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maus3r
Belgium
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 Posted - 11/23/2007 : 07:33:39 AM
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I tried to fit some data of an experiment. I defined my own finktion: y=D/(sin(x))^4
but when I try to fit it, it doesn't work. Is there any Problem with the sinus about degree and radiation, because I used degree in my data?
My Data:
angle [] Counts [ ]
30 0,05
25 0,10
20 0,25
15 1,07
10 8,60
5 34,8
0 51,6
-5 52,0
-10 42,4
-15 17,2
-20 2,17
-25 0,43
-30 0,16
My Intention is to fit it to a function that is proportional to 1/(sin(x))^4 like Rutherford.
And if thats possible get an angle-correction, because the data is not symmetric to 0.
Thank you for any help ! |
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Mike Buess
USA
3037 Posts |
Posted - 11/23/2007 : 08:08:13 AM
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If you use Origin 7 or higher you are probably defining your function in Origin C, in which all triginometric arguments must be in radians. Just define you function as y = D / sin(x*pi/180.0).
Mike Buess
Origin WebRing Member |
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maus3r
Belgium
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Posted - 11/23/2007 : 08:15:50 AM
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Okay thanks I just changed my function to y = D/(sin(x*pi/180.0))^4 , but I still don't get any graph when I try to fit it with my self defined Funktion.
Is there anything else I have to do to get a better result ? |
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Mike Buess
USA
3037 Posts |
Posted - 11/23/2007 : 08:24:28 AM
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Your function works fine for me although it doesn't fit the data very well. (Looks like you need a parameter to offset the center.) Perhaps you didn't initialize the parameter D? Starting out with D=1 works fine.
Mike Buess
Origin WebRing Member |
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maus3r
Belgium
Posts |
Posted - 11/23/2007 : 08:44:13 AM
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how can I initialize the parameter D ?? sorry its my very first time I work with this program.
thank you, I just got it put 1 to "value", thank you very much ill try myself to get the result better ;)
Edited by - maus3r on 11/23/2007 08:53:16 AM |
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Problem with using a non-standard function