I need to plot some raw data (experimental) and a function representing a model on the same set of axes in order to compare accuracy of the model relative to the experimental data. I am able to plot each one on separate axes without any problem, however when I try to add the vector containing the raw data to the y axis of a plot of the function, I get an error that states "the value must be real".
Please advise on how to resolve this.
Without your worksheet it's hard to guess exactly what goes wrong.
You should either make sure to evaluate your function on each of the experimental (x-axis) points, or use a separate running variable for plotting the function:
Above is the separate running variable. Below uses the x-data points from the data table:
If you use a new entry on the y-axis it needs a corresponding entry on the x-axis. If ther is none, the last one on the x-axis is used instead.
So from your description I guess you have a function lile f(x) and a vector od y-data values on your y axis. That way you would need an independent variable x (either use quickplot or define x as range) AND a vector of x data values on your x-axis.
An alternative, which was also shown above, is to use only the data value on the x axis, lets say its X, and use Y and f(X) (eventually you need to vectorize that call) on the y axis. You will lose the intermediate values of your function that way, though,as it sill aonly be evaluated at your data points.
BTW, it would have been a good idea if you had attached your worksheet so we would not have to guess what exactly you did wrong.