I replied to Michael privately but am intrigued by his words here: "The thing that creates realistic test cases is my brain."
I consider extensions to my brain to include using a language like Python on my computer and in particular, to take a model I think of and instantiate it. Lots of people have shared modules that can be tweaked to do all kinds of simulations using a skeleton you provide that guides random number usage. Some will generate lots of those and stare at them and use their brain to further narrow it down to realistic ones. For example, in designing say a car with characteristics like miles per gallon should randomly range between 10 and 100 while engine size ranges from this to that and so on, it may turn out that large engines don't go well with large number for miles per gallon. I have worked on projects where a set of guides then created hundreds of thousands of fairly realistic scenarios using every combination of an assortment of categorical variables and the rest of the program sliced and diced the results and did all kinds of statistical calculations and then generated all kinds of graphs. There was no real data but there was a generator that was based on the kinds of distributions previously published in the field that helped guide parameters to be somewhat realistic. In your case, I understand you will decide how to do it and just note you used language with multiple meanings that misled a few of us into thinking you either had a python function in mind using one of several ways Python refers to as generators, such as one that efficiently yields the next prime number when asked. Clearly your explanation now shows you plan on making a handful of data sets by hand using an editor like vi. Fair enough. No need to write complex software if your mind is easily able to just make half a dozen variations in files. And, frankly, not sure why you need XML or much of anything. It obviously depends on how much you are working with and how variable. For simpler things, you can hard-code your data structure directly into your program, run an analysis, change the variables to your second simulation and repeat. I am afraid that I, like a few others here, assumed a more abstract and much more complex need to be addressed. Yours may be complex in other parts but may need nothing much for the part we are talking about. It sounds like you do want something easier to create while editing. -----Original Message----- From: Python-list <python-list-bounces+avigross=verizon....@python.org> On Behalf Of Michael F. Stemper Sent: Tuesday, September 28, 2021 11:38 AM To: python-list@python.org Subject: Re: XML Considered Harmful On 27/09/2021 20.01, Avi Gross wrote: > Michael, > > Given your further explanation, indeed reading varying numbers of > points in using a CSV is not valid, albeit someone might just make N > columns (maybe a few more than 7) to handle a hopefully worst case. > Definitely it makes more sense to read in a list or other data structure. > > You keep talking about generators, though. If the generators are > outside of your program, then yes, you need to read in whatever they produce. My original post (which is as the snows of yesteryear) made explicit the fact that when I refer to a generator, I'm talking about something made from tons of iron and copper that is oil-filled and rotates at 1800 rpm. (In most of the world other than North America, they rotate at 1500 rpm.) Nothing to do with the similarly-named python construct. Sorry for the ambiguity. > But if > your data generator is within your own program, The data is created in my mind, and approximates typical physical characteristics of real generators. > My impression is you may not be using your set of data points for any > other purposes except when ready to draw a spline. Nope, the points give a piecewise-linear curve, and values between two consecutive points are found by linear interpolation. It's industry standard practice. > Can I just ask if by a generator, you do NOT mean the more typical use > of "generator" as used in python Nope; I mean something that weighs 500 tons and rotates, producing electrical energy. > Do you mean something that creates > realistic test cases to simulate a real-word scenario? The thing that creates realistic test cases is my brain. > These often can > create everything at once and often based on random numbers. I have written such, but not in the last thirty years. At that time, I needed to make up data for fifty or one hundred generators, along with tie lines and loads. What I'm working on now only needs a handful of generators at a time; just enough to test my hypothesis. (Theoretically, I could get by with two, but that offends my engineering sensibilities.) > create everything at once and often based on random numbers. Again, if > you have or build such code, it is not clear it needs to be written to > disk and then read back. Well, I could continue to hard-code the data into one of the test programs, but that would mean that every time that I wanted to look at a different scenario, I'd need to modify a program. And when I discover anomalous behavior, I'd need to copy the hard-coded data into another program. Having the data in a separate file means that I can provide a function to read that file and return a list of generators (or fuels) to a program. Multiple test cases are then just multiple files, all of which are available to multiple programs. > You may of course want to save it, perhaps as a log, to show what > your program was working on. That's another benefit of having the data in external files. -- Michael F. Stemper A preposition is something you should never end a sentence with. -- https://mail.python.org/mailman/listinfo/python-list -- https://mail.python.org/mailman/listinfo/python-list
