# Coverage for rocketcea\Goal.py : 99%

## 79 statements 78 run 1 missing 0 excluded

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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 | from math import * # This CLASS version of goal finder should allow nested Goal loops # The world's best root finder by Jack Crenshaw # ... turned into world's best "goal-value" finder by Charlie Taylor class Goal( object ): def __call__(self, xval=0.0): ierror = 1 # needs to be reset by cren_goal call to avoid failValue logic try: X, ierror = self.cren_goal(self.goalVal, self.minX, self.maxX, self.funcOfX, self.tolerance, self.maxLoops) except: if self.verbose: print( "ERROR unrecoverable in Goal.py") X = self.maxX if ierror: if (self.failValue==None): X = self.maxX if self.verbose: print( "returned an ERROR=%s from cren_goal in goalFind.py"%str(ierror)) print( "goalVal, minX, maxX, funcOfX",self.goalVal, self.minX, self.maxX, self.funcOfX.__name__) print( "using X value=",X) else: X = self.failValue return X, ierror def __init__(self, goalVal=0.0, minX=0.0, maxX=1000.0, verbose=True, funcOfX=None, tolerance=1.0E-4, maxLoops=40, failValue=None): # initialize properties self.goalVal = goalVal self.minX = minX self.maxX = maxX self.funcOfX = funcOfX self.tolerance = tolerance self.maxLoops = maxLoops self.failValue = failValue self.verbose = verbose def cren_goal(self, goal, x0, x2, f, eps, imax): # ierror parameters SUCCESS = 0 MyBAD_DATA = 1 NO_CONVERGENCE = 2 xmlast = x0 y0 = f(x0) - goal if (y0 == 0.0): return x0, SUCCESS y2 = f(x2) - goal if (y2 == 0.0): return x2, SUCCESS if(y2 * y0 > 0.0): return x0, MyBAD_DATA for i in range(imax): #print( 'I=',i,' of ',imax) x1 = 0.5 * (x2 + x0) y1 = f(x1) - goal if (y1 == 0.0) : return x1, SUCCESS if (abs (x1 - x0) < eps) : return x1, SUCCESS if (y1 * y0 > 0.0): x0,x2,y0,y2 = (x2,x0,y2,y0) # switch points 0 and 2 y10 = y1 - y0 y21 = y2 - y1 y20 = y2 - y0 if (y2 * y20 < 2.0 * y1 * y10): x2,y2 = (x1,y1) else: b = (x1 - x0) / y10 c = (y10 -y21) / (y21 * y20) xm = x0 - b * y0 * (1.0-c * y1) ym = f(xm) - goal if (ym == 0.0) : return xm, SUCCESS if (abs (xm - xmlast) < eps) : return xm, SUCCESS xmlast = xm if (ym * y0 < 0.0): x2,y2 = (xm,ym) else: x0,y0,x2,y2 = (xm,ym,x1,y1) return x1, NO_CONVERGENCE if __name__ == "__main__": #self test def FofX(x): #print( 'calling FofX with x=',x) return x**3 - x**2 + x - 11.875 print( '======================================================') print( '----->Answer should be = 2.5') print( 'with tolerance=1.0E-3 =') G = Goal(goalVal=0.0, minX=0.0, maxX=57.123, funcOfX=FofX, tolerance=1.0E-3, maxLoops=40, failValue=None) print( G()) print( 'with tolerance=1.0E-20 =') G2 = Goal(goalVal=0.0, minX=0.0, maxX=57.123, funcOfX=FofX, tolerance=1.0E-20, maxLoops=40, failValue=None) print( G2())