CalculateTransmission error propagation

[mantid-builder]

Original Reporter: Gesner Passos

While I was working on a ticket related to CalculateTransmission I've spotted an error on how we calculate the error propagation.

 // Take the log of each datapoint for fitting. Recalculate errors remembering that d(log(a))/da  = 1/a
      E[i] = std::abs(E[i]/Y[i]);
      Y[i] = std::log10(Y[i]);

In reality, d(log(a))/da = 1/(a*ln10) this means, that we should have this lines:

 // Take the log of each datapoint for fitting. Recalculate errors remembering that d(log(a))/da  = 1/(a*ln10)
      E[i] = 0.434*std::abs(E[i]/Y[i]);
      Y[i] = std::log10(Y[i]);

[mantid-builder]

This issue was originally trac ticket 9011

[mantid-builder]

http://trac.mantidproject.org/mantid/raw-attachment/ticket/9011/check9011.py
(uploaded by Gesner Passos on 2014-03-05T10:44:55)

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