spatialvxericg/talks/gillelandspatialvxtalk... · 2016. 9. 23. · band-pass filtering / scale...
TRANSCRIPT
SpatialVx
Eric Gilleland Weather Systems Assessment Program
Research Applications Laboratory
2016 MesoVICT Workshop Wednesday, 21 September 2016
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SpatialVx
http://www.ral.ucar.edu/projects/icp/SpatialVx/ http://www.r-project.org
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SpatialVx
Name Description Functions Notes Tested Field Significane
Simulation-based field significance testing
spatbiasFS, LocSig,MCdof
Contributed by Kim Elmore
?
Spatial Prediction Comparison Test (SPCT)
Hypothesis test (CI’s) for competing forecasts that accounts for spatial dependence
spctlossdiffempiricalVG.lossdiffflossdiffsummary
Assistance from Amanda Hering
Yes
Significance Testing
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SpatialVx Significance Testing
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SpatialVx
Name Description Functions Notes Tested Fractions Skill Score (FSS)
Compares event frequencies within neighborhoods
hoods2d Makes use of fft from R package stats.
Yes
Most other neighborhood methods
see Ebert (2008, Meteorol. Appl., 15, 51 - 64. DOI: 10.1002/met.25)
hoods2dpphindcast2dupscale2d
Some
Wavelet de-noising Smoothing by way of wavelet denoising
wavePurifyVx Uses waveslim package by Brandon Whitcher
Yes
Low-pass Filtering / Neighborhood Methods
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SpatialVx
Name Description Functions Notes Tested Intensity Scale (IS), Wavelet Details
Summary measures of wavelet detail fields
waveISwaverify2d
Uses waveslim package
Some
Structure Function Variability/structure at different spatial lags
structurogramstructurogram.matrixvariogram.matrix
Heavy copying of vgram.matrix from fields package by Doug Nychka et al.
Some
Band-pass Filtering / Scale Separation
Very good, recent review paper about wavelet spatial verification methods (+ a new proposed technique): Weniger, M., F. Kapp, and P. Friederichs, 2016: Spatial Verification Using Wavelet Transforms: A Review. arXiv preprint arXiv:1605.03395
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SpatialVx
Name Description Functions Notes Tested Binary Image Metrics
Distance map based summary measures
locmeasures2dlocperf
Uses distmap, deltametric, and other functions from R package spatstat.
Some
Forecast Quality Index (FQI)
Image metric that accounts for intensity differences as well as displacmeents
FQI No
Displacement measures
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SpatialVx
Name Description Functions Notes Tested Zhu’s metric linear combination of
two measures: (i) the amount of overlap between events in two fields and (ii) the mean error distance
metrV Yes
Image Moments Summary information for an object or field, e.g. centroid, orientation angle, etc.
imomenter Yes
Displacement measures (continued)
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SpatialVx
Name Description Functions Notes Tested Optical Flow (OF) Deform forecast
using gradients OF Contributed
by Caren Marzban
No
Rigid transformation
Deform forecast using translations and/or rotations only
rigiderrigidTransform
Needs more
Field Displacement
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SpatialVx Name Functions Notes Tested Identify Features FeatureFinder Uses
connected function from R package spatstat
Yes
Merge/Match Features
centmatchminboundmatchdeltammMergeForce
Some
Analyzing Features
FeatureMatchAnalyzerFeatureAxisFeaturePropsFeatureCompsFeatureTable
Some
Feature-based
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SpatialVx Name Description Functions Notes Tested Cluster Analysis Use statistical
cluster analysis to define features
clustererCSIsamples
CSIsamples contributed by Caren Marzban
Some and ?
Contiguous Rain Area (CRA)
Use rigid transformation and breakdown RMSE
craer No
Structure Amplitude Location (SAL)
Distributional comparisons of identified features
saller Some
Composite Distributions of features
compositer No
Shape Analysis Reduce features to landmark points describing their shape
hiwdistillsummary
Obtains landmarks (tricky) for use with shapes package
Yes, but …
Feature-based (cont.)
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SpatialVx Feature-based
X (feature 1) Xhat (feature 1)
Observed Feature
Forecast Feature
Shape Analysis
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SpatialVx
Name Description Functions Notes Tested Method for Object-based Diagnostic Evaluation (MODE)
MODE-type analysis interester Minimal
Feature-based (cont.)
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Name Description Functions Notes Tested Geometric Indices
Summarizes shapes and texture within a field
Cindex, Sindex and Aindex
Yes
SpatialVx
Field Patterns / Texture
Aindex and Sindex useful for single objects too. See also variogram and variogram.matrix for analyzing field texture. New wavelet method, but not in SpatialVx (so far!)
AghaKouchak et al. (2011, doi:10.1175/2010JHM1298.1)
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SpatialVx Name Description Functions Notes Tested Anomaly Correlation Coefficient
Correlation using a climatology instead of the mean
ACC Some
Bias-adjusted Gilbert Skill Score
Accounts for spatial bias
vxstats Some
Gaussian Mixture Models (GMM)
Fitted parameters inform about displacement errors
gmm2d Very Slow
Yes
Geographic box plot
Box plots that account for grid box area differences
GeoBoxPlot Yes
S1 score Comparison of gradients between two fields
S1 No
Miscellaneous
New User’s Group
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https://www.linkedin.com/groups/8550343
Future Plans • Finish/Start Testing all functions • Get all functions in-line with general
methods for functions • Methods Needing to be Added
§ Image Warping § Optical Flow/DAS (Keil and Craig) § Newly Proposed Methods § New modifications of FSS § Other?
• Write a tutorial
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Questions?
Thank you to those who have been testing functions from the package. It is nice to have the help! It is always appreciated to have bugs and other errors identified
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