Programmer Guide/Command Reference/EVAL/dist: Difference between revisions
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Compute the | Compute the distance or distance-matrix. | ||
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;Usage 1: | ;Usage 1: | ||
Revision as of 10:58, 20 April 2011
Compute the distance or distance-matrix.
- Usage 1
dist(xscalar, yscalar)dist(xvector, yvector)- Result 1
- The euclidan distance dscalar of x and y. The two arguments must be scalars or vectors with the same length.
- Usage 2
dist(xvector)dist(xmatrix)- Result 2
- The matrix d with the euclidian distances of all elements or row vectors of x. The result is a matrix with
nrow(x)rows and columns.
xvector -> d[i,j] = dist(x[i], x[j]) xmatrix -> d[i,j] = dist(x[i,*], x[j,*]) with: i,j = 0 .. ncol(x)
- Usage 3
dist(xvector, yscalar)dist(xmatrix, yvector)- Result 3
- The vector d with the euclidian distances of all elements or row vectors of x to y. The result is a vector with
nrow(x)rows and columns.
xvector,yscalar -> d[i] = dist(x[i], y) xmatrix,yvector -> d[i,j] = dist(x[i,*], y) ( ncol(x)must be equal tonrow(y)!)with: i = 0 .. ncol(x)
- Usage 4
dist(xmatrix, flag)- Result 4
- The matrix d with the euclidian distances of the row vectors (flag=0) or column vectors (flag=1) or x.
flag=0 -> d[i,j] = dist(x[i,*], x[j,*]) , with: i,j = 0 .. nrow(x)flag=1 -> d[i,j] = dist(x[*,i], x[*,j]) , with: i,j = 0 .. ncol(x)