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-rw-r--r--ext/bigdecimal/sample/linear.rb67
1 files changed, 45 insertions, 22 deletions
diff --git a/ext/bigdecimal/sample/linear.rb b/ext/bigdecimal/sample/linear.rb
index c4a428e642..7c8ca263eb 100644
--- a/ext/bigdecimal/sample/linear.rb
+++ b/ext/bigdecimal/sample/linear.rb
@@ -6,43 +6,66 @@
# 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.
#
+# USAGE:
+# ruby linear.rb [input file solved]
+#
+
require "bigdecimal"
require "ludcmp"
-include LUSolve
+#
+# NOTE:
+# Change following BigDecimal::limit() if needed.
+BigDecimal::limit(100)
+#
-def rd_order
- printf("Number of equations ?")
- n = gets().chomp.to_i
+include LUSolve
+def rd_order(na)
+ printf("Number of equations ?") if(na <= 0)
+ n = ARGF.gets().to_i
end
-BigDecimal::limit(100)
-
+na = ARGV.size
zero = BigDecimal::new("0.0")
one = BigDecimal::new("1.0")
-while (n=rd_order())>0
+while (n=rd_order(na))>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);
+ if na <= 0
+ # Read data from console.
+ 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 = ARGF.gets
+ a << BigDecimal::new(s);
+ as << BigDecimal::new(s);
+ end
+ printf("Contatant vector element b[%d] ? ",i); b << BigDecimal::new(ARGF.gets);
+ end
+ else
+ # Read data from specified file.
+ printf("Coefficient matrix and constant vector.\n");
+ for i in 0...n do
+ s = ARGF.gets
+ printf("%d) %s",i,s)
+ s = s.split
+ for j in 0...n do
+ a << BigDecimal::new(s[j]);
+ as << BigDecimal::new(s[j]);
+ end
+ b << BigDecimal::new(s[n]);
+ end
end
- printf "ANS="
x = lusolve(a,b,ludecomp(a,n,zero,one),zero)
- p x
- printf "A*x-b\n"
+ printf("Answer(x[i] & (A*x-b)[i]) follows\n")
for i in 0...n do
- s = zero
- for j in 0...n do
+ printf("x[%d]=%s ",i,x[i].to_s)
+ s = zero
+ for j in 0...n do
s = s + as[i*n+j]*x[j]
- end
- p s-b[i]
+ end
+ printf(" & %s\n",(s-b[i]).to_s)
end
end