assertEquals("((2 + 3 + 4) / 3)" , ctx.mapFunction("avg","2","3","4"));
assertEquals("(3)" , ctx.mapFunction("median","1","2","3","4","5"));
assertEquals("( 0.5 * 3 + 0.5 * 4 )" , ctx.mapFunction("median","1","2","3","4","5","6"));
assertEquals("(Math.log10(2))" , ctx.mapFunction("log10","2"));
assertEquals("(Math.log(2))" , ctx.mapFunction("ln","2"));
assertEquals("(Math.sqrt(2))" , ctx.mapFunction("sqrt","2"));
assertEquals("(Math.abs(2))" , ctx.mapFunction("abs","2"));
assertEquals("(Math.exp(2))" , ctx.mapFunction("exp","2"));
assertEquals("(Math.pow(2,3))" , ctx.mapFunction("pow","2","3"));
assertEquals("(1)" , ctx.mapFunction("pow","0","0"));