Expression Transformation (functions/simplification.py)

functions/simplification.py provides the unified entry simplifies, which selects a transformation by the integer method. method is an integer 0–12; zhuyuan / huanyuan / huanyuanshi are only used by some methods. The function returns a single SymPy expression (simplified by radsimp), not a list of strings.

simplifies — expression transformation

Purpose: algebraically transform in_expr in the way selected by method and return the simplified expression.

def simplifies(in_expr, method, zhuyuan, huanyuan, huanyuanshi, fs):
    ...

Param	Type	Meaning
in_expr	str	expression to transform, e.g. "x**2 - 1"
method	int	transformation index 0–12 (see table below); selects the actual SymPy call
zhuyuan	str	main variable; used only by method=3 (collect) and method=12 (substitute)
huanyuan	str	substitution symbol (target symbol); only method=12
huanyuanshi	str	substitution expression (replaces zhuyuan); only method=12
fs	dict	function dictionary

Returns: a single SymPy expression from radsimp(...).

method index table

method	name	actual call	params used
0	simplify	simplify	—
1	expand	expand	—
2	factor	factor	—
3	collect (combine like terms)	collect(expr, zhuyuan)	zhuyuan
4	cancel	cancel	—
5	apart (partial fractions)	apart	—
6	trigsimp	trigsimp	—
7	expand_trig	expand_trig	—
8	powsimp	powsimp	—
9	expand_power_exp	expand_power_exp	—
10	expand_log	expand_log	—
11	logcombine	logcombine	—
12	substitute & expand	expand(expr.subs(zhuyuan, solve(Eq(huanyuan, huanyuanshi), zhuyuan)[0]))	zhuyuan, huanyuan, huanyuanshi

Warning

Except for method=3 and method=12, all other methods ignore the values of zhuyuan / huanyuan / huanyuanshi.

Example

python simplifies("x**2-1", 2, "x", "", "", {}) # -> (x - 1)*(x + 1) (factor) simplifies("x**2", 12, "x", "t", "y+1", {}) # -> (y + 1)**2 (substitute x with t=y+1) simplifies("1/sqrt(2)", 0, "x", "", "", {}) # -> sqrt(2)/2 (simplify)