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Sep
12
revised Plot electric potential and field
Suppress infernal warnings from abysmal AbsoluteOptions in version 10.
Sep
12
comment Solve Laplace equation using NDSolve
@SantiCarmesí For the gradient and field strength, you can use my answer here. The error message in the potential plot appears because the inner boundary isn't sampled quite accurately. One can get rid of this by first defining rm=RegionMember[\[CapitalOmega]] and then replacing the plot argument sol[x,y] by If[rm[{x,y}],sol[x,y],100].
Sep
12
answered What is the equation to plot a vertical line?
Sep
12
comment How to get an Excel-like surface plot with ListContourPlot3D
Isn't "Excel" - "like" a contradiction in terms?
Sep
12
reviewed Close Getting message NIntegrate::inumr: in V10; did not happen in V9
Sep
12
reviewed Close How to use many global assumptions
Sep
11
revised Is there a built-in function which detects singularities in a function?
Another example added
Sep
11
comment Is there a built-in function which detects singularities in a function?
@Artes I agree on the closeness because the intention here was originally to find points of non-differentiability, too. But I interpreted the usage of "singularity" here to be more general. E.g., Abs[x]^2 would be differentiable but still singular.
Sep
11
comment Is there a built-in function which detects singularities in a function?
Clearly FunctionDomain can yield True for non-analytic functions, such as the third one (or anything with singularities in higher derivatives). But it does detect the Tan singularities (as does my answer).
Sep
11
comment Is there a built-in function which detects singularities in a function?
@Dr.WolfgangHintze I added the arbitrary c because I can't specify a numerical expansion center, since that may happen to be a special point of singularity. E.g., 1/x can't be expanded around 0, but it can be expanded around c. So I avoid unnecessary error messaged this way. Maybe this could be eliminated if instead I catch such errors differently...
Sep
11
reviewed Close ListLinePlot of data imported from an Excel file
Sep
11
reviewed Close No values in plot
Sep
11
comment Is there a built-in function which detects singularities in a function?
@Szabolcs That's true - it may even be part of the symbolic processing step. For example, if I define ff[x_?NumericQ] := Sign[x] then Plot[ff[x], {x, -1, 1}, ExclusionsStyle -> Red] doesn't show any detected exclusions.
Sep
10
revised How to assign up-values for `Derivative`?
Changed derivative definition for arb. orders
Sep
10
comment How to assign up-values for `Derivative`?
I'm not exactly sure I understood your question (though I answered already)... If you're just worried why the Series didn't simplify with your definition for D, then it's because you didn't define ln for symbolic a. That's why I used a numeric a in my answer in the series.
Sep
10
answered How to assign up-values for `Derivative`?
Sep
10
revised Is there a built-in function which detects singularities in a function?
analyticity test added
Sep
10
revised Is there a built-in function which detects singularities in a function?
added 137 characters in body
Sep
10
answered Is there a built-in function which detects singularities in a function?
Sep
10
comment Is there a built-in function which detects singularities in a function?
Are a and b always real? Are the parameters in the functions symbolic, or are they all numerical? I assume a in g[x] isn't the same as the interval boundary a? I.e., are you looking for numerical or symbolic solutions?