summaryrefslogtreecommitdiff
path: root/ext/bigdecimal/sample/linear.rb
diff options
context:
space:
mode:
authorshigek <shigek@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2003-04-24 13:37:32 +0000
committershigek <shigek@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2003-04-24 13:37:32 +0000
commitcff57b4a267b61561b04c527b5ce04d64cbcf78b (patch)
tree1196b15571b715ea69fee1ea90ce8bb2e958e787 /ext/bigdecimal/sample/linear.rb
parent558c428b72e666a58d6819cb45b63e75f15ae537 (diff)
Dir. rearrangement according to the suggestions from Minero Aoki.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@3722 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Diffstat (limited to 'ext/bigdecimal/sample/linear.rb')
-rw-r--r--ext/bigdecimal/sample/linear.rb46
1 files changed, 46 insertions, 0 deletions
diff --git a/ext/bigdecimal/sample/linear.rb b/ext/bigdecimal/sample/linear.rb
new file mode 100644
index 00000000000..f93404fb6ff
--- /dev/null
+++ b/ext/bigdecimal/sample/linear.rb
@@ -0,0 +1,46 @@
+#!/usr/local/bin/ruby
+
+#
+# linear.rb
+#
+# Solves linear equation system(A*x = b) by LU decomposition method.
+# where A is a coefficient matrix,x is an answer vector,b is a constant vector.
+#
+require "bigdecimal"
+require "ludcmp"
+
+include LUSolve
+
+def rd_order
+ printf("Number of equations ?")
+ n = gets().chomp.to_i
+end
+
+zero = BigDecimal::new("0.0")
+one = BigDecimal::new("1.0")
+
+while (n=rd_order())>0
+ a = []
+ as= []
+ b = []
+ printf("\nEnter coefficient matrix element A[i,j]\n");
+ for i in 0...n do
+ for j in 0...n do
+ printf("A[%d,%d]? ",i,j); s = gets
+ a <<=BigDecimal::new(s);
+ as<<=BigDecimal::new(s);
+ end
+ printf("Contatant vector element b[%d] ? ",i);b<<=BigDecimal::new(gets);
+ end
+ printf "ANS="
+ x = lusolve(a,b,ludecomp(a,n,zero,one),zero)
+ p x
+ printf "A*x-b\n"
+ for i in 0...n do
+ s = zero
+ for j in 0...n do
+ s = s + as[i*n+j]*x[j]
+ end
+ p s-b[i]
+ end
+end