Recent content by LMHmedchem

I do have this working now using the Eigen library and it is pretty fast. Let me know if anyone would like the c++ code posted. I think I am still unsure about calculating the distance between P and pi, P and B, and pi and B. Normally I would just take the vector between each pair of points and...

Hello Again, If I have point B in an orthogonal n-space and point C at the origin of the same space, point_B = 0.03299720 0.00585822 -0.36979000 -0.43413200 -0.60787700 0.61335300 0.76003400 point_C = 0.00000000 0.00000000 0.00000000 0.00000000 0.00000000 0.00000000 0.00000000...

I forgot to transpose the three vectors v1, v2, and v when I made M. Thanks, LMHmedchem

I have been trying to code this up with the Eigen library but I seem to be misunderstanding the order of operations. This expression, $$ (M^TM)^{-1}M^T \mathbf v_3% $$ seems to involve either the product, $$ ( (M^TM)^{-1}*M^T )* \mathbf v_3% $$ or the product, $$ (M^TM)^{-1}*(M^T* \mathbf v_3)%...

So Octave will automatically evaluate M \ v3' with an inverse, pseudo inverse, or possibly some other appropriate solver, depending on what is efficient/possible based on the properties of M? Does Octave have a verbose output format that might explain more completely what it has done for a...

Hello Again, I am in the process of writing this algorithm into c++ code to test and I have another question. I have taken the transpose of the three vector matrix v1, v2, v (M=[v1' v2' v']) B=[ -0.0700177 0.382249 -0.289338 0.00349957 ]; A=[ 1.13388 1.77602 -0.679365 -0.729256 ]...

Thanks for the explanations. I am going to code this up and see what results I can get but I have a few more clarification questions. I am not sure what the single quote means in the Octave code you posted, such as, M=[v1' v2' v'] parm = M \ (B-A)' This looks like M is defined as a matrix of...

Thanks, my understanding always gets a bit fuzzy after R3. I have a few clarification questions if you don't mind. Question 1: In the expression for the point we are looking for, $$ \pi = \mathbf B - \xi \mathbf v $$ $$ \xi \text{ = some linear multiplier of } \vec {v} \text { that extends...

Thanks, I'm often a bit unsure about the best place to post. I am not entirely sure about this. In my understanding, providing the space is orthogonal (which it is in this case) any three points can be considered to lie in a Euclidean plane, regardless of the dimensionality of the point...

Hello, I believe that this is the correct forum for this post but please let me know if otherwise. I have the following data in R4, id x y z a B -0.0700177 0.382249 -0.289338 0.00349957 A 1.13388 1.77602 -0.679365...

I am going to re-write the entire problem now because I think I made some errors in my original post. I apologize for the post being long, but I think it is best to do these problems out completely for the benefit of others who may be reading along. For the following original data, id x...

I think so, but I need to do a few things before I can complete my reply. Thanks

I was not sure I was posting this and there doesn't seem to be a way to delete it.

Hello, This algorithm overall is probably more complicated than is correct for the pre-university forum but this question is about a relatively simple aspect of the calculations so I hope that this will be the proper place to ask. I am writing a little program to do some computational geometry...

Looking at the equation above, does the numerator refer to the cross product of vectors (p2-p1) and (p1-p0)? Since the resulting distance Dmin is a scalar, it seems as if this should be a simple product, but "x" often means cross product when vectors are concerned so I thought I should ask...