David Carraher
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 Jan5 comment Table and memory efficiency Bracket missing in Table[Table[i*j,{i,1,10},{j,1,10}] Jan4 comment Real Numbers in the Wolfram Language Nice! I interpret your "distinct systems" to refer to disjoint classes. No number can be both an Integer and a Real data type. This flatly contradicts the mathematician's view of number classes. BTW, I was unfamiliar with \$Machine epsilon. It seems to be the smallest difference between two numbers. Reminds me of the following question I have posed to middle school students to provoke a discussion of continuity: "What's the smallest number that's greater than zero?" Lovely disagreements ensue. Apparently, computers can answer that question but mathematicians cannot. Jan4 revised Real Numbers in the Wolfram Language added 466 characters in body Jan4 comment Real Numbers in the Wolfram Language Mr.Wizard I often disregard chat links because the discussions often stray from the issue at hand. As I understand it, that's the very reason they were created: to move potentially distracting conversations to the sidelines. As for the question of answers in the form of comments, people sometimes leave code-less answers of substance among the comments in the belief that formal answers require at least some Mathematica code. Jan4 comment IntegerQ and Element Integers give different results in one case It is unfortunate that data types do not always correspond to number classes even though they may share the same name. See chat.stackexchange.com/rooms/19708/… for a discussion about data types versus classes of numbers (Real numbers). Jan1 comment “Unflattening” a list +1 This seems like a very straightforward approach that guarantees that the structure will be maintained. Dec28 revised How to Update 2D List based on a binary array minor improvements Dec28 comment How to Update 2D List based on a binary array +1 Very clever use of 1's and 0's. Dec28 revised How to Update 2D List based on a binary array added 18 characters in body Dec28 answered How to Update 2D List based on a binary array Dec27 comment How well does my function fit data? Antonio, Take a look at :reference.wolfram.com/language/tutorial/… and also reference.wolfram.com/language/ref/NonlinearModelFit.html "AdjustedRSquared" will tell you how much overlapping (shared or common variance) there is between your data and your model. It is a measure of goodness of fit. You can also obtain confidence intervals. Dec27 revised Plotting piecewise functions deleted 37 characters in body Dec27 answered Plotting piecewise functions Dec27 comment How well does my function fit data? Antonio, Modeling can tell us how closely the data fit the function, but it does not, and cannot, tell us "whether the function is correct or not". In that sense, models are approximations. Furthermore, there will inevitably be conditions under which the model "breaks down", i.e. ceases to provide a satisfactory description of at least some aspects of the phenomenon. Dec23 awarded Nice Question Dec22 revised Real Numbers in the Wolfram Language added 179 characters in body Dec22 revised Find Unconnected Subregions deleted 177 characters in body Dec22 revised Real Numbers in the Wolfram Language deleted 13 characters in body Dec22 revised Real Numbers in the Wolfram Language added 4 characters in body Dec22 revised Real Numbers in the Wolfram Language update