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Mar
20
comment Using Mathematica to confirm Bernoulli's inequality
@Dr.WolfgangHintze The inductive proof is standard material, but the question didn't ask for a standard proof. Instead, it wanted a Mathematica approach to confirming the relation. It's perhaps ambiguous what "confirming" means, but apparently my interpretation led to something that's clearer than the inductive proof.
Mar
20
reviewed Close ndode Input is not an ordinary differential equation error
Mar
20
comment Prevent evaluation of certain cells / code segments
Look at the Evaluatable in documentation Options for Cells
Mar
20
comment Efficient way to compute the gradient
Do you always have a regular grid? Do you want the magnitude of the gradient or a directional derivative? Do you want to avoid interpolation? How are the boundaries to be treated?
Mar
20
answered Using Mathematica to confirm Bernoulli's inequality
Mar
20
comment Using Mathematica to confirm Bernoulli's inequality
Reduce doesn't seem to be able to prove this. But one thing you have to change is the placement of the assumptions: they don't have any effect on Reduce the way you use them. See Inequalities with assumptions and constraints for the explanation.
Mar
19
reviewed Close How convert code from C# to Mathematica
Mar
19
comment Linear System with Complex Eigenvalues
Can you formulate a specific question? What is the Mathematica issue you want to address? It seems this is more a pedagogy question.
Mar
19
reviewed Close Problem with Replace function
Mar
19
reviewed Close NDSolve emitting dvnoarg error
Mar
19
comment NDSolve emitting dvnoarg error
Just get rid of the (v1^3).
Mar
19
comment Very slow mathematica finite differences
@shrx It's unnecessary here, but sometimes it can be useful because without it, While could remain unevaluated if the condition doesn't evaluate to True or False. This is among the "cosmetic changes" I mentioned.
Mar
19
revised Very slow mathematica finite differences
Added RuntimeOption
Mar
19
comment Very slow mathematica finite differences
@xzczd I forgot to add that - thanks! Of course, in reality FORTRAN is unbeatable for speed, but at least Compile gets reasonable speed.
Mar
19
answered Very slow mathematica finite differences
Mar
19
comment Very slow mathematica finite differences
Can't look at the details, but one thing jumps out in the first line: fGetNu gets re-compiled every single time it's invoked because it's defined with SetDelayed. Probably if you state the problem you want to solve, someone can come up with a better method using built-in functionality.
Mar
18
answered Recursion problem
Mar
18
comment I'm trying to use the following system of ODEs but it gives me some errors
You may have syntax errors. Make sure you enter all derivatives in an unambiguous way, because superscripts can be mis-interpreted. Never use variable names starting with capital letters, unless you know exactly what you're doing.
Mar
18
comment Simultaneously fitting two data sets to two functions is too slow
Your code doesn't run. It has errors in how the functions are defined. Without some example data, it's not possible to execute the fit.
Mar
18
comment How do I find local minimums in data?
Yes: FindPeaks[-data] would do that.