563 views

### how to calculate with just double floating point precision [duplicate]

I want to calculate with simple double floating point precision. ...
305 views

### Exp of big negative numbers [duplicate]

I noticed that Exp have a strange behaviour with big negative numbers ...
• 42.9k
165 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: ...
• 35.5k
108 views

### Calculating eigensystem of a matrix containing very small numbers [duplicate]

I'm dealing with a matrix containing very small numbers like 10^(-370). When I compute the eigensystem of my matrix, it takes too much time, though the matrix size is not large. Can anyone explain ...
• 1,109
2k 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 ...
1k 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 ...
• 10.7k
1k 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: ...
• 1,389
467 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 ...
• 529
5k 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 ...
• 1,542
337 views

883 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 ...
• 58.4k
667 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. ...