# precision's questions - English 1answer

273 precision questions.

### 4 How to force precision in region plots containing Erfc

2 answers, 137 views plotting numerics precision
I'm trying to use regionplot for functions that involve Erfc. A slightly contrived example follows, but it illustrates my difficulties. The command ...

### 1 How can I improve the numerical results while working Mathematica

2 answers, 50 views equation-solving numerics precision
I'm trying to solve nonlinear equations using Newton-type methods with very high accuracy using Mathematica. I found many research papers in which the numerical results are calculated with very high ...

### 1 Numerical error in compile, Strange behaviour in numerical evaluation

First of all, apologies for the large numbers, I couldn't find a working example for a far lower order and the zeros are necessary... my problem is this: I have a large polynomial (from high-order ...

### 8 Contour integration, residues and precision of the poles

1 answers, 124 views calculus-and-analysis complex precision
Task I am trying to evaluate the contour integral of some functions. To have a concrete example, let's use $$f(z,s) = \frac{1+(4+2s)\, z}{z - \left( 9 + 35s + 24s^2 + 4s^3 \right) z^2 + 8z^3}$$<...

### 5 How to get accurate solutions from FindRoot?

2 answers, 233 views equation-solving precision

### 5 What is a sufficient decrease in the merit function?

1 answers, 233 views equation-solving error precision
As far as I understand, the merit function measures how far the data is from the fitted function. I am calulcating the second partial derivative of a function, and then numerically finding its maxima ...

### 5 Precision loss in FourierDCT

2 answers, 187 views fourier-analysis precision
I have high precision data that I want to do Fourier transform with, but it looks like the precision is lost dramatically. ...

### Precision issue using functions

1 answers, 28 views functions precision
I just want to get a smooth plot but the calculated values are "discrete" which seems to be a precision problem. I tried N[],SetPrecision[],SetAccuary[] without any success. So I paste the Code in its ...

### Iterative calculation of a number-theoretical constant [closed]

2 answers, 115 views precision number-theory
Recently the decimal expansion of a number theoretic constant was searched for, which is the analog of the Landau-Ramanujan constant in a certain context. The constant starts 0.638909... It can be ...

### Interpolation is not smooth

Consider a function ...

### 1 Printing out reals in a table with a specified number of digits

I would like to print out an list of reals in a table with perfectly identical number of digits so that they can be perfectly right-aligned. However, once I convert them to strings, ...

### 1 Plotting with small variations along the vertical axis

3 answers, 64 views plotting precision
I can't see the small changes of my function when I plot it. What can I do? ...

### 3 digits of NDSolveValue

I am solving PDE by means of NDSolve and I am interested in a highly accurate value for the solution at a certain point. For some reason, the solution obtained by ...

### High precision NDSolve

0 answers, 42 views differential-equations precision
I need to solve an ODE with very high precision. I am not sure yet how much precision I need so I have some question before changing the settings. From what I understand, the working precision is how ...

### 2 How to avoid problems with the large imaginary part of LegendreQ?

I am trying to evaluate sums involving LegendreQ[n,x], the n-th order Legendre function of the second kind $Q_n(x)$, at large $x>1$. However, the problem is that ...

### 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 ...

### 4 Mathematica precision common problems

1 answers, 121 views precision arbitrary-precision accuracy
When I do something a little bit more complicated than standard documentation examples, I often hit precision problem. Or I accidentally disprove Riemann hypothesis Like this ...

### 5 Is FindRoot wrong about its WorkingPrecision?

2 answers, 500 views equation-solving precision
EDIT: I filed a bug report and after a small back-and-forth the support person agreed this is a bug. He said: "I have filed a report with the developers to issue warning messages when the arithmetic ...

### 7 How to round half down in Mathematica?

2 answers, 348 views numerics precision
I found this and this on this StackExchange as to why Mathematica rounds half to even, which means thatRound[{0.5, 1.5, 2.5, 3.5, 4.5}]gives ...

### 1 Precision Issue with Log

1 answers, 45 views precision machine-precision
I have the following codes. Naturally, I expect to get zero. I thought it is due to some possible issues stated as "Machine-precision inputs can give numerically wrong answers on branch cuts:". ...

### 60 When can I assume that all decimal digits returned by Mathematica are provably correct?

How to Control the Precision and Accuracy of Numerical Results Arbitrary-Precision Numbers Mathematica works with exact numbers and with two different types of approximate numbers: machine-...

### how to avoid set precision for the components of an array? [duplicate]

I have an array a with 9 components and when i set precision for this array, components of a also get the precision.however, i want to avoid that and only the number get the precision. for instance, a[...

### 37 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 ...

### 6 Is it possible to generate a message when precision upgrade occur?

I use Mathematica mostly for numerical simulation, so most of the time double precision (or machine precision) is enough for me. Mathematica has this nice feature of automatically upgrade to arbitrary ...

### 29 Why does Mathematica results differ from C++ results within machine precision?

2 answers, 3.668 views precision machine-precision c++
I am trying to wrap my head around floating-point precision. Performing the following numeric operation:275./6.*1.03692775514337in Mathematica and C++ and ...

### NIntegrate, how exact is the answer?

Since the precision is very important in my case, I am curious how precise is the MMA result for this integral: ...

### 3 PlotRange label digit precision

2 answers, 178 views plotting precision style
I'm trying to plot a set of points, Mathematica create the plot with the right range but it doesn't show all the digits (only shows up to six digits): ...

### 8 Strategies to solve an oscillatory integrand only known numerically

3 answers, 4.386 views numerical-integration precision
I have an integrand that looks like this: the details of computation are complicated but I only know the integrand numerically (I use NDSolve to solve second order ...