Mathematica

test implication
hello mathematica community, knowing tha x,xP,y,yP are integer variables so y + Log[2, x] == yP + Log[2, xP] ==> y + Floor[Log[2, x]] == yP + Floor [Log[2, xP]] is true how should I formulate this sentence in mathematica in order to have as output the value true? thank you. ... 27 Nov 2009 07:43

countour plot (in 3D)
Hi, I have a set of 720 measurements at locations (x,y,z), each associated with a value (f). The y is constant for all locations. So I can generate a ListContourPlot quite easily and nicely. Now I want to show the contour in 3D. This means essentially I want to show a contoured plane in 3D. I want to do th... 30 Nov 2009 06:57

Is it possible to make NIntegrate
Oh well. I've seen cases where separating the branches WAS worthwhile, but it's not surprising to find cases where it isn't. The dissected version might be more readable in some situations, too. Bobby On Wed, 25 Nov 2009 01:31:29 -0600, Leo Alekseyev <dnquark(a)gmail.com> wrote: Apologies for missing ... 25 Nov 2009 23:55

When Wolfram's technical support cannot help
Hi I sent this email to technical support (as I hold a premier licence) I am looking for a single function that will extract the cyclic part of (a) a completely cyclic sequence and (b) an eventually cyclic sequence. So if data1={1,2,3,1,2,3,1,2,3,1,2,3} then cyclicpart[data1] should return {1,2,3} And if ... 26 Nov 2009 01:00

problem about calling Mathematica in Fortran
Hi all, I have written a C program to call FindFit succesfully, then I want to use it in a Fortran project. I have called the C function in Fortran program, and the compilation is ok with linking libML64i3.so. But when running the executable, it said the connection with MathLink failed. What is the problem? Any ... 25 Nov 2009 07:03

problem about calling Mathematica in Fortran
���� �: Hi all, I have written a C program to call FindFit succesfully, then I want to use it in a Fortran project. I have called the C function in Fortran program, and the compilation is ok with linking libML64i3.so. But when running the executable, it said the connection with MathLink failed. W... 25 Nov 2009 07:03

Help with algorithm to find rational roots of a bivariate
TPiezas wrote: Hello all, Does anyone know an efficient algorithm using Mathematica that can find _rational_ roots of a non-homogenous eqn in two variables with deg > 4? For ex, you want to find rational {x,y} such that, F(x,y) = x^n + (P_1)x^(n-1) + (P_2)x^(n-2) + .... = 0 where the P_i ... 24 Nov 2009 06:40

how to find a function
Dear Math Group:- Suppose we have:- x = a * e + (2*b - 3*a^2) * e^2 Now let us find such functions: F(x) = 1 + a * e + (2 * b - a^2) * e^2 + ...... we are just interested in the first three terms. Now two such functions can be: F1(x) = 1 + x + 2 * x^2 and F2(x) = (1-x)/(1-2*x) How can we... 25 Nov 2009 02:42

Bug in Plot3D?
The two plot commands in the notebook below should give identical outputs, but they don't. The notebook is posted at http://abstractmath.org/MM/MmaBugQ.nb a := 9; b := 18; ff[x_, y_, z_] := x + y + z gg[x_, y_, z_] := 2*x - 2*y - z f[x_, y_] := z /. Solve[ff[x, y, z] == a, z] f[x, y] g[x_, y_] := z ... 25 Nov 2009 02:42

Solving systems of differential equations
I have a question as to an apparent inconsistency I noticed while using Mathematica to solve differential equations, I have 2 ODE like this, and I solve them symbolically using Mathematica 7.0: system = {p'[t] == -(rho + d)*p[t], n'[t] == rho*p[t] + (rho - d)*n[t]}; sol = DSolve[system, {p, n}, t][[1]] I get ... 25 Nov 2009 02:42