I am trying to save real-time streaming data obtained from hardware to Matlab workspace, I use the following command: My issue is, it only saved the last set of data, but not all data.
To save all variables from the workspace in binary MAT-file, test.mat, type
save test.mat
When I tried with this
save('test.mat','-append'); ,
it makes my program halt, so I would like to know what is the correct way to achieve this?
They have same name and they are constantly overwritten, I did not get error message, I still get the file saved but I noticed that it only showed the latest set of data, what should I do to avoid this? I want it to save every set at each time step
The correct syntax for appending using save is
save(filename,variables,'-append')
This will save append all new variables and overwrite variables already in the filename.mat with the updated values.
Related
I am working on a project where I have to save data of scope. I am using the code shown below but its not working for me as I want to save the data after every iteration. How can I do that?
for i =1:numel(All_IR)
IR=All_IR(i)
simOut=sim('ModelName')
Loggings(i).scopeData=scopeData
end
I am working on an experiment that take a lot of data samples and save it to different video files. For example, I take data and save it to a file called "slowmotion.avi" and then I take another set of data and save it to another file called "normalspeed.avi".
I am trying to find a way that I could change the name of file being saved without editing the code. The way I am using right now makes me have to open the code and change the name of the file directory within the code and then save the code. I want to make it a lot faster and easier to use.
I have tried the following code to fix this problem but it doesn't work.
graph=input('Graph of experiment: ');
vidObj = VideoWriter('%3.1f.avi\n',graph);
.....
Hope I didn't confuse you.
A possible solution:
graph=input('Graph of experiment: ','s');
vidObj = VideoWriter([graph,'.avi']);
The 's' in the input() function indicates that the expected input is a string, and [graph,'.avi'] simply concatenates both strings.
I have got this really strange error in matlab. When I try to run the command
save(fullfile('filepath','filename'),'var','-v7');
I get the error message,
error using save can't write file
but when I try
save(fullfile('filepath','filename'),'var','-v7.3');
everything works fine. The the variable takes some space on the workspace, 165MB, but the I would guess that the size should not be an issue here. Does anyone know why it does not work to save in v7?
For the one that want to confirm the size of the variable, I will add the whos information,
Name Size Bytes Class Attributes
myName 1x1 173081921 struct
BR/ Patrik
EDIT
The variable I try to save is a struct with plenty of fields. I have tried to save a 3 dimensional matrix of size 800 mb, which went through without problems.
This is not an exact match to your problem, but I received the same error message when trying to save to -v6 format. Matlab is supposed to issue an error when a variable type or size is not supported:
help save
...
If any data items require features that the specified version does not support, MATLAB does not save those items and issues a warning. You cannot specify a version later than your version of MATLAB software.
Matlab's error checking seems to not be perfect, because there are certain situations (dependent on Matlab version and the particular variable type) that just fail all together with this not so helpful error message:
Error using save
Can't write file filename.mat.
For example, saving a string with certain unicode characters with the '-v6' option in Matlab r2015b in Linux produces the error, but Matlab r2016a in Windows does not. This is the output from my Matlab r2015b session:
>> A=char(double(65533))
A =
?
>> save('filename.mat','-v6','A')
Error using save
Can't write file filename.mat.
Without having your specific variable to test with, but seeing that the error messages match, I suggest removing parts of your data structure until it will save in order to isolate the variable that is causing it to fail.
I am going through someone's data analysis files (created in an older version of matlab) and trying to find out what a particular .mat file is that was used in a matlab script.
I am trying to load a .mat file in matlab. I want to see what is in it.
When I type...
load ('file.mat')
the file loads and I see two variables appear in the workspace. jobhelp and jobs.
When I try to open jobs by typing the following in the matlab command window...
jobs
the response is..
jobs =
[1x1 struct]
Does this mean that there is only a 1 x 1 structure in the .mat file? If so, how in the world do I see what it is? I'm even happy to load it in unix, but I don't know how to do that either. Any help would be greatly appreciated as I have a few files like this that I can't get any information from.
Again, a new user, so please make it simple.
Thanks
It means that jobs is a cell array {} and within this cell array is a structure defined
To see the structure and its contents type jobs{1}
I think you are dealing with a SPM5 Batch-File. This variable is an image of the tree-like structure you can see in the Batch-Editor of SPM. Your job consists of one subitem (stats) which could have various subsubitems (like fMRI model specification, model estimation and so on).
To access this structure on the command line just proceed like Nick said:
Each level is a separate cell array that you can access with {#} after the name of the level. Example: jobs{1} shows you that there is a subitem named stats.
Subitems in structs are accessed with a dot. Example: jobes{1}.stats{1} shows you the subitems of the stats-entry.
Notice that there could be more than one entry on each layer: A stats module could (and probably would) contain various subitems. You can access them via jobs{1}.stat{2}, jobs{1}.stats{3} and so on.
The last layer would be the interesting one for you: The structures in here is an image of the options you can choose in the batch-editor.
hye everyone i m doing my project "automatic vechicle identification".i have to design software in matlab,i have done extraction of plate region ,segmentation of characters,...now i want to save these segmented characters so that i can further recognize these character from a data base......any body can help me please feel free to write to me, thanks in advance
So if you have some data, myData then you can just issue a command save myData and you will have a new file in the current directory named myData.mat. To load the data later, just type in load myData and then you will have a new variable in the workspace named myData. There's lots more you can do with this, so you should check out help save.
Alternatively you could use a database. I've never actually used a database in Matlab, but there seems to be plenty of information about how one would go about doing this: http://www.mathworks.com/help/toolbox/database/ug/database.html