,
If all you can get is the natural log, then a little math converts that to the base 10 log
with this equationā¦ log(x) = ln(x) / ln(10)
log10(100)
on log10(TheNumber)
set natural_log to (do shell script ("echo 'l(" & (TheNumber as string) & ")' | bc -l")) as real
set natural_log_of_10 to (do shell script ("echo 'l(10)' | bc -l")) as real
set common_log to natural_log / natural_log_of_10
return common_log
end log10
Deivy has a set of editable/readable math functions posted in ScriptBuilders called āMatematica3ā that do not (as I recall) use shell calls to get the answers.
Still no built in support for this in AS?
Here is a log function I wrote using this paper on log algorithms.
on logb(base, x)
local i, n, p, q, ln, ln1, pln, pq, pp, ppq, ppp, tmp
set ln1 to 0
repeat while (base ^ ln1) ā¤ x
set ln1 to ln1 + 1
end repeat
set ln1 to ln1 - 1
set x to x / (base ^ ln1)
if x > 1 then
set pln to x
set fr to true -- fr is First Run (a boolean)
repeat
set n to 0
repeat while (x ^ n) < base
set n to n + 1
end repeat
set n to n - 1
set tmp to x
set x to base / (x ^ n)
set base to tmp
if fr then -- check if First Run
set p to 1
set q to n
set ppp to 0
set ppq to 1
set fr to false
else
set p to ppp + n * pp
set q to ppq + n * pq
set ppp to pp
set ppq to pq
end if
set pp to p
set pq to q
set ln to p / q
set tmp to ln - pln
if tmp < 0 then set tmp to -tmp
if tmp < 1.0E-20 then
exit repeat
end if
set pln to ln
end repeat
else
set ln to 0
end if
return ln + ln1
end logb
here is a natural log function
on ln(x) -- https://www.codeproject.com/tips/311714/natural-logarithms-and-exponent
local N, P, L, R, A, E
set E to "2.71828182845904523536" as real --2.718281828459
set P to x
set N to 0
repeat while P ā„ E
set P to P / E
set N to N + 1
end repeat
set N to N + (P / E)
set P to x
repeat
set A to N
set L to (P / (E ^ (N - 1.0)))
set R to (N - 1.0) * E
set N to (L + R) / E
if N = A then exit repeat
end repeat
return N
end ln
or fastest so far is using the equation log(x) = ln(x) / ln(10) ā for any base
on logb(base, x)
script L
property E : "2.71828182845904523536" as real
on ln(x) -- https://www.codeproject.com/tips/311714/natural-logarithms-and-exponent
local N, P, L, R, A
set P to x
set N to 0
repeat while P ā„ E
set P to P / E
set N to N + 1
end repeat
set N to N + (P / E)
set P to x
repeat
set A to N
set L to (P / (E ^ (N - 1.0)))
set R to (N - 1.0) * E
set N to (L + R) / E
if N = A then exit repeat
end repeat
return N
end ln
end script
return (L's ln(x)) / (L's ln(base))
end logb
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