expr2cf

Converts a simple mathematical expression to a continued fraction sequence

Requirements

• a C++ compiler which supports C++11
• the GNU Multiple Precision Arithmetic Library
• the rational C++ template class

Usage/examples

• to evaluate an expression:
  echo "2 + 0.8031975" | expr2cf => [2, 1, 4, 12, 3, 4, 2, 1, 1, 1, 1, 2, 1, 1, 5]

• to get an approximated fraction of pi (from 18 decimal digits):
  echo "scale=18; 4*a(1)" | BC_LINE_LENGTH=0 bc -l | expr2cf | cf2expr
  => 14308127635/4554418479

• to get an approximated fraction of the golden ratio (Phi):
  echo "[1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1]" | cf2expr
  => 6765/4181