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shaharsu2
1 Posts |
 Posted - 05/05/2011 : 05:34:14 AM
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Hi all,
I'm trying to create a non linear curve fitting function that looks like this:
y = C * (x(i) - x(i-1))
with x(i) being the "current" value and x(i-1) being the "previous" value for each data point.
Any idea how I can achieve this?
Thanks in advance!
Shahar.
Origin Ver. 8.1 and Service Release 1
Operating System: WinXP |
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Penn
China
644 Posts |
Posted - 05/05/2011 : 10:23:37 PM
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Hi Shahar,
Maybe you can try to create a fitting function with two independent variables, such as y = C*(x1-x2), where x1 is for the "current" value and x2 for the "previous" value.
And then you can add a new column to worksheet, copy the x column and paste to this new column from the second row, then fill the first row with the desired value, such 0, and delete the last row. So, when performing nonlinear fit, the x column is for x1 variable, and the newly created column is for x2 variable.
Please refer to this tutorial on how to perform fitting with multiple independent variables.
Penn |
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NL cruve fit using previous rows