Contents - Index

BINARY OPERATIONS

ADD - Syntax: add(<mat1>,<mat2>,...).  Takes the sum of corresponding cells across two or more matrices. Example:

AVERAGE - Syntax: avg(<mat1>,<mat2>,...).  Takes the average value of corresponding cells across two or more matrices.Example:

c = avg(a,b)

BOOLEAN PRODUCT - Syntax: bprod(<mat1>,<mat2>).  Boolean multiplication of two binary matrices.  The Boolean product is a matrix product which is automatically dichotomized to 1s and 0s.  (ABij > 0 goes to 1)  Example:

CONGRU - Syntax: congru(<tarcoord>,<incoord>). Rotates and stretches a set of input coordinates (such as MDS coordinates) to most closely approximate a set of target coordinates.

bestfit = congru(observed,mdscoord)

CORR - Syntax: corr(<mat1>[, <mat2>]).  With one parameter, the function generates a matrix with the correlations between the rows within the dataset.  With two parameters, it generates a matrix of the correlations between all columns in two datasets.

cortable = corr(campnet)
or
cortable = corr(campnet,davis)

DIVIDE - Syntax: div(<mat1>,<mat2>).  Divides each cell of <mat1> by the corresponding cell of <mat2>.  Divisions by zero result in missing values. Example:

junk = div(c:\atlanta\corrmat,mcorr)

EQUAL - Syntax: eq(<mat1>,<mat2>,...).  Compares two or more matrices and puts a value of 1 where all matrices have the same value and a 0 where any are different.  For example, typing

junk = eq(a,b)

gives a new binary matrix called junk which has 1s in those cells where a and b have the same value, and has 0s elsewhere.

GREATER THAN - Syntax: gt(<mat1>,<mat2>,...).  Compares two or more matrices, creating a new matrix which is 1 for all cells where the first matrix is strictly larger than all subsequent matrices, and 0 elsewhere.

c = gt(a,b)

In the example, the matrix c will have 1s only in those cells where a dominates b.

GREATER THAN OR EQUAL TO - Syntax: ge(<mat1>,<mat2>,...).  Compares two or more matrices, creating a new matrix which is 1 for all cells where the first matrix is larger than or equal to all subsequent matrices, and 0 elsewhere.

c = ge(a,b)

In the example, the matrix c will have 1s only in those cells where a is not dominated by b.

LESS THAN - Syntax: 1t(<mat1>,<mat2>,...).  Compares two or more matrices, creating a new matrix which is 1 for all cells  where the first matrix is strictly less than all subsequent matrices, and 0 elsewhere.

c = lt(a,b)

In the example, the matrix c will have 1s only in those cells where a is dominated by b.

LESS THAN OR EQUAL TO - Syntax: le(<mat1>,<mat2>,...).  Compares two or more matrices, creating a new matrix which is 1 for all cells where the first matrix is less than or equal to all subsequent matrices, and 0 elsewhere.

c = le(a,b)

In the example, the matrix c will have 1s only in those cells where a is smaller than or equal to the value of b.

MAXIMUM - Syntax: max(<mat1>,<mat2>,...).  Takes the largest value of corresponding cells across two or more matrices.

c = max(a,b)

MINIMUM - Syntax: min(<mat1>,<mat2>,...).  Takes the smallest value of corresponding cells across two or more matrices.

c = min(a,b)

MULTIPLY - Syntax: mult(<mat1>,<mat2>,...).  Takes the product of corresponding cells across two or more matrices.

c = mult(a,b)

PRODUCT - Syntax: prod(<mat1>,<mat2>,...).  Matrix multiplication of two matrices.  This is NOT element-wise multiplication of corresponding values (see MULTIPLY). Example:

In the example, the business matrix is pre-multiplied by marriage.

REPLACENA - Syntax: replacena(<mat1>,<mat2>).  Fills in missing values in mat1 with the corresponding value from mat2.

nomissing = replacena(a,b)

SQUARED DIFFERENCE - Syntax: sqrdif(<mat1>,<mat2>,...). Takes the squared difference of corresponding cells across two or more matrices.

c = sqrdif(a,b)

One application of this function is to compare a data matrix with a predicted matrix, based on a least squares criterion.

SUBTRACT - Syntax: sub(<mat1>,<mat2>,...).  Subtracts the values of corresponding cells of two or more matrices from the first matrix mentioned.

c = sub(a,b)

In the example, the values of b are subtracted from the values of a.

FURTHER INFORMATION

Uniary Operations

Inner Products

Procedures

Matrix Algebra