From: Gustaf Thorslund <gustaf@thorslund.org>
Subject: X : Real_Vector := Solve(A => A, X => B); -- Why X as argument name?
Date: Sun, 23 Dec 2012 23:28:13 +0100
Date: 2012-12-23T23:28:13+01:00 [thread overview]
Message-ID: <871uegmmiq.fsf@katthult.thorslund.org> (raw)
-- why_x.adb by confused Gustaf Thorslund
with Ada.Numerics.Real_Arrays; use Ada.Numerics.Real_Arrays;
with Ada.Text_IO; use Ada.Text_IO;
procedure Why_X is
-- Let's say we have an equation Ax = b according to the notation
from
-- http://en.wikipedia.org/wiki/Matrix_(mathematics)#Linear_equations
-- where A and b are known while x is unknown.
A : Real_Matrix(1..1, 1..1) := (others => (others => 2.0));
B : Real_Vector(1..1) := (others => 12.0);
-- x is found using
-- function Solve (A : Real_Matrix; X : Real_Vector) return
-- Real_Vector;
X : Real_Vector := Solve(A => A, X => B); -- Why X as argument name?
begin
for I in X'Range loop
Put_Line(Float'Image(X(I)));
end loop;
end Why_X;
-- Executing the program gives
-- $ ./why_x
-- 6.00000E+00
-- So we found the expected value of x.
-- Was it a misstake to use X as argument name in Solve?
next reply other threads:[~2012-12-23 22:28 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-12-23 22:28 Gustaf Thorslund [this message]
2012-12-24 8:33 ` X : Real_Vector := Solve(A => A, X => B); -- Why X as argument name? Niklas Holsti
2012-12-24 11:50 ` Simon Wright
2012-12-24 12:58 ` Niklas Holsti
2012-12-24 21:25 ` Gustaf Thorslund
2012-12-24 20:42 ` Gustaf Thorslund
2012-12-24 20:10 ` jpwoodruff
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