func exprGrow(e ExprType, egfunc ExprGenFunc, egp *prob.TreeParams, rng *rand.Rand) Expr {
if e == -1 {
return egfunc(egp, rng)
}
switch {
case e == TIME:
return NewTime()
case e == VAR:
p := egp.UsableVars[rng.Intn(len(egp.UsableVars))]
return NewVar(p)
case e == CONSTANT:
i := egp.CoeffCount
egp.CoeffCount++
return NewConstant(i)
case e == CONSTANTF:
return NewConstantF(rng.NormFloat64() * 2.0)
case e == SYSTEM:
return NewSystem(rng.Intn(egp.NumSys))
case e == NEG:
egp.CurrDepth++
return NewNeg(egfunc(egp, rng))
case e == ABS:
egp.CurrDepth++
return NewAbs(egfunc(egp, rng))
case e == SQRT:
egp.CurrDepth++
return NewSqrt(egfunc(egp, rng))
case e == SIN:
egp.CurrDepth++
egp.InTrig = true
tmp := NewSin(egfunc(egp, rng))
egp.InTrig = false
return tmp
case e == COS:
egp.CurrDepth++
egp.InTrig = true
tmp := NewCos(egfunc(egp, rng))
egp.InTrig = false
return tmp
case e == TAN:
egp.CurrDepth++
egp.InTrig = true
tmp := NewTan(egfunc(egp, rng))
egp.InTrig = false
return tmp
case e == EXP:
egp.CurrDepth++
return NewExp(egfunc(egp, rng))
case e == LOG:
egp.CurrDepth++
return NewLog(egfunc(egp, rng))
case e == POWI:
egp.CurrDepth++
return NewPowI(egfunc(egp, rng), (rng.Int()%7)-3)
case e == POWF:
egp.CurrDepth++
return NewPowF(egfunc(egp, rng), rng.Float64()*3.0)
case e == POWE:
egp.CurrDepth++
return NewPowE(egfunc(egp, rng), egfunc(egp, rng))
case e == ADD:
egp.CurrDepth++
add := NewAdd()
add.Insert(egfunc(egp, rng))
add.Insert(egfunc(egp, rng))
return add
case e == MUL:
egp.CurrDepth++
mul := NewMul()
mul.Insert(egfunc(egp, rng))
mul.Insert(egfunc(egp, rng))
return mul
case e == DIV:
egp.CurrDepth++
return NewDiv(egfunc(egp, rng), egfunc(egp, rng))
}
return NewNull()
}
