public static GaFrame CreateOrthonormal(IEnumerable <char> frameSigSignList)
{
var psgCount = 0;
var nsgCount = 0;
var s = new StringBuilder();
var sigList = new List <int>(FrameUtils.MaxVSpaceDimension);
//Convert the string signature into a list of integers with values of 1 and -1.
foreach (var c in frameSigSignList)
{
switch (c)
{
case '+':
sigList.Add(1);
s.Append("+");
psgCount++;
break;
case '-':
sigList.Add(-1);
s.Append("-");
nsgCount++;
break;
default:
throw new GMacSymbolicException("Invalid orthonormal frame signature");
}
}
var vSpaceDim = psgCount + nsgCount;
VerifyVSpaceDim(vSpaceDim);
var frameSig = s.ToString();
GaFrame gaFrame;
if (OrthonormalFramesCache.TryGetValue(frameSig, out gaFrame))
{
return(gaFrame);
}
//The frame signature has no vectors with negative signature; create a Euclidean frame
if (nsgCount == 0)
{
gaFrame = new GaFrameEuclidean(vSpaceDim);
}
//Else create an orthonormal frame
else
{
gaFrame = new GaFrameOrthonormal(sigList.ToArray());
}
OrthonormalFramesCache.Add(frameSig, gaFrame);
return(gaFrame);
}
public static GaFrameEuclidean CreateEuclidean(int vSpaceDim)
{
VerifyVSpaceDim(vSpaceDim);
GaFrame gaFrame;
var frameSig = GetOrthonormalSignatureString(vSpaceDim);
if (OrthonormalFramesCache.TryGetValue(frameSig, out gaFrame))
{
return((GaFrameEuclidean)gaFrame);
}
gaFrame = new GaFrameEuclidean(vSpaceDim);
OrthonormalFramesCache.Add(frameSig, gaFrame);
return((GaFrameEuclidean)gaFrame);
}