[GPlates-discuss] How to check the min and max velocities in GPlates?
Christian.Heine at shell.com
Christian.Heine at shell.com
Thu Jan 28 22:22:25 AEDT 2016
Thanksfor that example, John -- Looking forward to the release (early Feb?)!
Christian
> -----Original Message-----
> From: gplates-discuss-bounces at mailman.sydney.edu.au [mailto:gplates-
> discuss-bounces at mailman.sydney.edu.au] On Behalf Of John Cannon
> Sent: Thursday, 28 January 2016 12:20 PM
> To: GPlates general discussion mailing list
> Subject: Re: [GPlates-discuss] How to check the min and max velocities in
> GPlates?
>
> Actually with the upcoming pygplates release (very soon) there will be a
> way to calculate velocities in dynamic plate polygons (as Simon reminded
> me). But not deforming plates (yet).
>
> To give an idea, the following example calculates velocities of (non-
> deforming) topological plates at static point locations (this will be a
> sample code covered in more detail in the release documentation).
>
>
>
> import pygplates
>
>
> # Load one or more rotation files into a rotation model.
> rotation_model = pygplates.RotationModel('rotations.rot')
>
> # Load the topological plate polygon features.
> topology_features = pygplates.FeatureCollection('dynamic_polygons.gpml')
>
> # Load the features that contain the geometries we will calculate
> velocities at.
> # These can be generated in GPlates via the menu 'Features > Generate
> Velocity Domain Points'.
> velocity_domain_features =
> pygplates.FeatureCollection('lat_lon_velocity_domain_90_180.gpml')
>
> # Calculate velocities using a delta time interval of 1My.
> delta_time = 1
>
> # Our geological times will be from 0Ma to 'num_time_steps' Ma
> (inclusive) in 1 My intervals.
> num_time_steps = 140
>
> # 'time' = 0, 1, 2, ... , 140
> for time in range(num_time_steps + 1):
>
> print 'Time: %d' % time
>
> # All domain points and associated (magnitude, azimuth, inclination)
> velocities for the current time.
> all_domain_points = []
> all_velocities = []
>
> # Partition our velocity domain features into our topological plate
> polygons at the current 'time'.
> partitioned_domain_features = pygplates.partition_into_plates(
> topology_features,
> rotation_model,
> velocity_domain_features,
> reconstruction_time = time)
>
> for partitioned_domain_feature in partitioned_domain_features:
>
> # We need the newly assigned plate ID to get the equivalent stage
> rotation of that tectonic plate.
> partitioning_plate_id =
> partitioned_domain_feature.get_reconstruction_plate_id()
>
> # Get the stage rotation of partitioning plate from 'time +
> delta_time' to 'time'.
> equivalent_stage_rotation = rotation_model.get_rotation(time,
> partitioning_plate_id, time + delta_time)
>
> # A velocity domain feature usually has a single geometry but
> we'll assume it can be any number.
> # Iterate over them all.
> for partitioned_domain_geometry in
> partitioned_domain_feature.get_geometries():
>
> partitioned_domain_points =
> partitioned_domain_geometry.get_points()
>
> # Calculate velocities at the velocity domain geometry
> points.
> # This is from 'time + delta_time' to 'time' on the
> partitioning plate.
> partitioned_domain_velocity_vectors =
> pygplates.calculate_velocities(
> partitioned_domain_points,
> equivalent_stage_rotation,
> delta_time)
>
> # Convert global 3D velocity vectors to local (magnitude,
> azimuth, inclination) tuples (one tuple per point).
> partitioned_domain_velocities =
> pygplates.LocalCartesian.convert_from_geocentric_to_magnitude_azimuth_inc
> lination(
> partitioned_domain_points,
> partitioned_domain_velocity_vectors)
>
> # Append results for the current geometry to the final
> results.
> all_domain_points.extend(partitioned_domain_points)
> all_velocities.extend(partitioned_domain_velocities)
>
>
> > -----Original Message-----
> > From: gplates-discuss-bounces at mailman.sydney.edu.au
> > [mailto:gplates-discuss- bounces at mailman.sydney.edu.au] On Behalf Of
> > John Cannon
> > Sent: Thursday, 28 January 2016 2:52 PM
> > To: GPlates general discussion mailing list
> > Subject: Re: [GPlates-discuss] How to check the min and max velocities
> in GPlates?
> >
> > Hi Nan,
> >
> > > After I open the Kinematics tool (attached snapshot), I clicked the
> > > "velocity magnitude" and
> > did get any response.
> >
> > You also need to select a feature with the Choose Feature tool and
> > then click 'Use focused feature' in the Kinematics Tool dialog.
> >
> > But that gives you the velocities of the selected feature using its
> > plate ID to calculate velocity (actually the velocities of the first
> point in the selected feature I believe).
> > Whereas it looks like you want the traditional velocities of the
> > plates that the static points reside in - which it doesn't calculate.
> Sorry, that all sounds confusing I'm sure.
> >
> > In any case I think you might want the suggestions made by others on
> > this list which essentially boils down to exporting the velocities
> > from GPlates and processing them outside of GPlates.
> >
> > Very soon we will release a GPlates Python library (pygplates) for
> > those familiar with Python programming. The first release of pygplates
> > unfortunately will not calculate the traditional surface velocities
> > (inside dynamic plate boundaries), but the second release will. So, at
> > least for the second release, there will also be the option (in
> > addition to what the others have already suggested) to use Python to
> calculate the velocities (using pygplates library) and then post-process
> them (eg, calculate min/max).
> >
> > Regards,
> > John
> >
> > ________________________________________
> > From: gplates-discuss-bounces at mailman.sydney.edu.au [gplates-discuss-
> > bounces at mailman.sydney.edu.au] on behalf of Nan Zhang
> > [nan.zhang at curtin.edu.au]
> > Sent: Thursday, 28 January 2016 2:21 PM
> > To: GPlates general discussion mailing list
> > Subject: Re: [GPlates-discuss] How to check the min and max velocities
> in GPlates?
> >
> > Hi Christian,
> >
> > After I open the Kinematics tool (attached snapshot), I clicked the
> > "velocity magnitude" and did get any response.
> >
> > When you mentioned "chose GMT (*.xy) as output and then batch process
> > the output files with GMT's "gmt gmtinfo" (formerly minmax).", what is
> > the exact command line for "batch the output files with gmtinfo", given
> my file name velocity_200Ma.xy?
> >
> > I am trying to find the max velocity magnitude for different time
> > frames, because when I put Seton's model to the velocity .gpml file
> > for ASPECT, ASPECT returns me the max velocity at 200Ma is 28 m/yr?
> >
> > Bests,
> > Nan
> >
> >
> >
> > -----Original Message-----
> > From: gplates-discuss-bounces at mailman.sydney.edu.au
> > [mailto:gplates-discuss- bounces at mailman.sydney.edu.au] On Behalf Of
> > Christian.Heine at shell.com
> > Sent: Wednesday, 27 January 2016 10:54 PM
> > To: gplates-discuss at mailman.sydney.edu.au
> > Subject: Re: [GPlates-discuss] How to check the min and max velocities
> in GPlates?
> >
> > Nan,
> >
> > in GPlates: Go to Utilities -> Kinematics tool (or CTRL+k). This is
> > the only place in the GUI where you can directly look at/query
> > velocity information. However, that tool only allows you to use a
> > single feature. If you want to do this for more features and in a more
> > extensive way, you'd have to use the data mining capabilities and
> Python to code up workflows yourself (or even extend this using the Qt
> interface to build a GUI widget).
> >
> > The way Bruce and I suggested earlier will allow you to do a batch
> > analysis of velocity data outside of GPlates. I'd say this is probably
> the fastest and easiest option to get this done.
> > In case that doesn't answer your questions you maybe have to explain
> > in more detail of what you are trying to achieve.
> >
> > Christian (not Christina ;-)
> >
> >
> >
> > > -----Original Message-----
> > > From: gplates-discuss-bounces at mailman.sydney.edu.au [mailto:gplates-
> > > discuss-bounces at mailman.sydney.edu.au] On Behalf Of Nan Zhang
> > > Sent: Wednesday, 27 January 2016 2:50 PM
> > > To: GPlates general discussion mailing list
> > > Subject: Re: [GPlates-discuss] How to check the min and max
> > > velocities in GPlates?
> > >
> > > Hi Sabin, I read through your paper. It is a good paper, while it
> > > does address my issue. My question is how to find a tool in GPlates
> > > interface, to do a statistics for the loaded velocity field (the
> > > max, min, and mean velocity magnitude). Besides Christina's
> > > suggestion early on, is there a direct tool in GPlates?
> > >
> > >
> > >
> > >
> > >
> > > ________________________________
> > >
> > > From: gplates-discuss-bounces at mailman.sydney.edu.au
> > > <gplates-discuss- bounces at mailman.sydney.edu.au> on behalf of Sabin
> > > Zahirovic <sabin.zahirovic at sydney.edu.au>
> > > Sent: Wednesday, 27 January 2016 4:28 PM
> > > To: GPlates general discussion mailing list
> > > Subject: Re: [GPlates-discuss] How to check the min and max
> > > velocities in GPlates?
> > >
> > > Hi Nan,
> > >
> > > Please check this paper that talks about all of these things:
> > > http://www.earthbyte.org/tectonic-speed-limits-from-plate-kinematic-
> > > reconstructions/
> > >
> > > <http://www.earthbyte.org/tectonic-speed-limits-from-plate-kinematic
> > > -
> > > reconstructions>
> > > Tectonic speed limits from plate kinematic reconstructions ...
> > > <http://www.earthbyte.org/tectonic-speed-limits-from-plate-kinematic
> > > -
> > > reconstructions>
> > > www.earthbyte.org
> > > Citation Zahirovic, S., Müller, R. D., Seton, M., & Flament, N.
> (2015).
> > > Tectonic speed limits from plate kinematic reconstructions. Earth
> > > and Planetary Science ...
> > >
> > > http://www.sciencedirect.com/science/article/pii/S0012821X15001235
> > >
> > > Hope that helps!
> > >
> > > Cheers,
> > > Sabin
> > >
> > >
> > > --
> > >
> > > DR SABIN ZAHIROVIC | Postdoctoral Research Associate School of
> > > Geosciences | Faculty of Science
> > >
> > >
> > > THE UNIVERSITY OF SYDNEY
> > > Rm 403, Madsen Building F09 | The University of Sydney | NSW | 2006
> > > M
> > > +61
> > > 416 775 589 P +61 2 9351 3625 E sabin.zahirovic at sydney.edu.au | W
> > > http://www.earthbyte.org <http://www.earthbyte.org/> | R
> > > http://www.researchgate.net/profile/Sabin_Zahirovic
> > > <http://www.researchgate.net/profile/Sabin_Zahirovic>
> > > F https://www.facebook.com/earthbyte | T
> > > https://twitter.com/EarthByteGroup
> > >
> > > CRICOS 00026A
> > > This email plus any attachments to it are confidential. Any
> > > unauthorised use is strictly prohibited. If you receive this email
> > > in error, please delete it and any attachments.
> > >
> > > From: <gplates-discuss-bounces at mailman.sydney.edu.au> on behalf of
> > > Nan Zhang <nan.zhang at curtin.edu.au>
> > > Reply-To: GPlates general discussion mailing list <gplates-
> > > discuss at mailman.sydney.edu.au>
> > > Date: Wednesday, 27 January 2016 at 7:13 PM
> > > To: "gplates-discuss at mailman.sydney.edu.au" <gplates-
> > > discuss at mailman.sydney.edu.au>
> > > Subject: [GPlates-discuss] How to check the min and max velocities
> > > in GPlates?
> > >
> > >
> > >
> > > Hi all,
> > >
> > >
> > >
> > > I loaded Seton et al., 2012 data to generate some plate velocity
> > > files from 200Ma to the present day. One thing I want to check is
> > > the minimum and maximum velocity magnitudes. Who can give me some
> instruction?
> > >
> > >
> > >
> > > Bests,
> > >
> > > Nan
> >
> > _______________________________________________
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