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mutableIdentity(Ring,ZZ) -- make a mutable identity matrix

Synopsis

Function: mutableIdentity
Usage:

mutableIdentity(R,nrows)
Inputs:
- R, a ring
- nrows, an integer
Optional inputs:
- Dense => ..., default value true, whether the encoding of the matrix should be dense or not: see MutableMatrix
Outputs:
- a mutable matrix, an nrows by nrows mutable identity matrix filled with elements of the ring R

Description

i1 : m = mutableIdentity(QQ,10)

o1 = | 1 0 0 0 0 0 0 0 0 0 |
     | 0 1 0 0 0 0 0 0 0 0 |
     | 0 0 1 0 0 0 0 0 0 0 |
     | 0 0 0 1 0 0 0 0 0 0 |
     | 0 0 0 0 1 0 0 0 0 0 |
     | 0 0 0 0 0 1 0 0 0 0 |
     | 0 0 0 0 0 0 1 0 0 0 |
     | 0 0 0 0 0 0 0 1 0 0 |
     | 0 0 0 0 0 0 0 0 1 0 |
     | 0 0 0 0 0 0 0 0 0 1 |

o1 : MutableMatrix

i2 : m_(5,5) = 11/13

     11
o2 = --
     13

o2 : QQ

i3 : m

o3 = | 1 0 0 0 0 0     0 0 0 0 |
     | 0 1 0 0 0 0     0 0 0 0 |
     | 0 0 1 0 0 0     0 0 0 0 |
     | 0 0 0 1 0 0     0 0 0 0 |
     | 0 0 0 0 1 0     0 0 0 0 |
     | 0 0 0 0 0 11/13 0 0 0 0 |
     | 0 0 0 0 0 0     1 0 0 0 |
     | 0 0 0 0 0 0     0 1 0 0 |
     | 0 0 0 0 0 0     0 0 1 0 |
     | 0 0 0 0 0 0     0 0 0 1 |

o3 : MutableMatrix

See also

mutableMatrix -- make a mutable matrix

Ways to use this method:

mutableIdentity(Ring,ZZ) -- make a mutable identity matrix
mutableIdentity(RingFamily,ZZ)