Recent content by scantor145

I need help in devising a procedure to determine the molar absorptivity of an iron-dye complex in two solutions at a wavelength of 660nm. I have a UV-VIS spectrophotometer. Solution 1 is an acidic buffer (R1) containing the iron-binding dye Chromazurol B and ferric chloride. Some amount of...

I have calibration data and I'm want to use the following model: y = a + b*Ln(x)+ c*x I'm looking for a way to make initial guesses for the three paramaters a, b and c. Is there any way to linearize this expression so that I can use least squares analysis to determine values for a, b and c.

Thanks Bob S. I went to that site but I can't find anything that would help me derive expressions needed to make initial guesses for different models. Am I missing somethig perhaps?

Hi: This is my first post and I'm not sure if this is the right forum. Please redirect if necessary. I'm new to nonlinear regression, but from what I've read I realize that making "good" initial guesses for the model parameters is very important, otherwise a "best fit" may not result...