Recent content by jimbo_durham

ps if anyone wants to see the results/method if they are doing anything similar, i can post them

solved. shell binning worked fine. alhough the volume of each shell was allowed to change, this was accounted for and the number density found as a function of radial distance from center, equating to a number density profile against actual velocity. thanks to anyone who read this and was...

Hi. I have a load of data objcts, each with velocity components in the cartesian x,y,z directions. I would like to find a measure of the distribution of velocity (assuming it is averaged in all directions - a good assumption). Ie i would like to end up with some 2d plot with velocity along the...

excelent, works like a dream. thanks sennyk

for example a point at (10,9,0) with magnitude 5 along the vector from the point to the origin as before, which is now (-10,-9,0). how do i find its components (vx, vy, vz=0)?

Hi, i have a known magnitude to give my vector in an xy plane, and i have a desired direction. I need the (vx, vy, vz=0) to describe my vector. I am sure this can be done easily. an example is, i have a point at (10,10,0) in cartesian (x,y,z) and will use this as the starting point of my...

perfect, this method is indeed correct. Thankyou D H

Thankyou. yes it is a function call to a routine which computes the sin/cos of the the three angles once before using that simple numerical values to calculate the rotations. I understand what you have said about the transpose of the rotation matrix being a transform martic which simply...

thanks for the quick reply. for my application this is a computational problem involving lots of objects, and i have a line of code changing my (x,y,z) into (x',y',z') using three euler angles (equivilent to a rotation matrix). this is easy to visualize, however i cannot easily visualize a...

I have a number of objects (points) in a 3D space. I need to rotate this space using euler angles (or equivilent) and place it in another coordinate system. (ie i start with objects placed within the confines of a cylinder aligned with the z axis, and after rotation have a cylinder of objects at...

note in formula, a, b, c are known constants

i am not sure how to apply that, i think it is worth me giving you the integral; \begin{equation} d_{M}=c_{1}\cdot sinh\left[c_{2}\int^{b}_{a}\left[\left(1+z\right)^{2}\cdot\left(1+c_{3}\cdot z\right)-z\cdot\left(2+z\right)\cdot c_{4}\right]^{-\frac{1}{2}}dz\right] \end{equation}...

I have a complicated integral which i need to compute numerically. I can do this in C++ using a version of Simpson's rule. I also need to compute the inverse of this integral (presumably this is what it is called) ie i have d=integral(f(x)dx) and i need to be able to compute x given a...