I have vector [ tex ] v [ /tex ] produced by an orthogonal projection of vector [ tex ] w [ /tex ] over plane spanned by vectors [ tex ] u_1 [ /tex ] and [ tex ] u_2 [ /tex ], in a three dimensional space. If I know [ tex ] v [ /tex ], [ tex ] u_1 [ /tex ] and [ tex ] u_2 [ /tex ], how could I...
Hi. I am trying to express the following in finite differences:
[ tex ] \frac{d}{x}\left[ A(x)\frac{d\, u(x)}{x} \right] [ /tex ]
If I take centered differences I get:
[ tex ] \left{ \frac{d}{x}\left[ A(x)\frac{d\, u(x)}{x} \right] \right}_i = \frac{[A(x)\frac{d\, u(x)}{x}]_{i+1/2} -...
Thanks xts. So, just to clarify, it's an ideal insulator; so if I ignore it I should never touch its initial value and I should use this initial value to update the neighboring nodes value. Is this right?
Hi. I don't know if this is the correct place to ask this, but prefer you to suggest me where I should ask. I'm starting with numerical simulation and I've been playing with the finite differences method to solve the heat equation on 1D, 2D and 3D uniform grids. This was really simple. Now I...
I was reading Turk and Pentland paper 'Eigenfaces for recognition' and they assert that, if M < N, the maximum rank of a covariance matrix is M - 1, being M the number of samples and NxN the size of the covariance matrix.
Is there any simple demonstration of this fact?
Thanks in advance...
Hi, I need to show this:
b_m \geq\sum_{i=1}^n b_i^2
given these three conditions:
b_m \geq b_i, for i=1..n (in other words b_m = max(b_i)) and
0 \leq b_i \leq 1 for i=1..n and
\sum_{i=1}^n b_i=1
I've been working for hours in this without results...Any clue would be really appreciated...
Hi,
I've this true/false statement: "If the electric potential is zero in some point of space, then the electric field in that point should be null"
I think this statement is false: the electric field might be generated for example by two charges: +5C and -4C separated by 2 meters. There...