Linked Questions

23
votes
4answers
799 views

SetOptions locally?

Is there a way to SetOptions locally? For example, I have a Module and inside it I am doing a lot of ...
22
votes
2answers
454 views

Plotting a defined function gives different results from plotting the function directly

Consider the following piece of code: function[t_]:=Exp[-9 t^2]; LogLogPlot[{function[t],Exp[-9 t^2]},{t,.01,100}] I expect the two plots to exactly overlap each ...
17
votes
2answers
285 views

CompiledFunction returns machine numbers smaller than $MinMachineNumber

When thinking on the workaround for this LogLogPlot bug suggested by halirutan I noticed that CompiledFunction actually can ...
15
votes
8answers
1k views

Product of elements of a list

Sum is for functions; Total is for a list. Product is for a function; what is the command ...
12
votes
5answers
827 views

NDSolve DAE with Constraints

I'm trying to make some numerical simulation with NDSolve. I have encountered a few problems. Here is a simplified version of the equations: ...
12
votes
1answer
753 views

Why does 1 - Exp[-10.0^12] cause an out-of-memory error?

I would like to understand why evaluation of the expression 1 - Exp[-10.0^12] causes an out-of-memory error and how can I prevent such errors when calculating ...
8
votes
3answers
4k views

Machine precision near zero: not fulfilled?

I am puzzled by the behavior of Mathematica machine precision with numbers approaching zero. This manifests itself, e.g., with FixedPoint and the like. In the ...
8
votes
1answer
681 views

DSolve with SetOptions[Solve, Method -> Reduce] Behaving Differently in Ver 11.1.1

With version "11.1.1 for Microsoft Windows (64-bit) (April 18, 2017)", DSolve[{SI'[s] == Sin[PH[s]] , PH'[s] == Sin[SI[s]]/e}, {SI[s], PH[s]}, s] produces the ...
8
votes
1answer
249 views

Exp of big negative numbers [duplicate]

I noticed that Exp have a strange behaviour with big negative numbers ...
7
votes
1answer
185 views

Change system options in package

I use Mathematica mostly for numerical calculations, and sometimes the performance of numerical calculations can be greatly improved if the high-precision arithmetic can be switched off by ...
6
votes
0answers
137 views

Can I force Mathematica to use machine precision? [duplicate]

Some built-in functions (like Exp) give an arbitrary precision result, even when the argument is a machine precision number. Example: ...
5
votes
2answers
402 views

Underflow error General::munfl from E^x instead of Exp[x]

In contrast to earlier versions, Mathematica 11.3 and 12.0 generate lots of underflow errors from my code, e.g. ...
5
votes
1answer
305 views

Slow exponential evaluation over lists

This question,which is still unanswered, might be relevant because it involves NIntegrate over lists and it also has Exp. In ...
5
votes
2answers
356 views

Optimizing code containing an infinite sum

I have the following expression. It's based on the negative-log-likelihood of a Poisson-Gaussian noise model, i.e. a convolution of a Poisson & Normal distribution. The value $x_{i}$ is the ...
4
votes
3answers
613 views

Why does DSolve return two solutions for my ODE?

I wanted to solve the differential equation: $y’ = (1+2x)\sqrt{y}$ with $y(0) = 1$. It can be done by hand, and to check my answer I typed the following in Mathematica ...

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