Utilities

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Time Series Analysis

filter1d.m

Filter1D: Time Series Analysis Tool

  • The Matlab utility provides users of the SMS, a one-stop package for preparing model input time series and allows users to interpolate, resample, filter, and transform any type of model forcing and supports SMS compatible file formats for ease of data transfer.
  • The main feature of the software is the ability to apply high-pass, low-pass, band-pass, and band-stop filters to time series.
  • Filter1D uses a windowed sinc filter which is a non-recursive finite impulse response filter.
  • Wiki Manual Filter1d
  • Download Matlab script filter1d.m


TAP Interface

TAP: Tidal Analysis and Prediction software

    • TAPtides is the ideal package to explore and develop preliminary or finalized tidal predictions from serial records spanning several weeks to several months.
    • Designed to be easy to use, its Graphical User Interface permits quick separation of a time series of water level measurements into its tidal and non-tidal components using a selective least squares harmonic reduction employing up to 35 tidal constituents.
    • After saving the tidal constants for the constituents selected during analysis, the user can generate predictions of the astronomical tide, the water level that varies at known tidal frequencies attributable to gravitational interactions between the earth, moon, and sun.
  • Wiki Manual for TAPtides TAPtides
  • Wiki Manual for TAPcurrents TAPcurrents
  • Download software TAP.rar


Post-processing

Matlab scripts

Read CMS-Flow Grid File (*_grid.h5)

  • Description: Reads a CMS grid file and creates a structure variable containing the grid datasets values
  • Input:
filename - input file name including full path
varargin - dataset names
  • Output:
grd - structure variable containing dataset values and times
varargout - variable datasets corresponding to varargin
  • Usage:

sol = readcmsgrid(filename,...'dataset1','dataset2',...)
grd = readcmsgrid('test_grid.h5');
x = readcmsgrid(filename,'x');
[x,y] = readcmsgrid(filename,'x','y');


Read CMS-Flow Tel File (*.tel)

  • Description: Reads a CMS telescoping grid file and creates a structure variable containing the grid information.
  • Input:
filename - input file name including full path
  • Output:
tel - structure variable containing datasets
  • Usage:

tel= readcmstel('Flow_test.tel');


Read CMS-Flow solution files

  • Description: Reads the CMS-Flow XMDF (*.h5) solution file in Matlab. Can read individual datasets are the whole solution.
  • Usage:

filename = 'test_sol.h5';
sol = readcmsh5(filename);
wse = readcmsh5(filename,'Water_Elevation');
[wse,uv] = readcmsh5(filename,'Water_Elevation','Current_Velocity');


Read SMS Time Series Data File

  • Description: Reads the Surface-water Modeling System time-series data (*.tsd) file.
  • Usage:

[t,dat,name,units] = read_tsd('data.tsd');


Write SMS Time Series Data File

  • Description: Writes a Surface-water Modeling System time-series data (*.tsd) file.
  • Usage:

 write_tsd(filenamet,dat,curvename,curvetype);


Read SMS XY Series File

  • Description: Reads the Surface-water Modeling System xy series (*.xys) file.
  • Usage:

[x,y,name] = read_xys('data.xys');


Bin scatter data

Example of xyzbin.m application to multibeam data with 5-m bins.
  • Description: Averages the x, y, and z values of points within the same bin. The grid used to define the bins may be user specified are calculated based on the extent of the scatter points.
  • Usage:

[x,y,z] = xyzbin(...);
[x,y,z] = xyzbin('infile',infile,'outfile',outfile,'dx',dx);
[x,y,z] = xyzbin('x',xin,'y',yin,'z',zin,'dx',dx);
[x,y,z] = xyzbin('x',xin,'y',yin,'z',zin,'dx',dx,'dy',dy);
[x,y,z] = xyzbin('infile',infile,'dx',dx,'x0',x0,'y0',y0,'theta',theta);


Interpolation of CMS-Wave Spectra

  • Description: Interpolates the energy spectra in the CMS-Wave *.eng file to a specified output interval which may be specified in intervals or time units (hours). For example, an output interval of 0.5 index units, interpolates the spectra at half intervals. This subroutine is useful for filling small gaps in CMS spectra.
  • Usage:

interp_eng('Wave.eng','New.eng',1,0.5) %interpolates to every half interval
interp_eng('Wave.eng','New.eng',1,2)   %resamples every two spectra
interp_eng('Wave.eng','New.eng',2,1)   %hrs


Principle Component Analysis of Vector Time Series

Example of a principle component analysis.
  • Description: Calculates the principle axes of vector time series data. This subroutine is useful for determining the main direction of fluid flow and extracting the velocity component along the major axis. The principle axes are determined by solving the eigenvalue problem for two-dimensional scatter data.
  • Usage:

s = uv2ellipse(u,v);
s = uv2ellipse(u,v,show);  %show=1 - Plots results
s = uv2ellipse(u,v,show,pos); %pos - displays a table on figure with results at pos=(x,y)

  • Output:
s = Structure with the following fields:
area = Area del ellipse
axes = Magnitude of ellipse axes [major, minor];
vartotal = Total variance
Percentages = Percentage variance for each axes
Angles = Angles for each axes in degrees [major, minor];
excen = Excentricity of the ellipse
ellipse = Points [x,y] which describe the ellipse
Slope = Slope of the linear fit which goes through the origin
Center = Center of the ellipse [cu,cv]
  • Note: An alternative simple way of determining the principle axes of vector time series is

\begin{equation} \tag{1} 

 \phi_p  = \frac{1}{2} \arctan ^{-1} \biggl( \frac{2 \big\langle u v \big\rangle }{ \big\langle v^2 \big\rangle - \big\langle u^2 \big\rangle } \biggr) + \frac{\pi}{2}

\end{equation}


Spectral Analysis

Example of Power Spectrum for an idealized water level time series with white noise and a large gap.
  • Description: Calculates the spectrum for a scalar time series using Welch's method. The confidence intervals are calculated with the inverse of chi-square distribution. Also includes a filtering option using the butterworth filter to see the effect of the filter on the spectrum.
  • Usage:

q = specwelch(x,dt,w,Nsg,pnv,Wn,ftype,n);
[psdf,f] = specwelch(x,dt,w,Nsg,pnv,Wn,ftype,n);
[psdf,conf,f] = specwelch(x,dt,w,Nsg,pnv,Wn,ftype,n);

  • Input:
x - Time series, [vector]
dt - Sampling Rate, [scalar]
win - Window, one of: 'hanning', 'hamming', 'boxcar'
Nsg - Number of Segments (>=1)
pnv - Percentage Noverlap of Segments (0-100)
Nb - Band Averaging, number of bands to average
P - Probability for confidence intervals, (e.g. 0.95)
Wn - Cut-Off frequencies, used for filtering
ftype - Type of filter, 'high', 'low' or 'stop'
n - Number of coefficients to use in the Butterworth filter
  • Output:
q - structure with the following fields:
xp - detrended x
f - Frequencies
T - Periods
m - Magnitude
a - Amplitude
s - Power spectrum, Sxx(win), [Power]
psdw - Power Spectrum Density, Pxx(win), [Power/rad/sample]
psdf - Power Spectrum Density, Pxx(f), [Power/sample-freq]
psdT - Power Spectrum Density, Pxx(T), [Power*time-unit]
conf - Upper and Lower Confidence Interval multiplication factors using chi-squared approach

Vector Plot

Example comparisons between feater.m, quiver.m, and vecplot.m
  • Description: Plots directionally correct vectors. Both of matlab subroutines feather.m and quiver.m do not preserve the correct vctor angles.
  • Usage:

h = vecplot(x,y,u,v,'PropertyName',PropertyValue,...)
h = vecplot(u,v,'PropertyName',PropertyValue,...)

  • Input:
x,y = Position Coordinates
u,v = Vector Componentes
  • Optional Properties
'DataAspectRatio' = Scaling factor between x and y axes. This is set as the second element of the property 'DataAspectRatio'
'LengthScale' = Length scaling factor for the barbs or arrows
'LineSpec' = Line specification string syntax (default '-k^') (e.g. '^k' - plots black arrows, 'k' - plots black sticks)
'Linewidth' = Linewidth
'Marker' = '^' for triangle arrows, 'v' for angled arrows,
and for stick plots (default stick)
'MarkerFaceColor' = Arrow fill color (default none)
'MarkerEdgeColor' = Arrow edge color (default line color)
'MarkerSize' = Marker size
'LegendLength' = Sets the length of the legend vector
'LegendUnits' = Sets the units for the legend vector
'legendPosition' = Sets the legend position (normalized units 0-1)
  • Output:
h = handles for plot objects


Example using vecplot to plot wave conditions.


Extract Time Series from NOAA World Blended Sea Winds

Blended Surface Sea Winds for a section of the North-West US coast.
Extracted sea winds
Extracted sea winds


x,y = Position Coordinates
u,v = Vector Componentes
  • Output:
h = handles for plot objects


Image Digitization Tool

Example digitization of an earthquake rupture zone.
  • Description: digitize is a user interfase that allows to import image files (.bmp, etc) into MatLab to digitize data from. Previous sessions can also be loaded. It is useful for digitizing plots%and making world files for images. The utility can be used for digitizing time series plots, geographic features such as coastlines, or elevation contours.
  • Instructions:
  • Load image
  1. To start a new session, click on the "Load" menu and select "Image File".
  2. To load a saved session, click on the "Load" menu and select "Session".
  • Reference the image
  1. Click on the "Transformation" menu and select "Add Points".
  2. Left-click on the points reference points and Right-click when finished.
  3. Right-click on any reference point and select "Reference" to enter the points "true" coordinate.
  4. When the coordinated for all the reference points have been entered the "Reference Data Complete" item under the "Transformation" menu will be checked.
  5. To delete Transformation points, right-click on a point and select "Delete".
  • Digitize Points
  1. Click on the "Digitization" menu and select "Add Points". The digitized points may be entered at any time, but their transformed coordinated are not calculated until the reference data is complete.
  2. To see a digitized point's transformed coordinate, right-click on a point and select "Coordinates".
  • Export the Digitized Points
  1. Click on "Export" and select one of the output options including variables to the workspace and an ASCII file.


Create Spectra Generation Import file with WIS datafiles

  • Description: This function creates the .txt file used in the spectra generator of CMS Wave. It prompts the user to select all the desired WIS output files, specify the depth of the station, and whether or not to average the data series. The data and user inputs are manipulated into the format used by CMS Wave file import for spectra generation. Currently the output file is saved in the active directory of matlab.
  • Usage: Type mfile name in Matlab command window

CMS_WIS_to_txt_for_spectragen


Read an SMS Super ASCII data file (*.dat)

  • Description: This function reads an SMS Super ASCII data file (*.dat). These files are part of the SMS Super ASCII format and is an output option for global solution datasets in CMS. The SMS Super ASCII format also includes a coordinates file (*.xy) and a super file (*.sup) which contains the names of the coordinate file and dataset files.
  • Usage:

[t,x] = readsuperdat(filename);


Read an SMS xy file (*.xy)

  • Description: This function reads an SMS xy file (*.xy). These files are used in the SMS Super ASCII in conjuction with the by CMS as an ASCII output option for global solution datasets. The SMS Super ASCII format also includes dataset files (*.dat) and a super file (*.sup) which contains the names of the coordinate file and dataset files.
  • Usage:

[t,x] = read_xy(filename);


TextPad Syntax File for CMS-Flow Card File

Example cmcards file viewed in Textpad
  • Color codes the CMS-Flow card file (*.cmcards) so that it is easier to read and avoids misspelling of keywords.
  • To setup the file:
  1. Open Textpad and click on the menu Configure and go to Preferences.
  2. Click on folder on the left hand side and note the path to the syntax files.
  3. Copy-paste the .syn to the path noted in step 2.
  4. Click on Configure | New Class Document.
  5. Enter CMS-Flow as the document name and click next.
  6. Enter *.cmcards in Class members and click next.
  7. Enable the syntax highlighting and select the CMS-Flow_V4.syn file.
  8. Click on Finish and your done!


HDFview

  • HDFview is a free visualziation tool for browsing and editing HDF4 and HDF5 files.
  • To download or download a free copy visit:
http://www.hdfgroup.org/hdf-java-html/hdfview/

Grain Size Distribution Analysis

  • This Excel worksheet calculates statistics for many samples using several methods including Folk and Ward and the Method of Moments.
http://www.cedex.es/pipermail/rivers-list/attachments/20061004/56b4085f/gradistat-0001.xls


Wave Transformation

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