public void Test_DoCalc()
{
//arrange
OhmValuesModel ohmValues = new OhmValuesModel();
OhmValuesModel ohmValues_check = new OhmValuesModel
{
ohms = 126000,
tolerance = 0.05M,
low = 119700,
high = 132300
};
OhmCalcModel ohmCalc = new OhmCalcModel();
List <int> digits = new List <int>();
digits.Add(1);
digits.Add(2);
digits.Add(6);
ohmCalc.significantFigures = digits;
ohmCalc.multiplier = 1000;
ohmCalc.tolerance = 0.05M;
//act
ohmValues = Utilities.DoCalc(ohmCalc);
//assert
Assert.AreEqual(ohmValues_check.ohms, ohmValues.ohms);
Assert.AreEqual(ohmValues_check.tolerance, ohmValues.tolerance);
Assert.AreEqual(ohmValues_check.low, ohmValues.low);
Assert.AreEqual(ohmValues_check.high, ohmValues.high);
}
/// <summary>
/// Does the actual calculation of resistance, tolerance, low and high values for a resistor, given the derived band values.
/// </summary>
/// <param name="ocm_input"></param>
/// <returns>Returns an object containing calc'ed values</returns>
public static OhmValuesModel DoCalc(OhmCalcModel ocm_input)
{
//init returning object
OhmValuesModel ovm_output = new OhmValuesModel();
ovm_output.ohms = 0;
ovm_output.tolerance = 0;
ovm_output.low = 0;
ovm_output.high = 0;
//use all significant figures and turn into a concat'ed string
string sigfigs = string.Empty;
foreach (var sigfig in ocm_input.significantFigures)
{
sigfigs += sigfig.ToString();
}
//convert concated significant figures into a calculable number and calc it against multiplier and tolerance values.
int iOhms;
if (int.TryParse(sigfigs, out iOhms) && (iOhms > 0))
{
//sigfig bands converted to number, multiply parsed number with multiplier value, set ohms value as decimal to retain numbers on each side of decimal place.
ovm_output.ohms = iOhms;
if (ocm_input.significantFigures.Count() > 1)
{
ovm_output.ohms = iOhms * ocm_input.multiplier;
}
//now calculate the low and high tolerace
ovm_output.low = ovm_output.ohms - (ovm_output.ohms * ocm_input.tolerance);
ovm_output.high = ovm_output.ohms + (ovm_output.ohms * ocm_input.tolerance);
//set output tolerance val
ovm_output.tolerance = ocm_input.tolerance;
}
return(ovm_output);
}
/// <summary>
/// BETA FEATURE: Resistors can have a variable amount of bands, this method converts color band codes to Ohms resistance value.
/// Currently does not account for Fail Rate, nor Temperature Coefficient which is relevant for resistors with color band count greater than 5.
/// </summary>
/// <param name="bandColors">A collection of colors.</param>
/// <param name="resistance"></param>
/// <param name="low"></param>
/// <param name="high"></param>
public void CalculateOhmValue(List <string> bandColors, out decimal resistance, out decimal tolerance, out decimal low, out decimal high)
{
string sigfigs = string.Empty;
resistance = 0;
tolerance = 0;
low = 0;
high = 0;
OhmCalcModel ocm = new OhmCalcModel();
//populate ocm
//single banded resistors only indicate value of resistance with single significant figure
if (bandColors.Count == 1)
{
//populate the list of sigfigs
foreach (var color in bandColors)
{
ocm.significantFigures.Add(_repository.Get(color).SignificantFigure ?? 0);
}
//calculate the actual values.
OhmValuesModel ovm = Utilities.DoCalc(ocm);
resistance = ovm.ohms;
low = (ovm.low ?? 0);
high = (ovm.high ?? 0);
tolerance = (ovm.tolerance ?? 0);
}
//banded resistors are not manufactured with band counts of 2 or greater than 6
else if ((bandColors.Count >= 3) && (bandColors.Count < 6))
{
//the last 2 bands (for resistors with 3 to 5 bands), represent multiplier and tolerance respectively.
ocm.multiplier = (_repository.Get(bandColors[bandColors.Count - 2]).Multiplier ?? 0);
ocm.tolerance = (_repository.Get(bandColors[bandColors.Count - 1]).Tolerance ?? 0);
//now remove the last 2 from List so that just significant figures bands remain
bandColors.RemoveAt(bandColors.Count - 1);
bandColors.RemoveAt(bandColors.Count - 1);
//populate the list of sigfigs
foreach (var color in bandColors)
{
ocm.significantFigures.Add(_repository.Get(color).SignificantFigure ?? 0);
}
//calculate the actual values.
OhmValuesModel ovm = Utilities.DoCalc(ocm);
resistance = ovm.ohms;
low = (ovm.low ?? 0);
high = (ovm.high ?? 0);
tolerance = (ovm.tolerance ?? 0);
}
else if ((bandColors.Count == 6))
{
//band count of 6 currently not supported.
}
}
