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Math Help - N(t) = γA(t)

  1. #1
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    N(t) = γA(t)

    This should be easy if you know what to do. I just don't.

    N(t) = γA(t)

    N(t) is a known number (of peatlands) at time t, A(t) is a known area (deglaciated) at time t. γ is an unknown number (of peatlands that can form per unit of deglaciated area). How do I decide what is the one best fit value for γ for a range of N's and A's? This needs some kind of computer programme to calculate it?
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  2. #2
    Grand Panjandrum
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    Quote Originally Posted by etsija View Post
    This should be easy if you know what to do. I just don't.

    N(t) = γA(t)

    N(t) is a known number (of peatlands) at time t, A(t) is a known area (deglaciated) at time t. γ is an unknown number (of peatlands that can form per unit of deglaciated area). How do I decide what is the one best fit value for γ for a range of N's and A's? This needs some kind of computer programme to calculate it?
    So:

    y=\frac{N(t)}{A(t)}

    so compute the average of the ratio of N(t) to A(t) for the data you have and use that.

    If you know a bit about the errors in the known N's and A's you could do a bit more.

    RonL
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  3. #3
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    Average, that makes sense. Thanks a lot. The article I'm reading (Gorham et al 07) says about their dataset "No value of y allowed this simplest model to fit the data adequately". That made me think I should somehow try a number of values to find the fittest, but perhaps it just means different average values like mean and median?

    Anyway, it seems to work now. I calculated the mean, used it for a simple model (mean*A(t)), correlated that with the actual data N(t) and got a realistic R2.
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