Fatal error: Uncaught Error: Call to undefined function noteToFreq() in /home/u294241901/domains/codingace.net/public_html/physics/guitar_string_tension.php:355 Stack trace: #0 /home/u294241901/domains/codingace.net/public_html/physics/guitar_string_tension.php(382): computeExample(25.5, Array, 440) #1 /home/u294241901/domains/codingace.net/public_html/physics/guitar_string_tension.php(459): buildExampleSet() #2 {main} thrown in /home/u294241901/domains/codingace.net/public_html/physics/guitar_string_tension.php on line 355