2,656 reputation
523
bio website
location United States
age
visits member for 3 years, 8 months
seen 6 hours ago

Started programming on a ZX spectrum in the 80's and have moved through Assembly, Turbo Pascal, C++, C#, Fortran. My main area of focus is engineering and scientific computing like numerical methods and 3D graphics.


6h
answered Can I convert between a rotation about an axis and a rotation according to two angles (all in 3D) without solving a system of nonlinear equations?
Jul
14
answered Find y-coordinate on a line between two (known) points
Jul
12
comment Question on Moment of inertia about center of mass of a smooth plane curve.
To prove mathematically one needs the shape functions for C and S. Otherwise you are left with common sense, which dictates that when $s\rightarrow \infty$ the center of mass and moment of inertia remain finite for S and become infinite for C.
Jul
12
comment Question on Moment of inertia about center of mass of a smooth plane curve.
Ok, I get it ${\rm d}I = \mu (x^2+y^2) {\rm d} s$ with $\mu=1$.
Jul
12
comment Question on Moment of inertia about center of mass of a smooth plane curve.
Yes mass you call it moment of inertia which is generally $\int \rho ( x^2 +y^2)\,{\rm d}x\,{\rm d}y$. Then don't call it like this if it is not.
Jul
12
comment Newton Rhapson Algorithm Accuracy
Until you run into machine precision and roundoff errors.
Jul
12
answered Finding the centre of mass and moment of inertia about a point of a laminate
Jul
12
comment Question on Moment of inertia about center of mass of a smooth plane curve.
The units make no sense to me. I think the integral needs to be over an area in order to produce ${\rm length}^4$ units.
Jul
2
awarded  Curious
Jul
2
comment Find intersections of two ellipses who share one fixed point
Can you add an example sketch?
Jun
12
answered Limit of $\sqrt{4x^2 + 3x} - 2x$ as $x \to \infty$
Jun
11
answered Disjoint conic sections?
Jun
9
comment Equation of a line in homogenous coordinates given 2 points in affine coordinates
Note $\times$ is the Vector cross product.
Jun
8
comment Simplify function with polynomial via least-squares
I agree that the poorly conditioned matrix will only be trouble when $N$ is high. I have used this for $N<100$ many times without any issue though.
Jun
8
answered Simplify function with polynomial via least-squares
Jun
4
comment Find the row echelon form of a 4x4 matrix
The end result is a row reduced matrix. The pre-multiply matrices represent the steps needed to get there. So if you pre-multiply the right hand side (which is missing from the post) with the same matrices you will end up with a row reduced system of equation.
Jun
4
answered Find the row echelon form of a 4x4 matrix
May
26
comment How to rotate a plane in 3-D using standard form?
That is the coordinate offset on the plane. The point on the N plane with planar coordinates $(0,0)$ has to map to a point $(u_0, v_0)$ on the M plane.
May
24
comment How to rotate a plane in 3-D using standard form?
Yes, $m_i = {\rm transform}(n_i)$
May
24
comment Solve Linear Sytem of Equation for $u,v,w$
This was just for illustrative purposes actually.