public override _1DCrossSectionGeometricProperties GetCrossSectionPropertiesAt(double xi)
{
if (sectionAtStart.Length != sectionAtEnd.Length)
{
throw new InvalidOperationException();
}
var n = sectionAtStart.Length;
var target = new PointYZ[n];
var s1 = (1.0 - xi) / 2.0;
var s2 = (1.0 + xi) / 2.0;
for (var i = 0; i < n; i++)
{
var pt = new PointYZ();
pt.Y = sectionAtStart[i].Y * s1 + sectionAtEnd[i].Y * s2;
pt.Z = sectionAtStart[i].Z * s1 + sectionAtEnd[i].Z * s2;
target[i] = pt;
}
var _geometry = target;
return(_1DCrossSectionGeometricProperties.Calculate(target, this._resetCentroid));
}
public override _1DCrossSectionGeometricProperties GetCrossSectionPropertiesAt(double xi)
{
var target = new _1DCrossSectionGeometricProperties();
var s1 = sectionAtStart;
var s2 = sectionAtStart;
{
var f1 = (1.0 - xi) / 2.0;
var f2 = (1.0 + xi) / 2.0;
var pt = new PointYZ();
target.A = s1.A * f1 + s2.A * f2;
target.Ay = s1.Ay * f1 + s2.Ay * f2;
target.Az = s1.Az * f1 + s2.Az * f2;
target.J = s1.J * f1 + s2.J * f2;
target.Iy = s1.Iy * f1 + s2.Iy * f2;
target.Iz = s1.Iz * f1 + s2.Iz * f2;
}
return(target);
}
public override _1DCrossSectionGeometricProperties GetCrossSectionPropertiesAt(double xi)
{
if (sectionAtStart.Length != sectionAtEnd.Length)
{
throw new InvalidOperationException();
}
var n = sectionAtStart.Length;
var target = new PointYZ[n];
var s1 = (1.0 - xi) / 2.0;
var s2 = (1.0 + xi) / 2.0;
for (var i = 0; i < n; i++)
{
var pt = new PointYZ();
pt.Y = sectionAtStart[i].Y * s1 + sectionAtEnd[i].Y * s2;
pt.Z = sectionAtStart[i].Z * s1 + sectionAtEnd[i].Z * s2;
target[i] = pt;
}
var _geometry = target;
var buf = new _1DCrossSectionGeometricProperties();
{
var lastPoint = _geometry[_geometry.Length - 1];
if (lastPoint != _geometry[0])
{
throw new InvalidOperationException("First point and last point ot PolygonYz should put on each other");
}
double a = 0.0, iz = 0.0, iy = 0.0, ixy = 0.0;
var x = new double[_geometry.Length];
var y = new double[_geometry.Length];
for (int i = 0; i < _geometry.Length; i++)
{
x[i] = _geometry[i].Y;
y[i] = _geometry[i].Z;
}
var l = _geometry.Length - 1;
var ai = 0.0;
for (var i = 0; i < l; i++)
{
ai = x[i] * y[i + 1] - x[i + 1] * y[i];
a += ai;
iy += (y[i] * y[i] + y[i] * y[i + 1] + y[i + 1] * y[i + 1]) * ai;
iz += (x[i] * x[i] + x[i] * x[i + 1] + x[i + 1] * x[i + 1]) * ai;
ixy += (x[i] * y[i + 1] + 2 * x[i] * y[i] + 2 * x[i + 1] * y[i + 1] + x[i + 1] * y[i]) * ai;
}
a = a * 0.5;
iz = iz * 1 / 12.0;
iy = iy * 1 / 12.0;
ixy = ixy * 1 / 24.0;
var j = iy + iz;
//not sure which one is correct j = ix + iy or j = ixy >:)~
buf.A = Math.Abs(a);
buf.Iz = Math.Abs(iz);
buf.Iy = Math.Abs(iy);
buf.J = Math.Abs(j);
buf.Ay = Math.Abs(a); //TODO: Ay is not equal to A, this is temporary fix
buf.Az = Math.Abs(a); //TODO: Az is not equal to A, this is temporary fix
}
return(buf);
}
