# eq: Comparison of two magic squares In magic: create and investigate magic squares

## Description

Compares two magic squares according to Frenicle's method. Mnemonic is the old Fortran “.GT.” (for “Greater Than”) comparison et seq.

To compare magic square `a` with magic square `b`, their elements are compared in rowwise order: `a[1,1]` is compared with `b[1,1]`, then `a[1,2]` with `b[1,2]`, up to `a[n,n]`. Consider the first element that is different, say `[i,j]`. Then `a<b` if `a[i,j]<b[i,j]`.

The generalization to hypercubes is straightforward: comparisons are carried out natural order.

## Usage

 ``` 1 2 3 4 5 6 7 8 9 10 11 12``` ```eq(m1, m2) ne(m1, m2) gt(m1, m2) lt(m1, m2) ge(m1, m2) le(m1, m2) m1 %eq% m2 m1 %ne% m2 m1 %gt% m2 m1 %lt% m2 m1 %ge% m2 m1 %le% m2 ```

## Arguments

 `m1` First magic square `m2` Second magic square

## Note

Rather clumsy function definition due to the degenerate case of testing two identical matrices (`min(NULL)` is undefined).

The two arguments are assumed to be matrices of the same size. If not, an error is given.

## Author(s)

Robin K. S. Hankin

`as.standard`
 ```1 2``` ```magic(4) %eq% magic.4n(1) eq(magic(4) , magic.4n(1)) ```