Matrix references

[DrD]

The responses provided reveal many of the shortcoming's in Prime's ability to deal with matrices. The burden of column replacement using support functions such as DELCOL(), ADDCOL(), and REPLACE(), make difficult what should be quite a simple operation.

The so-called, "dichotomy," HOME vs. CAS, renders useless, what COULD be a useful solution to this problem: Mat[-Column]:=vector, when matrices contain symbolic entries. Negative indices are not supported in CAS.

For example, replacing column 2 of matrix a, with vector b, isn't supported in HOME mode, even by using Mat[-Column]:=vector, when:

a:=[[x2,-x1],[x3,-x2],[x3,-x4]]; // Symbolic entries not allowed in HOME
b:=[[-x1],[-x2],[-x1]];

My original post attempts to emphasize the current weakness, (and encourage further development), in matrix handling methods; within 'both' sides of the HOME / CAS status quo. Understandably, the Primes's authors have much to do, as the Prime undergoes evolution. May I request that improvement in matrix handling be added to "the list?"

Thanks!
-Dale-