| T O P I C R E V I E W |
| erman |
Posted - 12/19/2005 : 06:51:08 AM
Origin Version (Select Help-->About Origin):
Operating System:
Hi.
I have some analysis data. Lets say CD vs. time.When I plot the data vs. time, the resutant curve looks like to fit polynomial equation.At first, I tried to find the best equation(y=f(time)) by looking at R square value and absolute standard deviation. Then, I differentiated the equation (dy/dt)by hand and I put every time data in that equation to find the derivation at that point(time(t0)). I realized that there is a differentiate function appears after plotting the curve under the menu of analysis-calculus-differentiate.But, the values I got by finding the best equation and taking the derivation by hand were not even close to the data obtained from using origin differantiate function.
Could anybody tell me how origin`s differantiate function works? Am I following the wrong way to find the differentiated form of my data?
Thank you for considering....
ERMAN |
| 1 L A T E S T R E P L I E S (Newest First) |
| easwar |
Posted - 12/19/2005 : 11:51:52 AM
Hi Erman,
Origin performs numerical differentiation by averaging the slopes of two adjacent data points. You can look at the help file and the section:
Analysis:Advanced Math on Data Sets: Differentiation and Integration
for the formula.
If you compare the numerically computed derivative with the derivative of some function that fit the data, those could be different. Best to send your details to tech support so that we can take a look. Please mention which version you are using in your e-mail to tech.
Easwar
OriginLab
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