Added time dependant transformation function (DOESNT WORK YET)

Author: Kyran-Cook

geodepy/transform.py

@@ -15,11 +15,13 @@
 from math import radians
 import numpy as np
 from geodepy.constants import (Transformation, TransformationSD,
-                               atrf2014_to_gda2020, gda94_to_gda2020)
+                               atrf2014_to_gda2020, gda94_to_gda2020,
+                               itrf2014_to_gda2020, itrf2014_to_itrf2005)
 from geodepy.statistics import vcv_local2cart, vcv_cart2local
 from geodepy.convert import (hp2dec, geo2grid,
                              grid2geo, xyz2llh, llh2xyz)
 from geodepy.ntv2reader import NTv2Grid, interpolate_ntv2
+from dateutil.relativedelta import relativedelta
 
 
 def conform7(x, y, z, trans, vcv=None):
@@ -147,6 +149,65 @@ def conform14(x, y, z, to_epoch, trans, vcv=None):
     xtrans, ytrans, ztrans, trans_vcv = conform7(x, y, z, timetrans, vcv=vcv)
     return xtrans, ytrans, ztrans, trans_vcv
 
+def time_dep_transformation_aus(x, y, z, from_epoch, to_epoch, trans, plate_motion=itrf2014_to_gda2020, vcv=None):
+    """
+    Preforms time dependant transformations using a Helmert 14 Conformal Transformation and a plate motion model.
+    Performs a Helmert 14 Parameter Conformal Transformation using Cartesian point co-ordinates
+    and a predefined transformation object. The transformation parameters are projected from
+    the transformation objects reference epoch to a specified epoch.
+
+    :param x: Cartesian X (m)
+    :param y: Cartesian Y (m)
+    :param z: Cartesian Z (m)
+    :param from_epoch: Epoch co-ordinate transformation is from (datetime.date Object)
+    :param to_epoch: Epoch co-ordinate transformation is to (datetime.date Object)
+    :param trans: Transformation Object
+    :param plat_motion: Plate motion model for transformation (defaults to australian plate motion)
+    :param vcv: Optional 3*3 numpy array in Cartesian units to propagate tf uncertainty
+    :return: Cartesian X, Y, Z co-ordinates and vcv matrix transformed using Transformation parameters at desired epoch
+    """
+    if type(trans) != Transformation:
+        raise ValueError("trans must be a Transformation Object")
+    if type(to_epoch) != datetime.date:
+        raise ValueError("to_epoch must be a datetime.date Object")
+    if type(from_epoch) != datetime.date:
+        raise ValueError("from_epoch must be a datetime.date Object")
+    if type(plate_motion) != Transformation:
+        raise ValueError("plate_motion must be a Transformation Object")
+       
+
+    if from_epoch == trans.ref_epoch:
+
+        print("The from Epoch was correct!")
+        # Calculate 7 Parameters from 14 Parameter Transformation Object
+        timetrans = trans + to_epoch
+
+        # Perform Transformation
+        xtrans, ytrans, ztrans, trans_vcv = conform7(x, y, z, timetrans, vcv=vcv)
+        return xtrans, ytrans, ztrans, trans_vcv
+    else:
+        # Step 1: Transform coordinates to ref_epoch
+        # Find time difference
+        timediff = relativedelta(from_epoch, trans.ref_epoch)
+        #timediff = trans.ref_epoch - from_epoch
+        plate_to_epoch = plate_motion.ref_epoch + timediff
+        print(f"Step 1 epoch: {timediff}")
+        # Complete conform14 with plate motion
+        x, y, z, vcv = conform14(x, y, z, plate_to_epoch, plate_motion, vcv)
+
+        # Step 2: Complete transformation
+        x, y, z, vcv = conform7(x, y, z, trans, vcv)
+
+        # Step 3: Transform coordinates to to_epoch
+        # Find time difference
+        timediff = relativedelta(to_epoch, trans.ref_epoch) #+ datetime.timedelta(days=1)
+        print(f"Step 2 diff: {timediff}")
+        plate_to_epoch = plate_motion.ref_epoch + timediff
+
+        # Complete conform14 with plate motion
+        return conform14(x, y, z, plate_to_epoch, plate_motion, vcv)
+
+print(time_dep_transformation(-4052042.7920922847, 4212825.645301947, -2545098.301585565, datetime.date(2000, 1, 1), datetime.date(2020, 1 ,1), itrf2014_to_itrf2005))
 
 def transform_mga94_to_mga2020(zone, east, north, ell_ht=False, vcv=None):
     """