Try running resource: "Main Component Analysis"


I was trying to run the “Main Component Analysis” feature.

But I received the message as per the image of the file: “processing_img02.png”, attached.

The error message is that it is in the image of the file:“processing_img03.png”

Does anybody know how to solve this?

Are you running other software that uses significant memory space (e.g., web browser)? You should mention the platform, amount of RAM, details of your data (image size) and the setting (Xmx value) for Java heap space from SNAP’s Tools/Options/Performance setting page. All the supported OS’s have tools to monitor memory usage. If the Xmx value is too small you may see a large value for unused memory. or you may see that most of the memory is being used by some other program.

For most people the solution is either reducing the size of the images or installing more RAM, but sometimes (e.g., RAM added after SNAP was installed or other processes using a lot of RAM) you can get your job to run without drastic measures.


At the time I was processing I just left the SNAP running. I thought it might be a memory issue.

But I believe that my machine I’m using has a reasonable configuration to run SNAP.

The image I’m using is about 900Mb.

And follow in the images the configuration of my machine and the option of performance configured in the SNAP.

I should mention that “Main Component Analysis” is also called “Principle Component Analysis” (PCA) in case others are searchiing for PCA and Java heap space.

Is that 900M bytes per band or the whole file?

I agree that your machine should be suitable for SNAP (assuming it is not doing other heavy work at the same time). PCA memory use depends on the actual data. Some images are highly compressible, so size on disk may be a fraction of the size of the arrays in PCA.

I just ran PCA on 5 bands (10 million pixel float32 bands,~200MB) ocean color data. The PCA took only a few seconds on a low-end laptop with 16GB RAM. SNAP’s memory usage increased to 4.5GB.

I suggest you try processing a reduced ROI while using Task Manager to watch SNAP’s memory usage. The “Performance” display will summarize overall memory usage. You can also see if other programs are using a lot of RAM. If you start with 1/4 of the full ROI, then try 1/2 size you will get a feel for what size ROI your system can handle.