8. OUTPUT FILES
SAVE YOUR OUTPUT!
When Michlet is run, one of the first things it does is to clear
its output files by placing the character string # Blank in each
file. If you have not copied the files to a safe directory before running
Michlet, previous output will be over-written. I have found it very useful
to create some small batch files (or scripts in Unix) that copy data to
safe directories or to floppy or compact disk.
out.mlt
This comma-separated text file is created when you exit from Michlet.
The file contains, among other output quantities, details of the
hullforms, tables of resistance, and an array of (dimensionalised)
hull offsets. If drag was not calculated before exiting Michlet, all
resistances in this file will be equal to zero.
Certain quantities are not calculated in this version. If the
words 'Not calculated' or 'Not' appear next to a label in the
output file, it means that the calculation of that quantity is
crippled in the current version.
More Output Files
Some users like the fact that nearly all output data is contained in
the one file, namely out.mlt; others prefer to make up their
own data sets using small files that contain specific information,
such as particular components of resistance. The following files
contain information that is in out.mlt but in a format more suitable
for processing by Unix utilities, DOS batch files etc. All files listed
below will be cleared when Michlet is run. You should save any output
immediately after Michlet terminates.
- HULL OFFSET ARRAYS
- off1.mlt, ..., off5.mlt : dimensional hull offsets for hull 1, ...,
hull 5.
- fsoff1.txt, ..., fsoff5.txt : dimensional hull offsets for hull 1, ...,
hull 5 in a format that can be read by FREE!Ship. Note that the offsets
are saved section by section from the aftmost to the bowmost. This is
opposite to Michlet's convention in which the first station is the bowmost.
- hsecarea.mlt : section areas
- hwparea.mlt : waterplane areas
- MODEL AND VESSEL PARTICULARS
- course.mlt : course details
- model.mlt : model particulars
- physics.mlt : physical parameters
- hull.mlt : hull details
- ship.mlt : ship particulars
- SPEED DEPENDENT VECTORS AND ARRAYS
- u.mlt : ship speeds
- Hull vectors and arrays
- hat.mlt : transom area
- hbml.mlt : Longitudinal BM
- hbmt.mlt : Transverse BM
- hbt.mlt : transom beam
- hd.mlt : displacement
- hfside.mlt : side force (Crippled)
- hheel.mlt : heel angles
- hiwpl.mlt : longitudinal waterplane moment of inertia
- hiwpt.mlt : transverse waterplane moment of inertia
- hlcb.mlt : longitudinal centre of buoyancy
- hlcf.mlt : longitudinal centre of flotation
- hrf.mlt : frictional resistance
- hrform.mlt : form resistance
- hrh.mlt : hydrostatic resistance
- hrlee.mlt : resistance due to leeway (Crippled)
- hrr.mlt : residuary resistance
- hrt.mlt : total resistance
- hrw.mlt : wave resistance
- hrwd.mlt : diverging wave resistance
- hrwt.mlt : transverse wave resistance
- hs.mlt : wetted surface area
- hsecarea.mlt : section areas
- hsink.mlt : sinkage
- htrim.mlt : trim angles
- htt.mlt : transom draft
- hvcb.mlt : vertical centre of buoyancy
- hvff.mlt : viscous drag form factor
- hwff.mlt : wave drag form factor
- hwparea.mlt : waterplane areas
- hxcp.mlt : x-ordinate of centre of pressure (Crippled)
- hzcp.mlt : z-ordinate of centre of pressure (Crippled)
- Ship Vectors
- sfside.mlt : side force (Crippled)
- srf.mlt : skin friction resistance
- srform.mlt : form resistance
- srh.mlt : hydrostatic resistance
- srlee.mlt : resistance due to leeway (Crippled)
- srt.mlt : total resistance
- srv.mlt : viscous resistance
- srw.mlt : wave resistance
- srwd.mlt : diverging wave resistance
- srwdint.mlt : diverging wave interference resistance
- srwint.mlt : wave interference resistance
- srwt.mlt : transverse wave resistance
- srwtint.mlt : transverse wave interference resistance
- ship_output_by_speed.mlt : This file contains most of the data
listed above in comma-separated columns.
- THETA DEPENDENT VECTORS AND ARRAYS
- drdth.mlt : theta (degrees) and dR/dtheta (kN).
Wave Elevation and Resistance Output Files
Resistance graphs, wave elevation contour plots and free wave spectrum graphs
can be saved as .pcx files. Wave elevations and free wave spectra can also be
saved as text (.mlt) files. Press s to save the data for wave elevations.
A prompt will appear asking for a filename (maximum 8 letters). The extension .mlt
will be appended automatically. Press S to save a resistance,
wave elevation or free wave spectrum plot as a .pcx file. The .pcx extension will
be added automatically.
It is very important to note that wave elevation data is not saved
automatically on exit. After you display wave patterns or wave cuts
you should save the data, or the graphic, or both.
The table below is an example output file of wave elevations for a
small rectangular patch using a 5x5 grid. Of course, for real
work, the size of the output file will be much larger. Also,
the elevations will not always be symmetric around y=0.0 for all
ships and all rectangular patches. Output is comma-separated, and
can be pasted into Excel spreadsheets.
RECTANGULAR PATCH
Speed
6.0000
x0,x1,nX
20.0000,40.0000,5
y0,y1,nY
-10.0000,10.0000,5
x_zmin,y_zmin,zmin
40.0000,-5.0000,-0.0227
x_zmax,y_zmax,zmax
20.0000,-5.0000,0.0139
ELEVATIONS
z,20.0000,25.0000,30.0000,35.0000,40.0000,
10.0000,0.0011,-0.0002,-0.0012,0.0033,-0.0032
5.0000,0.0139,-0.0166,-0.0002,0.0095,-0.0227
0.0000,0.0028,-0.0033,0.0015,0.0001,0.0011
-5.0000,0.0139,-0.0166,-0.0002,0.0095,-0.0227
-10.0000,0.0011,-0.0001,-0.0012, 0.0033,-0.0032
Speed is in metres/sec. x0,x1,y0, and
y1 are the ordinates (in metres) of the corners of the patch.
nX and nY are the number of grid nodes in the X- and
Y-directions.
x_zmin and y_zmin are the co-ordinates (in metres) of
the minimum wave elevation in the rectangular patch. zmin is
the minimum wave elevation. x_zmax and y_zmax are the
co-ordinates (in metres) of the maximum wave elevation in the
rectangular patch. zmax is the maximum wave elevation.
Wave elevations, z, are given as a table of values. The first
row contains the x-ordinates of the grid points of the rectangular
patch; the first column contains the y-ordinates for the patch.
This file can be used as an input file for the ship-identification
objective in GODZILLA by renaming it as userrecp.mlt. No other
changes to the file are necessary, making it easy to use with DOS
batch files or Unix scripts.
Output files for the sectorial patch and the wave cuts have a very
similar format to the above table.
Output Formats
The variety, type, and format of output files is controlled by the values
of the two input variables Output File Type and
Output File Subtype in the in.mlt input file. For example, in
addition to the files described above, Michlet can output files that make
it easy to create lines drawings using public domain programs like gnuplot,
or to automatically generate text and tables using LaTeX. Description of
the many different possibilities is beyond the scope of this manual.
Back to Index.