java heap error when opening txt file

Hello,

when opening a txt-file with

fid = open('testfile.txt');

I am getting an error:

Exception in thread "AWT-EventQueue-0": java.lang.OutOfMemoryError: Java heap space
	at javax.swing.text.GapContent.allocateArray(GapContent.java:94)
	at javax.swing.text.GapVector.resize(GapVector.java:214)
	at javax.swing.text.GapVector.shiftEnd(GapVector.java:229)
	at javax.swing.text.GapContent.shiftEnd(GapContent.java:345)
	at javax.swing.text.GapVector.open(GapVector.java:201)
	at javax.swing.text.GapVector.replace(GapVector.java:142)
	at javax.swing.text.GapContent.insertString(GapContent.java:132)
	at javax.swing.text.AbstractDocument.handleInsertString(AbstractDocument.java:723)
	at javax.swing.text.AbstractDocument.insertString(AbstractDocument.java:707)
	at javax.swing.text.PlainDocument.insertString(PlainDocument.java:130)
	at javax.swing.text.DefaultEditorKit.read(DefaultEditorKit.java:273)
	at com.mathworks.widgets.datamodel.TextFileBackingStore.readIntoDocument(TextFileBackingStore.java:200)
	at com.mathworks.widgets.datamodel.TextFileBackingStore.loadDocumentFromFile(TextFileBackingStore.java:169)
	at com.mathworks.widgets.datamodel.TextFileBackingStore.doLoad(TextFileBackingStore.java:241)
	at com.mathworks.widgets.datamodel.TextFileBackingStore.doLoad(TextFileBackingStore.java:32)
	at com.mathworks.widgets.datamodel.AbstractBackingStore.load(AbstractBackingStore.java:114)
	at com.mathworks.mde.editor.EditorView.reload(EditorView.java:410)
	at com.mathworks.mde.editor.EditorView.initSyntaxTextPane(EditorView.java:862)
	at com.mathworks.mde.editor.EditorView.<init>(EditorView.java:222)
	at com.mathworks.mde.editor.EditorView.<init>(EditorView.java:153)
	at com.mathworks.mde.editor.EditorViewClient.init(EditorViewClient.java:232)
	at com.mathworks.mde.editor.EditorViewClient.<init>(EditorViewClient.java:181)
	at com.mathworks.mde.editor.MatlabEditorApplication.createEditorViewClient(MatlabEditorApplication.java:700)
	at com.mathworks.mde.editor.MatlabEditorApplication.createEditorViewClient(MatlabEditorApplication.java:685)
	at com.mathworks.mde.editor.MatlabEditorApplication.createEditorViewClientFromExistingFile(MatlabEditorApplication.java:677)
	at com.mathworks.mde.editor.MatlabEditorApplication.access$300(MatlabEditorApplication.java:73)
	at com.mathworks.mde.editor.MatlabEditorApplication$4.runWithOutput(MatlabEditorApplication.java:402)
	at com.mathworks.jmi.AWTUtilities$Invoker$2.watchedRun(AWTUtilities.java:475)
	at com.mathworks.jmi.AWTUtilities$WatchedRunnable.run(AWTUtilities.java:436)
	at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311)
	at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758)
	at java.awt.EventQueue.access$500(EventQueue.java:97)
    

The file is approximately 820MB large. My system has 16 GB of ram. I changed java heap space under preferences to up to 4 GB, but that does not change anything (it just takes longer for the error to appear -> matlab is busy for a longer time)

I think 820MB shouldn't be too large, so what could I do differently? Btw, I tried this in 2018b and 2019b.

Kind regards.

Answer 1

[Jan]

"I think 820MB shouldn't be too large"

What is the purpose to open a 820MB file in Matlab's editor? What do you want to do with it there?

Matlab's editor is not designed for such large files. Try Notepad++, if you are working on Windows. Under Linix I'd open it with vi.

[Nick]

I want to open it to read data from it with

readline = fgets(fid);

[Nick]

Okay, I got essentially the same with importdata(). Thank you.

[Jan]

Then you need fopen(FileName, 'r'), not open.

[Nick]

Thank you!