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Questions tagged [numerical-computing]

Is an interconnected combination of computer science and mathematics .

Is an interconnected combination of computer science and mathematics in which we develop and analyze algorithms for solving important problems in science, engineering, medicine, and business, for example, designing a bridge, choosing a stock portfolio, or detecting tumors in medical images

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Integration with variable limits

I need to evaluate a double integral where the inner upper Bound is variable: integral2 between -5 and 5 ( integral1 between 0 and y f(x)dx )dy. I'm stuck in the calculation of the outer loop which is dependent on the inner loop. My code runs for a…
user8907108
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A Numerical Computing Library for C

I’m looking for a good numerical computing library for C programming language. Similar to LAPACK with good documentation would be very helpful. Thanks & Regards, Upul
Upul Bandara
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QR Householder factorization of banded matrix

I have banded matrices with lower band kl and upper band ku. I want to put them in lower triangular form and to do so, I am employing QR Householder. So, I modified the QR Householder algorithm for the lower band but can't get to a modification of…
Math Stout
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Why combination of backward FFT(c2r) and forward real-input FFT (r2c) to one complex array doesn't result original complex array?

Real-input FFT is usually expressed rfft and inverse is irfft in many programming languages (like python or julia). As numpy docs or julia docs said, they are doing normalized FFT not like FFTW's unnormalization FFT Hence, if I have real input 1D…
Jongsu Liam Kim
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How to use standard SimpsonIntegrator in import org.apache.commons.math3.analysis.integration.SimpsonIntegrator;

public double evalute(double distance){ /** * equation (3.2) */ this.from = 0; this.to = distance; this.n = 2; return - 10 * Math.log10(Math.exp(-IntSimpson(this.from, this.to, this.n))); } There is IntSimpson()…
Alex Titov
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Using transformation matrices in Python - numerical precision errors

So no need to see all the code but basically I have an initial point: import numpy as np point = np.array([3.0000, 8.0000, 0.0000]) I also have a transformation matrix M which works fine that needs to transform the point into the X-axis only, this…
Hadi Farah
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Forward Difference table with c++ using Dynamic Array

i have created forward difference table by using static array but can't solve it by using dynamic array please help me to solve this table. This is the code with static array but i need it with dynamic array #include int main() { …
Saqib Mehmood
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Acceleration to Displacement

I'm doing an experimental program. I've a smartphone fixed on the car dashboard with a support, during the travel I read from an application some value from inertial sensor. Precisely I read, Accelerometer Data Time (at fixed interval) of each…
traveller
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Forward-Euler Method

I'm doing an experimental program. I need to find elevation from a set of experimental data. I record only time and acceleration data and I used Forward Euler Method to solve the double integration. The code that I wrote is this. public void…
traveller
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Romberg Integration algorithm

I want to solve a basic integral over a given interval [a,b], for an arbitrary n and m values in R(n,m) with Romberg integration. I have derived Boole's rule from the Trapezoid Rule, so I know how to do this on paper. I've even drawn a flow chart…
rocksNwaves
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How to output 2 or more arrays in a fortran's function?

I am writing a program which computes the LU decomposition of a matrix, with partial pivoting, and I would like the function to output several (2 or 3) matrices without running the program several times to output each one individually, which is a…
António Carneiro
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adding bounds to code, matlab

I am trying to add bounds to the code but having troubling figuring out where to put them. The equation goes: f(x) = e^(6x) + 1.441e^(2x) − 2.079e^(4x) − 0.333 = 0, -1>=x<=0 function c = newton(x0, delta) c = x0; fc = f(x0); …
Stan-Lee
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Finding centre line of a pipe using python

I am currently writing a code in Python for flows through pipes. In this regard, I have to find a centre line passing thorough a 3D pipe geometry defined by a nastran mesh (cells with three or four edges whose coordinates i can access). I am using…
outofplace
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Pressure-Impulse-at-One-End, Wave Equation

I am trying to solve the captioned problem numerically using Mathematica, to no avail. Imagine a rod of length L. The speed of sound in the rod is c. A pressure impulse of gaussian shape whose width is comparable to L/c is applied at one end. I…
Jamie
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Controlling order of operations in C code

I read that Fortran has strict rules on the order in which expressions are evaluated. For some numerical algorithm, this is very important. How do numerical C programs control the order of floating point operations and prevent the compiler from…
user782220
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