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HirakChatterjee1-Visitor
1-Visitor
Jun 12, 2014 2:17 PM UTC
Solved

Solving Kramers- Kronig from absorbance: Difficulty in loess function

Hi,

I was to solve Kramers -Kronig relationship and find out the del n value. but the problem is it cant read the o matrix. here is the file attaced. Please help.

Werner_E
Werner_EAnswer
25-Diamond I
Jun 12, 2014 3:36 PM UTC

but the problem is it cant read the o matrix

What do you mean by that?

Did you create that sheet yourself and is the Excel file still in the same directory as the Mathcad file?

ad loess() is failing to converge: according to the help, span should be greater than 1/n, which in your case means span>0.014. You value of span is 0.002 and so is far too small. Increase the value of span accordingly and see if it helps. We cannot try as of the missing Excel file.

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4 replies

MikeArmstrong1-Visitor
1-Visitor
Jun 12, 2014 2:20 PM UTC

Please upload the excel worksheet containing the data.

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    Werner_E
    Werner_E25-Diamond IAnswer
    25-Diamond I
    Jun 12, 2014 3:36 PM UTC

    but the problem is it cant read the o matrix

    What do you mean by that?

    Did you create that sheet yourself and is the Excel file still in the same directory as the Mathcad file?

    ad loess() is failing to converge: according to the help, span should be greater than 1/n, which in your case means span>0.014. You value of span is 0.002 and so is far too small. Increase the value of span accordingly and see if it helps. We cannot try as of the missing Excel file.

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      RichardJ19-Tanzanite
      19-Tanzanite
      Jun 12, 2014 6:34 PM UTC

      You need to increase span to 0.09. Your integral will still not work though, because you need to sort out your scaling for the limits. You are trying to force loess to extrapolate, which it can't do.

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        HirakChatterjee1-VisitorAuthor
        1-Visitor
        Jul 31, 2014 8:23 AM UTC

        Hi Freinds,

        Thank you for your kind replies.

        here are the data file and the mathcad worksheet

        I cant set the limits.So that it fails to converge.

        Help

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