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sinh/cosh miscalculation? - Сообщения
#1 Опубликовано: 21.04.2010 13:41:20
Hello (again)
I posted before but it didn't show up. I won't insist.
However, I may have found a bug, if it's not, please disregard this. I uploaded the file to:
" http://www.easy-share.com/1909986260/Inv.%20Chebyshev.sm " [edit]the link didn't show up properly[/edit]
I'm trying to recreate the files from wxMaxima and I have the denominator as:
wxMaxima: D(k):=1/(sin(x(k))^2*sinh(y)^2+cos(x(k))^2*cosh(y)^2)
SMath: D(k):=1/{sin(x(k))^2*sinh(y)^2+cos(x(k))^2*cosh(y)^2}
wxMaxima: D(1)=.113545
SMath: D(1)=0.0662
I tried with symbolical evaluation:
wxMaxima: 1/(sinh(asinh(3*sqrt(1111))/3)^2/4+(3*cosh(asinh(3*sqrt(1111))/3)^2)/4)
SMath: 16/{4*sinh(asinh(sqrt(9999))/3)^2+12*cosh(asinh(sqrt(9999))/3)^2}
which are one and the same. Is this a bug or am I doing something wrong?
Regards,
Vlad.
PS: I'm using Ubuntu Karmic x64.
[EDIT2]
sinh seems to be the problem:
Maxima: sinh(y)=2.83849
SMath: sinh(y)=5.7625
y=(1/3)*asinh(sqrt(10^(40/10)-1)) and is the same in both programs: 1.7661
[/EDIT2]
[EDIT3, and last]
On http://smath.info/live/?lang=eng x=17661/10000 and sh(x)=2.8385
[/EDIT3]
I posted before but it didn't show up. I won't insist.
However, I may have found a bug, if it's not, please disregard this. I uploaded the file to:
" http://www.easy-share.com/1909986260/Inv.%20Chebyshev.sm " [edit]the link didn't show up properly[/edit]
I'm trying to recreate the files from wxMaxima and I have the denominator as:
wxMaxima: D(k):=1/(sin(x(k))^2*sinh(y)^2+cos(x(k))^2*cosh(y)^2)
SMath: D(k):=1/{sin(x(k))^2*sinh(y)^2+cos(x(k))^2*cosh(y)^2}
wxMaxima: D(1)=.113545
SMath: D(1)=0.0662
I tried with symbolical evaluation:
wxMaxima: 1/(sinh(asinh(3*sqrt(1111))/3)^2/4+(3*cosh(asinh(3*sqrt(1111))/3)^2)/4)
SMath: 16/{4*sinh(asinh(sqrt(9999))/3)^2+12*cosh(asinh(sqrt(9999))/3)^2}
which are one and the same. Is this a bug or am I doing something wrong?
Regards,
Vlad.
PS: I'm using Ubuntu Karmic x64.
[EDIT2]
sinh seems to be the problem:
Maxima: sinh(y)=2.83849
SMath: sinh(y)=5.7625
y=(1/3)*asinh(sqrt(10^(40/10)-1)) and is the same in both programs: 1.7661
[/EDIT2]
[EDIT3, and last]
On http://smath.info/live/?lang=eng x=17661/10000 and sh(x)=2.8385
[/EDIT3]
#2 Опубликовано: 21.04.2010 14:18:03
Hello.
Thank you for figuring it out! This is a bug of sinh(..) function. I will fix it of cause, but for now I can suggest a solution: you need to override sinh(x) function on top of the page. Here is the screen:

Sorry for this error
Best regards.
Thank you for figuring it out! This is a bug of sinh(..) function. I will fix it of cause, but for now I can suggest a solution: you need to override sinh(x) function on top of the page. Here is the screen:
Sorry for this error

Best regards.
#3 Опубликовано: 21.04.2010 14:19:37
I said I won't edit anymore, so I'm replying...
Using (e^y +/- e^-y)/2 gives the true result. Just thought I'd let you know.
[EDIT]
We seem to have posted in ~the same time
Good luck and thank you for this wonderful alternative to Mathcad.
Kind regards,
Vlad.
[/EDIT]
Using (e^y +/- e^-y)/2 gives the true result. Just thought I'd let you know.
[EDIT]
We seem to have posted in ~the same time

Good luck and thank you for this wonderful alternative to Mathcad.
Kind regards,
Vlad.
[/EDIT]
#4 Опубликовано: 21.06.2010 20:52:48
Sinh(..) function calculation fixed. Fix will be available with a new version of SMath Studio. For now, you can test calculation using SMath Studio Live.
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