# All Questions

9,961 questions
Filter by
Sorted by
Tagged with
293 views

### changing from global to local coordinate structure

I am going to put this question on math exchange and stack exchange as well (since it doesn't really fit in any of the specific fields, I don't know which it should go in), but here is the question: ...
192 views

### High-resolution finite volume schemes for two phase flow (fields with jumps) literature sources

what other recent sources of literature on this topic would you recommend? This is where I'm starting from: Leveque's article: HRIC scheme But the related articles seem to be a bit dated (some up ...
21k views

### How to set double precision values in Fortran

Recently, I've encountered a bizarre problem with FORTRAN95. I initialized variables X and Y as follows: X=1.0 Y=0.1 Later I add them together and print the ...
227 views

### Will upgrading to a 64 bit OS help me any?

Assuming that I am running Intel MKL (BLAS, LAPACK), is there any difference in performance if I run it on a 32 or 64 bit OS? (Of course, assuming that my hardware remains the same). My processor is ...
525 views

### Polynomial Regression using Semidefinite Programming

I'm trying to design the frequency response function for a low-pass filter. I need the function to be polynomial and to fulfill the following constraints: the coefficients must sum to 1, the function ...
262 views

### Condition number of (A + cI) matrix

For given matrix $A \in R^{n\times n}$, identity matrix $I$ and constant $c > 0$ is this possible to express $cond(A + cI)$ knowing $cond(A)$ and $c$?
61 views

### Can PetscBags be used with 64 bit versions of petsc?

I was looking at the documentation for PetscBagCreate(), and it says that The size of the A struct must be small enough to fit in a PetscInt; by default ...
746 views

### Modern Computer Efficiency vs Modern Nervous Systems

I am currently working on an evolutionary system and most of what I have heard is that a computer like mine at the moment would be able to simulate a bee sized brain (not taking into account the time ...
1k views

### Solve log equations problem [SageMath]

Input var('x') solve((log((x**2 - x), 6) - log((6*x - 10), 6) == 0), x) Output [log(x^2 - x) == log(6*x - 10)] But real ...
1k views

613 views

### Runge-Kutta and Reusing Datapoints

I am trying to implement the fourth order Runge-Kutta method for solving a first order ODE in Python i.e. $\frac{dy}{dx} = f(x,y)$. I understand how the method works, but am trying to write an ...