Output format of lsqnonlin objective function

Hello All,

I have a chemical model to optimize (using LSQNONLIN). This model must work in different temperatures. For each temperature, I have three different data sets (Excel sheets). So, the optimization program must read all the data sets for each temperature. However, differential equation solving (ODE) must be done for each excel sheet separately.

So, what I have designed is as follows:

The optimization program solves the differential equation(ODE) for one excel sheet.

Write the result in a vector.

It again solves the ODE for the next excel sheet.

Adds the data to the previous vector.

This process is done until all excel sheets (3 excel sheets) are read.

This vector is the output of the objective function of LSQNONLIN.

I am wondering if this process is correct or not.

I have also another question.

When I run the optimization program for one excel sheet, in some cases the result is converging, while it doesn't converge for some others. Does it show that the initial guess is incorrect for the second case (and the main model and objective function of LSQNONLIN is correct)?

Thanks in advance