sparse result matrix [file name]

  Interactively create a sparse matrix over the current ring. The system first prompts for the number of rows and columns, and then prompts for the index and polynomial value of each non-zero entry.

If a file name is given, the command uses this file as input, and the system doesn't display any prompt lines. Thus "sparse m file" is the same as "sparse m <file", where the input has been redirected to come from ``file'', except that no prompts are displayed.

For example, to create a 5 by 6 matrix named m56,

%  sparse m56
! number of rows    ?  5
! number of columns ?  6
! row column value  ?  1 1 a2+b2+cd
! row column value  ?  3 5 abc
! row column value  ?  5 6 -1
! row column value  ? <return>

%  type m
; a2-b2     2c 0           
; a2+2ab+b2 3d ac+bc-ad-bd

The row, column, and polynomial expression are separated by blanks. The row and column can be any integer expressions. To stop the input of entries, simply type <return> on your terminal. The remaining entries are set to zero.

The base ring of the matrix is the current ring.