Exporting to MATLAB

Echoview supports the export of data to MATLAB format files (*.mat) for the following data types:

• Single beam
  • Power dB
  • Sv
  • TS
  • Unspecified dB
  • Angular position
• Wideband (complex)
  • Complex power dB
  • Complex Sv
  • Complex TS
  • Complex angular position
• Wideband (pulse-compressed complex)
  • Pulse compressed complex power dB
  • Pulse compressed complex Sv
  • Pulse compressed complex TS
  • Pulse compressed complex angular position
• Multibeam
  • Multibeam magnitude (beamformed)
  • Multibeam Sv
  • Multibeam TS
  • Multibeam unspecified dB

Notes:

• The longitude and latitude values that are exported are the longitude and latitude of the GPS antenna at the time the ping was transmitted, see What is affected by transducer geometry for more information.
• From Echoview 13 onwards, exports from complex variables output real and imaginary values. The complex data export to MATLAB export is not available to regions or selections.
  Prior to Echoview 13, exports from complex variables output single dB values per sample as displayed in echograms. See also: Complex data exports (where every sample is represented by a real and an imaginary number).
• Complex export availability depends on the operand.
  • Operands such as complex Sv, TS, power dB, and pulse-compressed complex variants can export to .mat or .complex.mat.
  • Other operands (e.g., angular position, complex angular position, multibeam magnitude) export to .mat only. If a .complex.mat file name is supplied for these, the file is saved as .mat and a message explains why.
• Corrupted files may be created if the resulting MATLAB file is 2 GB or greater. If this occurs, please use fewer pings per export.
• See also Cancel export.

Dataflow window

1. On the Dataflow window, right-click on an acoustic variable, select Export and choose from
• To Matlab Format...
• Complex To Matlab Format...
2. In the export dialog box, specify the Export options.
3. Click Export...

Dataflow Toolbox

1. Drag the Measurements - MATLAB object from the Dataflow Toolbox to the Dataflow window. This is listed under the Exporters category.
2. Right-click or double-click the Measurements - MATLAB object. In the Exporter Properties dialog box, set the Operand to the desired variable.
3. Adjust export settings in the Measurements - MATLAB page.
4. Double-click the exporter object in the Dataflow window to enter a file name and export the data.
5. Click Save.

Echogram

1. Display an Sv, TS or angular position echogram.
2. On the Echogram menu, point to Export and choose from
• Sv Values to Matlab...
• TS Values to Matlab...
• Complex Sv Values to Matlab...
• Complex TS Values to Matlab...
• Angular Positions to Matlab...
3. In the export dialog box, specify the Export options.
4. Click Export...

Selection/region on an echogram

Export from a selection or region on an echogram is supported for single beam data. This is not available for complex data.

1. Display an echogram.
2. Make a selection or select a region.
3. On the Shortcut menu (right-click), select Export Selection or Export region and choose from
• Sv Values to Matlab...
• TS Values to Matlab...
• Angular Positions to Matlab...
4. In the export dialog box, specify the Export options.
5. Click Export...

Table

1. Display a Table.
2. On the Table menu choose from
• Export to Matlab...
• Export Complex to Matlab...
3. In the export dialog box, specify the Export options.
4. Click Export...

MATLAB file format

Echoview provides data similar to the equivalent data export in *.csv format.

Echoview exports the data for a ping as a row in MATLAB format. Prior to Echoview 7, each ping data was a column.

MATLAB scripts that are written for ping data in columns will require the data in Echoview 7 MATLAB export files to be transposed. The following Octave code snippet to transposes Echoview export data:

octave:164> Var=[]; for x=1:length(PingNames), Var=[Var,eval(PingNames{x})]; clear(PingNames{x}); end
        octave:165> Data_values=transpose([Var.Data_values])
    

Note: Under MATLAB/Octave PingNames(x) must be written PingNames{x} since PingNames is cells.

Complex data

Echoview handles complex data as {r, r, r... i, i, i...} and then uses Matlab table writing code to create a single Matlab complex array structure.

See also

About exporting data
About Exporter objects
Export file formats
About exporting measurement data