Toy Example #1: Fit exp decay curves

We read the both parameter tables and the data all from the same excel file. The data is a y(t) dependence containing several spans of exponential decay which we fit by non-linear least squares according to the formula a * exp(-(x-t₀)/τ), where t₀ is the span beginning and not fitted. The decay represents a capacitor discharge over a known resistor R. From τ, we get C, and by given area and ϵ we calculate the thickness of the capacitors dielectric.

We plot an overview plot of the data as well as plots of each span. The span start and end are the subset parameter from the table "params_experiment". The results are saved into two tables of an excel file: "SubsetsRslt" and "summary".

Location in GivEmXL project

"examples/RcExample"

User interaction

The user runs from from a terminal window a batch script rcex.sh / rcex.bat (invoking rcex.jl), to which he can optionally provide parameter -p / --plotformat, -e / --throwonerr, and -h / --help. These options are defined through the variable pp0::YAArguParser.ArgumentParser which is initialized in the file init_cli_options.jl. The user will be asked to point to "his" excel file with the parameters and data, and a GUI dialog opens. There are three excel files provided in the folder data/ of the example package. You may try it first with the file RcExampleData.xlsx.

Upon processing and saving the results, a corresponding message is printed, and either next file can be selected, or processing finished by typing -a / --abort. These interactions are defined by the variable pps, which is a NamedTuple of ArgumentParsers.

Processing functions

We define following functions in the file RcExample_specific.jl

• preproc: Reads the data into a DataFrame to be passed downstream, and produces the overview plot-
• procsubset: Does the fit on each span, and makes a plot.
• postproc: Applies DataFrames statistics to the results.

User invoked script

The rcex.jl has just one executable line (apart from the using statements). We have already discussed most of the parameters passed to the complete_interact function. getexel=true and getdata=(; dialogtype = :none) tell that there should be a GUI dialog for excel file only.

Error processing

There are two more excel files there: in MissingData.xlsx, some y values are missing in one of the spans, wheras in BrokenData.xlsx the expected data table is missing completely. In the first case, the data is processed as far as possible, and error information saved into the file named MissingData_err.txt, and in the second, only the file BrokenData_err.txt will be saved. If the flag --throwonerr was provided, the program would throw on the first error with the usual screenfull of information.

Development process

See file noninteractive_test.jl for how to supply the parameters to your processing functions in the course of the development process.