public static bool FindSolution(double inputGuess, double inputStepSize,
double outputGoal, Comparison <double> compareOutputs, TryGetOutput tryGetOutput, out double input)
{
Debug.Assert(compareOutputs != null);
Debug.Assert(tryGetOutput != null);
Debug.Assert(inputStepSize > 0);
double lowerGuess, upperGuess;
input = inputGuess;
double output;
if (!tryGetOutput(input, out output))
{
return(false);
}
int comparison = compareOutputs(output, outputGoal);
switch (comparison)
{
default:
case 0:
return(true);
case -1:
do
{
lowerGuess = input;
input += inputStepSize;
if (!tryGetOutput(input, out output))
{
return(false);
}
comparison = compareOutputs(output, outputGoal);
if (comparison == 0)
{
return(true);
}
} while (comparison < 0);
upperGuess = input;
break;
case +1:
do
{
upperGuess = input;
input -= inputStepSize;
if (!tryGetOutput(input, out output))
{
return(false);
}
comparison = compareOutputs(output, outputGoal);
if (comparison == 0)
{
return(true);
}
} while (comparison > 0);
lowerGuess = input;
break;
}
Debug.Assert(lowerGuess < upperGuess);
while (true)
{
input = (lowerGuess + upperGuess) / 2;
if (!tryGetOutput(input, out output))
{
return(false);
}
switch (compareOutputs(output, outputGoal))
{
case 0:
return(true);
case -1:
lowerGuess = input;
break;
case +1:
upperGuess = input;
break;
}
}
}
public static bool FindSolution(double inputGuess, double inputStepSize,
double outputGoal, Comparison<double> compareOutputs, TryGetOutput tryGetOutput, out double input)
{
Debug.Assert(compareOutputs != null);
Debug.Assert(tryGetOutput != null);
Debug.Assert(inputStepSize > 0);
double lowerGuess, upperGuess;
input = inputGuess;
double output;
if (!tryGetOutput(input, out output))
return false;
int comparison = compareOutputs(output, outputGoal);
switch (comparison) {
default:
case 0:
return true;
case -1:
do {
lowerGuess = input;
input += inputStepSize;
if (!tryGetOutput(input, out output))
return false;
comparison = compareOutputs(output, outputGoal);
if (comparison == 0)
return true;
} while (comparison < 0);
upperGuess = input;
break;
case +1:
do {
upperGuess = input;
input -= inputStepSize;
if (!tryGetOutput(input, out output))
return false;
comparison = compareOutputs(output, outputGoal);
if (comparison == 0)
return true;
} while (comparison > 0);
lowerGuess = input;
break;
}
Debug.Assert(lowerGuess < upperGuess);
while (true) {
input = (lowerGuess + upperGuess) / 2;
if (!tryGetOutput(input, out output))
return false;
switch (compareOutputs(output, outputGoal)) {
case 0:
return true;
case -1:
lowerGuess = input;
break;
case +1:
upperGuess = input;
break;
}
}
}
