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mingkeng
China
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 Posted - 10/09/2007 : 04:46:52 AM
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Origin Version (Select Help-->About Origin): OriginPro 7.5
Operating System: XP sp2
I am a new user of using the curve fitting. I have a sort of number:
x | y
-10 | 0.3942
-5 | 0.3912
0 | 0.3869
5 | 0.3759
10 | 0.3454
15 | 0.3149
20 | 0.3066
25 | 0.3022
30 | 0.2993
I want to fit the number into the function as follows
y=d0+d1*tanh[d2*(x-d3)]
d0d1d2d3 are the parameters.
I use the fitting wizard, but I cannot find the Hyperbolic Tangent function. What shall I do?
Help please, thanks!
Edited by - mingkeng on 10/09/2007 07:24:33 AM
Edited by - mingkeng on 10/09/2007 07:25:37 AM |
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Fay_Guo
China
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Posted - 10/09/2007 : 9:50:36 PM
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Hi,
Could you try to use Advanced Fitting Tools? From that you can define the functions as what you want.
In addition, I'm sorry to tell you that your definition should be defined as
y=d0+d1*tanh(d2*(x-d3))
Thanks
Fay
OriginLab Technical Service |
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mingkeng
China
Posts |
Posted - 10/10/2007 : 9:02:24 PM
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| Thanks for your help! |
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casadyb
USA
1 Posts |
Posted - 11/06/2014 : 3:42:00 PM
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Hi mingkeng,
I am just delving into fitting the hyperbolic function to a set of data - however, this is the first instance of the formula I have found with the necessary parameters (intercept, slope and inflection point, namely).
From this formula: y=d0+d1*tanh(d2*(x-d3))can you tell me what the parameters are? For example, with some test data it looks like d3 is the point of subjective equality (when y=.5).
I greatly appreciate your help! |
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greg
USA
1378 Posts |
Posted - 11/07/2014 : 10:12:53 AM
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I don't know the technical names (which probably vary with industry or discipline), but I would refer to them as:
Inflection Point Y (d0), Magnitude (d1), Shape Factor (d2), Inflection Point X (d3)
So the resultant curve would have a minimum value of d0 - d1 and a maximum of d0 + d1 and have an inflection point ( derivative slope = 0 ) at (d3, d0).
As d2 decreases from about 0.5, the transition becomes more gradual; as d2 increases from about 0.5, the transition becomes sharper.
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Problem about curve fitting from a new user