How to make auto generate variable name and save to .jpg format?

i have code like this :

    global datasetNumber;
    img = getframe(gca);
    baseFileName = sprintf('%d.jpg', datasetNumber);
    filename = fullfile(fullfile('H:\SKRIPSI\Citra Latih 2\', baseFileName));
    imwrite(rgb2gray(img.cdata),filename,'jpg');
    datasetNumber = datasetNumber +1; % Increment for next time.

I want to save an image from an axes, when I save by using the code above, each of the image does not have a file name. I want to save the image that have a file name like 1.jpg, 2.jpg, 3.jpg, and so on without any restrictions in the store a lot of images. how can I make that?

[Adam]

What do you mean by "doesn't have a filename"? At a glance that looks like it should work, although why datasetNumber is global is questionable and it depends how you are looping round this since you didn't include that code. I assume datasetNumber just parachutes in from somewhere initially, but if you are using a global in the middle of a for loop then it may well just use the same number each time. I never use globals because they are very bad programming style so I don't remember how they would behave like that.

[Alvindra Pratama]

I mean, every time I save drawings that I save do not have a name, as shown below:

so what should I do with the global?

Answer 1

[the cyclist]

Here is a simple example for variable-based file names:

nRange = 1:3;

for n = nRange
    plot(rand(7))
    filename = ['test ',num2str(n),'.jpg'];
    print('-djpeg',filename)
end

[Alvindra Pratama]

if i use nRange = 1:3, it means that I could only save three pictures only. Here I want to save the image as much as possible without limitation, how can I do?

[mahrukh jamil]

Hello, I have some how similar question. What if i want to extract the part of my data and save it as .mat file incremented number. for example

ECG_data_sub1=ECG(data);
  do something
  ECG_data_1;
  ECG_data_2;
  ....
  ECG_data_n;

    now can anyone tell me how can i generate and save this incremented file name ECG_sub1_1, ECG_sub1_2... ECG_sub1_n.
    Thank you

[Image Analyst]

Bad idea mahrukh. See the FAQ http://matlab.wikia.com/wiki/FAQ#How_can_I_create_variables_A1.2C_A2.2C....2CA10_in_a_loop.3F Incrementing filenames (string contents) is okay, like the cyclist showed, but not variable names. You can extract the parts of the array into a new array or a single variable, and then save that to one or more mat files, and that's okay, but don't make new variable names that have the index built into the name itself.

[mahrukh jamil]

Thank you for your answer. well i can only name it with numbers. What syntax should i use if I want to develop a function for the extraction of files and then name those file according to numbers. for example. i have 10 subjects. i want to run a function foe each subject and the resulting file should have a name with the number of subject.

function ECG_extraxt(ECG_data, subject_number)
N_max=length(ECG_data);
fs=256;
time = (0:N_max-1)/fs;

EKG_subject_number=[time; ECG_data];

% save('EKG_subject_number.mat', 'EKG_subject_number')

 end
how can i have this subject number with my final file name. Or the same condition apply for it too as it were for variables with numbers in a loop?

[Kodali]

Try this when subject and number have values filename=strcat('EKG_',num2str(subject),'_',num2str(number),'.mat'); save(filename)