Questions dealing with the relative uncertainty in the values computed, stored, or manipulated by Mathematica.

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17
votes
0answers
231 views

Is MathieuC for moderately large imaginary arguments broken?

I'm trying to plot MathieuC[-3,0.3,I x] for $x\in[0,10]$, and here's what I get even with arbitrary precision arithmetic (here I use ...
6
votes
0answers
128 views

Why has Version 10.3 precision reduced?

In version 7.0.1.0 and versions 10.0 and 10.1 the following is produced: ...
5
votes
0answers
91 views

Is there a problem with some of the curated Star Data?

I'm not really sure if I'm doing something wrong, or if there's a problem with some of the Mathematica curated data on stars. My problem is this: I'm trying to find the location (latitude and ...
5
votes
0answers
64 views

The change of precision doesn't work in ParallelDo. Is it a bug in Parallel?

Cross-post: http://zhidao.baidu.com/question/2075301703219376588.html Input: ...
4
votes
0answers
356 views

Precision and accuracy in NDSolve and NMinimize

I use NDSolve quite a lot and have noticed that setting values for AccuracyGoal and ...
4
votes
0answers
124 views

Precision problem while evaluating RegionMember or Element in V10

I'll try to give you a background on where the problem occured. The problem itself is defined near the end of the post. I'm running a sort of a simulation of a particle in a box. I finally got my ...
4
votes
0answers
138 views

Tools for Stability/Automatic Error Analysis in Mathematica

I have a longer analytic expression in several variables containing special functions and others. Does Mathematica bring tools - or are there any packages - to examine the stability when I evaluate ...
3
votes
0answers
131 views

Is FindRoot wrong about its WorkingPrecision?

I noticed an odd mismatch between the behaviors of NDSolve and FindRoot. If you give NDSolve an equation of a certain precision, say 20, and tell it to use a higher WorkingPrecision, say 30, it will ...
2
votes
0answers
61 views

Precision loss in FourierDCT

I have high precision data that I want to do Fourier transform with, but it looks like the precision is lost dramatically. ...
1
vote
0answers
40 views

Numerical Integral with Boolean as part of argument

I am trying to numerically calculate a partial surface area integral of an oblate spheroid in spherical coordinates. The area I want to calculate is determined by a boolean function in the argument of ...
1
vote
0answers
75 views
1
vote
0answers
71 views

Problem with calculating Harmonic Numbers

I have tried to take a series of Harmonic Numbers using mathematica but there have been issues in calculations. So far when I computed the sums at a small value range such as ...
1
vote
0answers
71 views

Odd plotting/math issue (could be a precision problem)

I've got a pretty odd error on a project I'm working on and was hoping to enlist some advice to fix it. The goal of this notebook is to show that I can eliminate the non-normalizable (blowing up part) ...
1
vote
0answers
141 views

How to control precision of parameters in NonlinearModelFit?

I am using NonlinearModelFit for fitting a dataset to some complex numerical model function that depends on a few parameters. The final required precision of these parameters is very low, like 3 ...
1
vote
0answers
50 views

Which operations preserve digit precision?

Imagine I had to use numbers with a 600 precision digits. Do all mathematical operations, like +,-,...
1
vote
0answers
140 views

the default option of NDSolve

How should I find out what the default value of Accuracy and Precision is in the NDSolve? I have a pde that when I asked it to solve for me the equation with a special Accuracy and precision it gave ...
1
vote
0answers
65 views

Precision of sliders in WebMathemtica

I have been developing a manipulate plot to put on the web. One of my parameters varies over a small interval, {{D32, 2.38*10^-3, "D32"}, 0.001227, 0.0049108}. This ...
1
vote
0answers
30 views

Ignore $MinPrecision when using Print

I have a function that contains a For loop and sometimes takes several hours to run. It's important that I keep a high precision, and I insert ...
0
votes
0answers
93 views

Why do Precision and Accuracy level off in this calculation?

I am confused by this behavior, where Precision and Accuracy seem to reach a bottom and deteriorate no further as I perform more iterations on this calculation. Have I misunderstood something about ...
0
votes
0answers
38 views

Maintaining working precision in my program

I am badly stuck with this program I am writing. I want output of program below to be precise up to 25 digits after decimal point. I am supplying all inputs with precision 25. But after each iteration ...
0
votes
0answers
67 views

CharacteristicPolynomial returns 0

I have a following matrix. ...
0
votes
0answers
47 views

Why does Save change my data precision?

I have some data from some Mathematica program, and it appears that the precision of the data has been slightly changes when I save the data and reload it again. ...
0
votes
0answers
109 views

universal precision control in Mathematica

There are many ways to control precision in Mathematica, such as PrecisionGoal in specific build-in commmands or SetPrecision to some variables. I got two questions below, (1) If I do not set any ...