Comments and Ratings

Hi Micah,
   i´m using IP - camera Airlive Ovislink, which sends out only JPEG stream and can be played with web browser or some IP View software. I am wondering if it is possible to use your kit to generate stream video in Matlab and possibly to use it in real time in some advanced Blockset such Video and Image Processing. I was only succesful to get slow image stream to Matlab with use of imread('http://192.168.1.25/image.jpg') and its cycle in time. But this is really quite slow solution and not sufficient.
I really couldn´t find solution anywhere, so i appreciate any advice. Thanks in advance!

Bob:
set(gcf, 'color', 'none'); % Set the figure background to transparent
set(gca, 'color', 'none'); % Set the axes background to transparent

With regard to the program failure when a legend handle is found, I changed the "&&" to "&" on line 60 and changed the "Legend" to "legend" on line 61 and the program properly neglects the legend handle.

Thank u Johan, I downloaded "centeraxes", it solved my problem.
How do I get the axes ticked from -1 to 1 please? now it's ticked only from -0.9 to 0.9.
Thanks again
Mario

Thanks Nathan for comments. I guess most people prefer gray background. In the latest version the colors (bg/fg) are easy to customize.

tnx

We are working on a project called I-JAUS (please look for videos about it). We would like to add to our installation package your work, because it is perfect for showing how to control a robotic arm with the eyes.
Could you authorize us? Of course we'll keep your licence headers, and mention all of you in our acknowledgement sections (thesis report, and I-JAUS package).

Regards,

Mauricio Jost
Estudiante de Ing. en Computación
FCEFyN - UNC - Argentina

Hi Sahinder,

HAve a look in matlab help files. There you can find all the information about importing xls data into matlab.

Cheers.
Marcelo.

Overall a nice package. However, I found several issues with the DCM to quaternion block. The block is not designed to accept a [3x3] signal dimension, rather, it expects a 9 element vector. Also, if one uses a reshape on a [3x3] vector to recast is as the 9 element vector one needs to transpose the [3x3] first since the 9 element vector is unpacked in row order, rather than the Simulink standard of column order.

Also, the quaternion to DCM block outputs the DCM in row-order, which requires a reshape and transpose to recast as a usable [3x3] signal.

Also several of the blocks use Mux blocks as bus creators improperly which will generate errors if strict bus modeling is enabled.

Great job;
It realy helped me,
Thanks.

Now I see... it does not use transaction costs: we sholud use:

pnl = ([0;x(2:end).*sig2(1:end-1)]);

instead of:

pnl = ([0;x(2:end).*sig2(1:end-1)-abs(diff(sig2))*0.000028]);

Wasn't it?

Thanks a lot

Thank you, Ivo. Your suggestion helped me - I also use xlsread1 from another function.

Gernot,

1) The "no models (not yet working)" message in the AC model selection pane is because that function has not yet been completed. You can however type in the model names in the "AC _Name" text box.
2) You must download JSBSim seperately as in my instructions and place the JSBSim folder in exactly the location specified, otherwise, you will not have any aircraft files to load (AC model files are in the JSBSim download.)

Please first confirm that you have downloaded JSBSim and placed its folder in the JSBSimSFunction_GUI folder (the one that is populated with files) and then test and let me know the results. I compiled this version slightly differently (to run a bit faster,) so I am hoping that it is not the cause of the "Invalid MEX-file." Other users have successfully run my previously compiled versions with R2009a.

Regards,
Brian

And I have a problem about to creating mat-file . I must to use my excell data .How can I solve this problem. I think that "Creating Mat file in C "; but I can not solve my problem because I don't have enough source . Could you help me?? Thanks for your all attention.

Şahinder Kaya
İstanbul Technical University

Mathematical Engineer

kayasah@itu.edu.tr

Just an aesthetic note: The color is Terrible. Choose something less intrusive...

This model was only tested with the MATLAB release listed above (7.0.1) and a few others. A version of this model which works with the current release of MATLAB and Simulink is shipped with the Communications Blockset called commbluetoothvoice.mdl

Enter at the command line:
>>commbluetoothvoice

Problem:
Hi, thanks for the great program. It works for about 2000frames read in a loop in my videos (which contain about 9000 uncompressed avi frames). But then i can see that matlab eats more and more memory until it interrupts. BUT: this is only the case in this program:
try
            output_picture = frame2im(aviread(filename_in,framenumber));
catch
    [avi_hdl, avi_inf] = dxVideoOpen(filename_in);
    pixmap = dxVideoReadMex(avi_hdl, framenumber);
    img = reshape(pixmap,[avi_inf.Height,avi_inf.Width,3]);
    dxVideoCloseMex(avi_hdl);

    output_picture = img;
end
If i remove the try, catch , end and the aviread command, there's no problem.

Is there any possibility to first try to read the frame with aviread (as it is very fast) and only use dxVideo if aviread fails?

Thanks a lot! I really would like to use your script as it is much faster than mmread.

Andreas,

Thanks for the bug report (and I'm a little embarrassed by such blatant bugs in my very demo...).

I fixed the bugs, added a couple more features, and uploaded the updated files.

I could not test it. Should it run on Matlab2009a?
1) no models are selectable in the gui: .. (not yet working)
2) initialize model parameters: ERROR:
??? Error using ==> JSBSimGUI>init_model_Callback at 1774
Error due to multiple causes:
--> Invalid MEX-file
'C:\E_Data\Lehre\FUP\F0902_AirbugSimpleControl\subJSBSimSimulink\JSBSim_SFunction_GUI\JSBSim_SFunction.mexw32':
Diese Anwendung konnte nicht gestartet werden, weil die Anwenungskonfiguration nicht
korrekt ist. Zur Problembehebung sollten Sie die Anwendung neu installieren.

I know nothing about Fortran, and had to convert some code into Matlab. The conversions that f2matlab made helped me immensely to give me a starting point. Many thanks!

The pre-allocation and the use of logicals is certainly an improvement. Next try to improve the help section. See any standard function for inspiration how to set up such a comment section, for instance, DISP or MEAN. Also take a look at LOOKFOR to learn about H1 lines.

Thank you very much for posting this.It is really very helpful to implement bch decoder in hardware.I am new to matlab.So please tell me how to change the syndrome values?

Thanks in advance

Returning on the issue for compressing large matrices, I made the following patch. It chunks byteData into blocks of 5MiB, and write the output to a structure, which has some information about chunksize and the size of the uncompressed byte array.

The amount of heap space available for compression is rather unpredictable. Sometimes 10MiB blocks were too large. The command 'java.lang.Runtime.getRuntime.freeMemory' does not return a usable value either.

The use of a structure produces an extra overhead of 736 bytes compared to your current version. This can be significantly reduced to 24 bytes if the blocksize/uncompressed size information is stored in the byte array as well. However, I found this method more clear, and the overhead is minimal for larger data, which cannot be compressed currently.

The CompressLib.test shows that all compressions were succesful.

The only thing which cannot be compressed now are sparse matrices. (I have got something working, but I have no idea how to get it compiled on windows, so I do not want to submit it on the FX now.)

Many thanks for your work! It helped me solving a lot of memory issues.

Sebastiaan

Patch:
diff old/CompressionLib/CompressLib.m new/CompressionLib/CompressLib.m
43c43
< function out = decompress(byteArray)
---
> function out = decompress(compressedData)
46c46
< % out = CompressLib.decompress(byteArray)
---
> % out = CompressLib.decompress(compressedData)
48,49c48,49
< % Function will decompress "byteArray" (created by CompressLib.compress).
< % "byteArray" must be a 1-D array of bytes (uint8).
---
> % Function will decompress "compressedData" (created by CompressLib.compress).
> % "compressedData" must be a compression structure.
59,71c59,77
< if ~strcmpi(class(byteArray),'uint8') || ndims(byteArray) > 2 || min(size(byteArray) ~= 1)
< error('Input must be a 1-D array of uint8');
< end
<
< %------Decompress byte-array "byteArray" to "byteData" using java methods------
< a=java.io.ByteArrayInputStream(byteArray);
< b=java.util.zip.GZIPInputStream(a);
< isc = InterruptibleStreamCopier.getInterruptibleStreamCopier;
< c = java.io.ByteArrayOutputStream;
< isc.copyStream(b,c);
< byteData = typecast(c.toByteArray,'uint8');
< %----------------------------------------------------------------------
<
---
> if isstruct(compressedData) && ~isfield(compressedData, 'compressed') && ~isequal(compressedData.compressed, 'GZIP')
> error('Input must be a compression structure.');
> end
>
> % Reserve memory
> byteData = zeros(compressedData.UncompressedSize, 1, 'uint8');
>
> % Decompress data in chunks
> for Iter=1:length(compressedData.Data)
> %------Decompress byte-array "byteArray" to "byteData" using java methods------
> a=java.io.ByteArrayInputStream(compressedData.Data{Iter});
> b=java.util.zip.GZIPInputStream(a);
> isc = InterruptibleStreamCopier.getInterruptibleStreamCopier;
> c = java.io.ByteArrayOutputStream;
> isc.copyStream(b,c);
> byteData((Iter-1)*compressedData.BlockSize+1:min(Iter*compressedData.BlockSize, length(byteData))) = typecast(c.toByteArray,'uint8');
> %----------------------------------------------------------------------
> end
>
74d79
< end
76c81,83
< function byteArray = compress(in)
---
> end
>
> function compressedData = compress(in)
79c86
< % byteArray = CompressLib.compress(in)
---
> % compressedData = CompressLib.compress(in)
88c95
< % Outputs an array of type uint8. Use CompressLib.decomress to decompress
---
> % Outputs a compression structure. Use CompressLib.decomress to decompress
98,106c105,120
< %-------compress the array of bytes using java GZIP--------------------
< f=java.io.ByteArrayOutputStream();
< g=java.util.zip.GZIPOutputStream(f);
< g.write(byteData);
< g.close;
< byteArray=typecast(f.toByteArray,'uint8');
< f.close;
< %----------------------------------------------------------------------
< end
---
> % Compress data in chunks
> compressedData.compressed = 'GZIP';
> compressedData.BlockSize = 5*1024^2; % Make 5 MiB chunks
> compressedData.UncompressedSize = length(byteData);
> compressedData.Data = cell(ceil(compressedData.UncompressedSize/compressedData.BlockSize), 1);
> for Iter = 1:length(compressedData.Data)
> %-------compress the array of bytes using java GZIP--------------------
> f=java.io.ByteArrayOutputStream();
> g=java.util.zip.GZIPOutputStream(f);
> g.write(byteData((Iter-1)*compressedData.BlockSize+1:min(Iter*compressedData.BlockSize, compressedData.UncompressedSize)));
> g.close;
> compressedData.Data{Iter}=typecast(f.toByteArray,'uint8');
> f.close;
> %----------------------------------------------------------------------
> end
> end