Dot product: Difference between revisions

=={{header|CLU}}==

<lang clu>% Compute the dot product of two sequences

% If the sequences are not the same length, it signals length_mismatch

% Any type may be used as long as it supports addition and multiplication

dot_product = proc [T: type] (a, b: sequence[T])

returns (T) signals (length_mismatch, empty, overflow)

where T has add: proctype (T,T) returns (T) signals (overflow),

mul: proctype (T,T) returns (T) signals (overflow)

sT = sequence[T]

% throw errors if necessary

if sT$size(a) ~= sT$size(b) then signal length_mismatch end

if sT$empty(a) then signal empty end

% because we don't know what type T is yet, we can't instantiate it

% with a default value, so we use the first pair from the sequences

s: T := sT$bottom(a) * sT$bottom(b) resignal overflow

for i: int in int$from_to(2, sT$size(a)) do

s := s + a[i] * b[i] resignal overflow

end

return(s)

end dot_product

% calculate the dot product of the given example

start_up = proc ()

po: stream := stream$primary_output()

a: sequence[int] := sequence[int]$[1, 3, -5]

b: sequence[int] := sequence[int]$[4, -2, -1]

stream$putl(po, int$unparse(dot_product[int](a,b)))

end start_up</lang>

{{out}}

<pre>3</pre>