The following give times of some matrix products using two forms.
The first example uses integers.
The remainder give reproducible results with a range of floating point
numbers. All matrices are of the same shape. What is the reason for the 30
to 1 ratio of times depending on the values of the floating point numbers
for the matrix form, and 7 to 1 ratio for the table form?
Was I wrong to be surprised by these differences?
loadd 'd:\j\j601w\temp\1.ijs'
ts =: 6!:2 , 7!:2
a =: ?. >:200 200 $200
f =: (+/ @: * )"1 1
ts 'a +/ . * |: a'
0.0302508 1.05024e6
ts 'f /~a'
0.0853203 531008
a =:% ?. >:200 200 $200
ts 'a +/ . * |: a'
0.625971 1.05024e6
ts 'f /~a'
0.721225 1.06029e6
a =:% ?. >:200 200 $2000
ts 'a +/ . * |: a'
0.0839973 1.05024e6
ts 'f /~a'
0.165096 1.06029e6
a =:% ?. >:200 200 $20000
ts 'a +/ . * |: a'
0.0277373 1.05024e6
ts 'f /~a'
0.106258 1.06029e6
a =:% ?. >:200 200 $200000
ts 'a +/ . * |: a'
0.0211127 1.05024e6
ts 'f /~a'
0.0991123 1.06029e6
9!:14''
j601/beta/2006-08-23/07:45
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