# Tagged Questions

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

62 views

### FunctionInterpolation produces many error messages when given high-precision input

Both FunctionInterpolation[1, {x, 0,1.00000000000000004}] and FunctionInterpolation[1.00000000000000004, {x, 0, 1}]; ...
430 views

### Permanently rounding numbers/values to a given number of significant figures

I am searching for a simple way of rounding and setting an input to a desired number of significant figures. There are a vast number of posts that discuss similar problems, but none address this ...
36 views

### Why doesn't N[0.33333, 3] return 0.333? [duplicate]

Basic question, other answers I found didn't really seem to address this. N[x,3] seems to only work if x is analytic instead of ...
29 views

### Analogue maple's Digits Environment Variable [duplicate]

I want setup (in Mathematica) once and for all operations number of digits after decimal point, similar how it's done in maxima: ...
81 views

### How can I completely discard decimals after a set number of significant figures?

I have a number with a long decimal tail, like x=1.23456789789456123 and I would like to (i) keep the first $n$ significant figures, and (ii) completely discard ...
170 views

### Multiply integrand with -1, and the precision changes?

"After multiplying the integrand of NIntegrate with -1, the Precision of the output will ...
25 views

### Passive Transformation does not return the expectedt result due to precision of expressions

So I wish to perform a passive rotation in N dimensional space. Let me take N=5 for this question. ...
111 views

### Mathematica Precisions vs Doubles in C/C++

I'm having a bit of an issue regarding numerical precision and I'm not sure how to deal with it. I have a certain randomly generated matrix, say $M$, that I wish to compute the eigenvalues. The ...
348 views

### How to calculate accurate answer in Mathematica?

I accidentally discovered for myself, that Mathematica outputs inaccurate answer. For instance, if I take $\sin(2 \cdot \pi \cdot 0.5) = 0$, then in Mathematica it is: But if I calculate it on ...
139 views

### Inaccurate Heliocentric coordinates of PlanetaryMoonData

I have noticed that the heliocentric coordinates obtained with PlanetaryMoonData are very inaccurate. Fore example, consider the Galilean moons of Jupiter: ...
58 views

### Precision in calculation [duplicate]

I am writing some code to demonstrate the effect of the number of significant figures a coefficient has on the solution of a nonlinear equation. I define the coefficient as follows: ...
189 views

### What's the proper way to 'cut out' an irrelevant part of an integral, so I don't run into problems with precision?

I'm doing a numerical integration that involves an integrand with a few exponentials whose values over the integration region range enormously. I'm really only interested in the part of the range that ...
45 views

### My NIntegrate expression returns a wildly inaccurate value

I am trying to integrate a function using NIntegrate: ...
56 views

### Artifacts in the solutions of NSolve [closed]

I have (what I think are) some problems with the precision of NSolve. I'm trying to solve this cubic equation: $a f^3(x)-b f^2(x)-c f(x)-z=0$ for the function $f(x)$ and then plot the following ...
42 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 ...
40 views

### How to preserve real number's precision

RealDigits[523.502] gives me {{5, 2, 3, 5, 0, 1, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9}, 3}. Is there a way in run time to tell ...
63 views

### WorkingPrecision and AccuracyGoal for using with NIntegrate

I'm modeling a quantum tunneling barrier. Because I want to express my quantities in mks units, that means that some of the variables I'm using are pretty small (10^-9). I use NIntegrate for part of ...
77 views

52 views

### Why won't something print with desired precision in a while loop?

I have a problem: when I ask something to print with precision P, that is, Print[N[something, P]], it does not print with precision P, just with the usual output precision. In particular, I have a ...
159 views

### Is it possible to change the precision in Compile?

I'm using Compile to do some numerical calculation and I need high Precision. I was wondering if it is possible to change the ...
92 views

### Is there any way to use compile and still maintain high precision in Mathematica? [duplicate]

Is there any way to use compile and still maintain Arbitrary-precision like 50 in Mathematica?
538 views

### more numerically accurate inverse matrix

I encountered the following matrix mat = {{2, 2.161209223472559 + 1.682941969615793 I}, {2.161209223472559 - 1.682941969615793 I, 2}} and ...
54 views

### Setting display precision in InputField with Dynamic variable

I have a following code: ...
1k views

### Replace very small numbers by zero in the output of a list

I have a long nested list, but many elements are numbers of order 10^-18 or less, e.g. ...
69 views

### CharacteristicPolynomial returns 0

I have a following matrix. ...
77 views

### $\tt PrecisionGoal$ and $\tt AccuracyGoal$ making the solution less accurate?

I am having this differential equation: ...
55 views

### Solve Numerical Equation [closed]

I want to find $x\in \ \mathbb{Q}$ such that the first ten digits of $x \pi$ are 1.234567890. I tried: ...
260 views

### NIntegrate fails to converge under almost any PrecisionGoal, MinRecursion etc. How can I trust the result?

I have been getting some ideas by reading other related questions in the forum, but the integral I have to do is not converging in many cases. The integrand is of the form: ...
57 views

### Workaround of non-integer indexed objects? [duplicate]

When using indexed object, I found the behavior of value 0.7 as the index quite strange, then did the following test. The first output cell was executed directly as the second input cell. Have not ...