Measure distance between all points

JumpingAC — Fri, 01 Mar 2019 20:54:45 GMT

I am trying to determine a meausre of how distance from a point effects measurements to find a minimum / maximum point within range of points.

I tried to do this in the attached files but I cannot find a way to do this programatically. I tried to do this by concatenating a table of N rows, N times, copying the XY coulmn, sorting Y then X then pastingn this sorted column into the NxN table.

I tried to do this with EVAL / SUBSTITUTION but cannot get it to successfuly execute.

Re: Measure distance between all points

Mark_Bailey — Fri, 01 Mar 2019 20:58:48 GMT

Did you see the Distance() function? Here is an example from the Scripting Index of a script using it:

Names Default To Here( 1 );
/*1-D example*/
exX1 = [1, 2, 3, 4];
exX2 = [2, 4, 6, 8]; 
/*Compute squared Euclidean distance*/
exD = Distance( exX1, exX2 ); 
/*Verify result*/
exDm = J( 4, 4, . );
For( exi = 1, exi <= 4, exi++,
	For( exj = 1, exj <= 4, exj++,
		exDm[exi, exj] =
		Sum( (exX1[exi, 0] - exX2[exj, 0]) ^ 2 )
	)
);
Show( exDm == exD ); 

/*2-D example*/
exX1 = [1 1, 2 2, 3 3, 4 4];
exX2 = [2 1, 4 2, 6 0, 8 7]; 
/*Compute squared Euclidean distance*/
exD = Distance( exX1, exX2 ); 
/*Verify result*/
exDm = J( 4, 4, . );
For( exi = 1, exi <= 4, exi++,
	For( exj = 1, exj <= 4, exj++,
		exDm[exi, exj] =
		Sum( (exX1[exi, 0] - exX2[exj, 0]) ^ 2 )
	)
);
Show( exDm == exD ); 

/*2-D example*/
exX1 = [1 1, 2 2, 3 3, 4 4];
exX2 = [2 1, 4 2, 6 0, 8 7]; 
/*Compute squared Euclidean distance, with a scaler [0.5 2.0]*/
exD = Distance( exX1, exX2, [0.5 2.0] ); 
/*Verify result*/
exDm = J( 4, 4, . );
For( exi = 1, exi <= 4, exi++,
	For( exj = 1, exj <= 4, exj++,
		exDm[exi, exj] =
		Sum(
			[0.5 2.0] :* (
			Abs( exX1[exi, 0] - exX2[exj, 0] ) ^ 2)
		)
	)
);
Show( exDm == exD ); 

/*2-D example*/
exX1 = [1 1, 2 2, 3 3, 4 4];
exX2 = [2 1, 4 2, 6 0, 8 7]; 
/*Compute squared Euclidean distance, with scalers [0.5 2.0] and powers [1.5 2.0]*/
exD = Distance( exX1, exX2, [0.5 2.0], [1.5 2.0] ); 
/*Verify result*/
exDm = J( 4, 4, . );
For( exi = 1, exi <= 4, exi++,
	For( exj = 1, exj <= 4, exj++,
		exDm[exi, exj] =
		Sum(
			[0.5 2.0] :* (
			Abs( exX1[exi, 0] - exX2[exj, 0] ) :^ [
			1.5 2.0])
		)
	)
);
Show( exDm == exD );

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Measure distance between all points

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