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ASME's Mechanical Engine…ing Toolkit 1997 December
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ASME's Mechanical Engineering Toolkit 1997 December.iso
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prlg195b.lzh
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SAMPLES.LZH
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MATRIX.PRO
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1986-07-20
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con_num_list( [H|T] ) :- rnum( H ), con_num_list( T ).
con_num_list( [] ).
/* To multiply a row by a column: */
mat_mult( [H1|T1], [H2|T2], res ) :-
mat_mult1( [H1|T1], [H2|T2, 0, res ).
mat_mult1( [H1|T1], [H2|T2], sum, res ) :-
sum is sum + H1 * H2,
mat_mult1( T1, T2, sum, res ).
mat_mult1( [], [], sum, res ) :- res = sum.
/* To get the nth element of a list:
Let us assume a matrix in the form of a list of columns:
[ L1, L2.....]
listel( N, [H|T], X ) :-
N > 0,
N is N - 1,
listel( N, T, X ).
listel( N, [H|_], X ) :- X = H.
/* Below, X, Y are the "coordinates".
L is the complex list representing the array.
element is the returned value. */
matrix_el( X, Y, L, element ) :-
/* First get the row, represented as an element "rowel" in list L */
listel( X, L, rowel ),
/* And now the value contained within the row. */
listel( Y, rowel, element ).