How to save matlab coding output data in a file?
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Hello,
I am working with matlab coding. I need to run the simulations for different models. For the 1st model, I run the simulation, it saves output in the workspace. but when i run the 2nd model, it saves the output file for the 2nd model. That is why i need to save the output for the 1st model to a file. So, i can store my outputs of all models.
can anyone please suggest me how to do?
11 个评论
Walter Roberson
2019-2-8
is this a Simulink question ?
madhan ravi
2019-2-8
Sky Scrapper
2019-2-8
编辑：Sky Scrapper
2019-2-8
Sky Scrapper
2019-2-8
madhan ravi
2019-2-8
Why not use save() ?
Sky Scrapper
2019-2-8
madhan ravi
2019-2-8
It saves in a file named finaloutput.mat to use the values simply use
load finaloutput.mat % variables will be loaded in workspace
Sky Scrapper
2019-2-8
Walter Roberson
2019-2-8
Do not save naming .m file as destination . Name a .mat file.
采纳的回答
Omer Yasin Birey
2019-2-8
编辑：Omer Yasin Birey
2019-2-8
0 个投票
14 个评论
Sky Scrapper
2019-2-8
Omer Yasin Birey
2019-2-8
编辑：Omer Yasin Birey
2019-2-8
Hi, you should have written 'finaloutput.mat' not 'finaloutput.m'. Try this
m = matfile('finaloutput.mat','Writable',true);% now you will use m to save
m.oldVariable = variableThatYouWantToSave; %its the variable that you want to save
and after your new simulation you can add the new variable into this matfile
m.newVariable = newVariableThatYouWantToSave;%new variable
Sky Scrapper
2019-2-8
编辑：Sky Scrapper
2019-2-8
Omer Yasin Birey
2019-2-8
编辑：Omer Yasin Birey
2019-2-8
save('finaloutput.mat','p','q','-append')
Don't forget to write '-append' at the end otherwise it will write the variables over your existing variables. Meaning that your old variables will be deleted.
Sky Scrapper
2019-2-8
编辑：Sky Scrapper
2019-2-8
Omer Yasin Birey
2019-2-8
load('finaloutput.mat')
This line above will bring you the old variable.
About the directory, the mat file will be in the folder that you work in. When you write the line above, the variables will appear in the workspace.
Sky Scrapper
2019-2-8
Omer Yasin Birey
2019-2-8
编辑：Omer Yasin Birey
2019-2-8
That has to be something else, q is a valid variable name. Maybe, you are missing an apostrophe between the commas or something.
Sky Scrapper
2019-2-8
Omer Yasin Birey
2019-2-8
To use matfile object, m, you have to write this line for each variable
m.oldVariable = variableThatYouWantToSave;
m.newVariable = new;% etc
But it is strange that 'q' is giving that kind of error.
Sky Scrapper
2019-2-8
Omer Yasin Birey
2019-2-8
Unfortunately, matfiles doesn't have remove option. But at this link the user wrote a function for this. You can use it by copying the .m file into your folder. It seems working
Sky Scrapper
2019-2-8
Stephen23
2019-2-8
"Don't forget to write '-append' at the end otherwise it will write the variables over your existing variables. Meaning that your old variables will be deleted."
Yet that is exactly what the -append option does for .mat files: it overwrites existing variables of the same name, which confuses a lot of beginners (it would be better named overwrite or something similar). This is explained in the save help (and easily checked with a few tests).
The suggested answer to use matfile is pointlessly complex for this trivial task. Much simpler to use save in a loop, generating the filename each time:
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