## 195 Reputation

16 years, 16 days

## Is it possible to find more than one cen...

Maple

This is a problem that intrigues me.

I have been thinking about the distribution of n points, p[1], p[2], ..., p[n] in a scatterplot and I am interested in finding the location of a focal point, A, such that the distance from A to each neighboring point is a minimum. I have worked on a routine and this is given in the attached worksheet. In this example, n=20 and the position of A is determined to be [-3.25, 0.99].

Now - here's my question. Suppose I am interested in n-large and, instead of locating one focal point, A, I wish to obtain several,i.e. A, B, C, etc. such that the distances from each of these to their respective neighboring points is also a minimum.

Does any interested party know if this is possible to do and if so, can anyone suggest an approach or routine? If so, I'd be delighted to understand how to solve for this.

Mapleprimes_Aug_17.mw

## How can I output a data frame for a rec...

Maple

Hello interested parties!

I wish to measure the distance between points in the Cartesian plane and then export the results to Excel using a data frame routine. For the sake of example: suppose there are 2 points, A and B and 6 more points, a,b,c,d,e and f whose coordinates are known.

I am interested in measuring the distance from A to a, b, c, d, e, f and from B to a, b, c, d, e, f. So, a matrix is constructed (see attached) giving the linear separation between eack of the 8 points ... and that's ok.

However, instead of six points of interest, suppose that the number of points becomes very large (e.g. 1,000) and I still need to export to Excel.

Does anyone know of an efficient routine that produces a rectangular matrix to produce a 2 x 6 data frame so that, in the case of large-scale problems the data frame is not overburdened?

Mapleprimes_Matrix.mw

## How to restrict matrix elements to whole...

Maple

A minor question ....

Does anybody know how to format a matrix so all elements are presented in whole numbers?

It's more a niggle than anything .. I want to retain decimals in my worksheet but wish only to have the matrix display integer values.

Thank you!

## How can I measure and tabulate the dista...

Maple

Mapleprimes.mwMapleprimes.mwMapleprimes.mwMapleprimes.mwMapleprimes.mw

Suppose we have a number of points, n, in the x-y plane and the location of each point is known.

I wish to evaluate the straight-line distance from point to point and tabulate these values (i.e. A to B, A to C, A to D, B to C, B to D, etc) and then plot the points in question.

In this attached worksheet, I have given an example of 4 points and I would welcome all suggestions on how to do this.

## What approximation method(s) are used in...

Maple

This is a general question concerning the numerical method(s) used in fsolve.

How can I know what algorithm / method (secant, Newton, etc.) is used when the  fsolve routine is called?

Thank you!

 4 5 6 7 8 9 10 Page 6 of 11
﻿