Add hpval

same inputs as `hval`

pytspack/__init__.py

@@ -54,6 +54,37 @@ def hval(xp, x, y, yp, sigma):
  return y_out
 
 
+def hpval(xp, x, y, yp, sigma):
+ """Function which evaluates the first derivative of a Hermite
+ interpolatory tension spline ("HP") at points `xp`.
+
+ Parameters
+ ----------
+ xp : array_like
+ New X points at which HP is to be evaluated.
+ x : array_like
+ Original X points (abscissae).
+ y : array_like
+ Data values at the original X points.
+ yp : array_like
+ First derivatives of Y at original X points. HP(X(I)) = YP(I).
+ sigma : array_like
+ Tension factors, for each interval in the original X points
+ (as such, length N - 1).
+
+ Returns
+ -------
+ list of float
+ HP values.
+ """
+ xp = array(xp)
+ x = array(x)
+ y = array(y)
+ sigma = array(sigma)
+ yp_out = [tspack.hpval(xi, x, y, yp, sigma, 1) for xi in xp]
+ return yp_out
+
+
 def tspsi(x, y, ncd=1, slopes=None, curvs=None, per=0, tension=None):
  """Subroutine which constructs a shape-preserving or
  unconstrained interpolatory function. Refer to