Linked Questions
39 questions linked to/from Funny behaviour when plotting a polynomial of high degree and large coefficients
9
votes
4
answers
792
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Numerical instability in cosh and sinh - integral functions [duplicate]
I'm trying to calculate the function:
CoshIntegral[x] Sinh[x] - Cosh[x] SinhIntegral[x]
Unfortunately Mathematica seems to hit a point (x~20) and things become ...
- 93
3
votes
1
answer
5k
views
How to increase precision: $MinPrecision does not help [duplicate]
I have the following series:
...
- 3,553
8
votes
1
answer
503
views
ReplaceAll[] and Limit[] don't give correct results for this expression under extreme variables [duplicate]
Possible Duplicate:
Funny behaviour when plotting a polynomial of high degree and large coefficients
1/x^2 + (3 + x)/(6 (1 - Exp[x] + x))
——This is a ...
- 63.8k
1
vote
1
answer
1k
views
Relative error plot [duplicate]
I was plotting the relative error of the $e^{11/12 -n}n^{n+1/2}$ approximation to $n!$ as $n$ gets larger and larger, and at some very large value of $n$ Mathematica gives this plot:
Can somebody ...
- 13
2
votes
1
answer
192
views
plot of polynomial expression failed [duplicate]
I want to plot a polynomial expression for {a,0,1}:
...
- 617
3
votes
1
answer
374
views
Dealing with square roots [duplicate]
Consider following expression:
$$
\sqrt{-\left(2 \sqrt{x^{-8/3}-x^{-4/3}+1}\, x^{4/3}+5\right) x^{4/3}+4 \sqrt{x^{-8/3}-x^{-4/3}+1}\, x^{4/3}+2 x^{8/3}+5}
$$
In code:
...
- 363
2
votes
1
answer
182
views
Strange behavior when replacing variables by numerical values [duplicate]
I have a rather complicated function with parameters {a, b, c, d, e, f, k}, and I'd like to know its behavior as a function of k alone given other parameters, so I try the following code:
...
- 754
0
votes
0
answers
94
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Why is PolyLog[] giving weird answers for ordinary values? [duplicate]
Possibly related to this question, but it seems slightly different:
Strange behaviour of PolyLog Function
Wikipedia says that for real s, z<1 should be real. So I was confused when MMa returned:
...
- 775
0
votes
0
answers
77
views
Matrix ODE gives badly-behaved numerical solution [duplicate]
I am trying to solve matrix ODE:
...
- 59
26
votes
6
answers
4k
views
Annoying display truncation of numerical results
I have a lot of data to inspect. An example of a number in my program is
123.189094
This gets displayed as
123.189
...
- 8,651
58
votes
3
answers
5k
views
Is manual adjustment of AccuracyGoal and PrecisionGoal useless?
This is a problem confusing me for years.
AccuracyGoal and PrecisionGoal are two options that I never truly understand and, to ...
- 63.8k
12
votes
4
answers
1k
views
Complex result for real vectors in VectorAngle
Bug introduced in 10.0 or earlier and fixed in 12.0.0 or earlier
I was expecting a real angle using VectorAngle when passing real valued vectors, but I obtained a ...
- 143
26
votes
2
answers
2k
views
Different floating-point numbers equal?
Let's define two different numbers.
x = 1.
y = 1. + 2^-52 (* equivalently, 1 + $MachineEpsilon *)
Let's make sure they're different with ...
- 7,801
9
votes
2
answers
3k
views
A problem about function N
Toady,I have a problem about N,described as below:
For example
N[1/3, 5]
(* ==> 0.33333*)
and ...
- 595
9
votes
3
answers
2k
views
Very different results from evaluating same expression with different precisions
When I evalute the following expression,
...
- 739