public static Vector128 <float> GetFlewellingGrowthEffectiveAge(SiteConstants site, float timeStepInYears, Vector128 <float> treeHeight, out Vector128 <float> potentialHeightGrowth)
{
// for now, just a vector to scalar shim for caller convenience
// TODO: SIMD implementation
float growthEffectiveAge0 = WesternHemlock.GetFlewellingGrowthEffectiveAge(site, timeStepInYears, Avx.Extract(treeHeight, 0), out float potentialHeightGrowth0);
float growthEffectiveAge1 = WesternHemlock.GetFlewellingGrowthEffectiveAge(site, timeStepInYears, Avx.Extract(treeHeight, 0), out float potentialHeightGrowth1);
float growthEffectiveAge2 = WesternHemlock.GetFlewellingGrowthEffectiveAge(site, timeStepInYears, Avx.Extract(treeHeight, 0), out float potentialHeightGrowth2);
float growthEffectiveAge3 = WesternHemlock.GetFlewellingGrowthEffectiveAge(site, timeStepInYears, Avx.Extract(treeHeight, 0), out float potentialHeightGrowth3);
potentialHeightGrowth = Vector128.Create(potentialHeightGrowth0, potentialHeightGrowth1, potentialHeightGrowth2, potentialHeightGrowth3);
Vector128 <float> growthEffectiveAge = Vector128.Create(growthEffectiveAge0, growthEffectiveAge1, growthEffectiveAge2, growthEffectiveAge3);
return(growthEffectiveAge);
}
/// <summary>
/// Calculate western hemlock growth effective age and potential height growth using Flewelling's model for dominant individuals.
/// </summary>
/// <param name="site">Site growth constants.</param>
/// <param name="treeHeight">Height of tree.</param>
/// <param name="timeStepInYears"></param>
/// <param name="growthEffectiveAge">Growth effective age of tree.</param>
/// <param name="potentialHeightGrowth">Potential height growth increment in feet.</param>
public static float GetFlewellingGrowthEffectiveAge(SiteConstants site, float timeStepInYears, float treeHeight, out float potentialHeightGrowth)
{
// For Western Hemlock compute Growth Effective Age and 5-year potential
// or 1-year height growth using the western hemlock top height curves of
// Flewelling.These subroutines are required:
// SITECV_F computes top height from site and age
// SITEF_C computes model parameters
// SITEF_SI calculates an approximate psi for a given site
// Note: Flewelling's curves are metric.
// Site Index is not adjusted for stump height.
float HTM = Constant.MetersPerFoot * treeHeight;
// find growth effective age within precision of 0.01 years
float HTOP;
float AGE = 1.0F;
float growthEffectiveAge;
for (int index = 0; index < 4; ++index)
{
do
{
AGE += 100.0F / MathV.Exp10(index);
if (AGE > 500.0F)
{
growthEffectiveAge = 500.0F;
WesternHemlock.SITECV_F(site, growthEffectiveAge, out float XHTOP1);
WesternHemlock.SITECV_F(site, growthEffectiveAge + timeStepInYears, out float XHTOP2);
potentialHeightGrowth = Constant.FeetPerMeter * (XHTOP2 - XHTOP1);
return(growthEffectiveAge);
}
WesternHemlock.SITECV_F(site, AGE, out HTOP);
}while (HTOP < HTM);
AGE -= 100.0F / MathV.Exp10(index);
}
growthEffectiveAge = AGE;
// Compute top height and potential height growth
WesternHemlock.SITECV_F(site, growthEffectiveAge + timeStepInYears, out HTOP);
float potentialTopHeightInFeet = Constant.FeetPerMeter * HTOP;
potentialHeightGrowth = potentialTopHeightInFeet - treeHeight;
return(growthEffectiveAge);
}
