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Re: matrix of coefficients?

RE: matrix of coefficients?
Martin McClain, WRITES: 

If  varsN = a list of N variables,  and if
exprsN = a list of of N expressions, each one linear in the variables of varsN,
Is there some operator (that I haven't found yet), or some clever way to
use a nonobvious operator, to get the matrix of coefficients? 
If I interpret the question properly, I believe an answer is: 

{v[1], v[2], v[3]}

exprsN=Table[Sum[a[i,j] varsN[[i]],{i,3}],{j,3}];
exprsN //TableForm
a[1, 1] v[1] + a[2, 1] v[2] + a[3, 1] v[3]
a[1, 2] v[1] + a[2, 2] v[2] + a[3, 2] v[3]
a[1, 3] v[1] + a[2, 3] v[2] + a[3, 3] v[3]

table=Table[ Coefficient[exprsN[[i]],varsN[[j]] ],{i,3},{j,3}];
table //TableForm
a[1, 1]   a[2, 1]   a[3, 1]
a[1, 2]   a[2, 2]   a[3, 2]
a[1, 3]   a[2, 3]   a[3, 3]

Fredrick I. Olness

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