Why can the binary file not be opened?

Hello!

I am trying to open data from a binary file, but fopen gives -1 (which apparently means that some error occurred). So, what could this mean?

You can actually find a description of my data and the file online, which might be more helpful than my poor description of the data, as I am new to programming. Here is the link to download the data: http://glcf.umd.edu/data/ndvi/ and below, you find the description. Thanks for all advice!

So here is the description of the three files which I'd like to load:

• Projection: Sinusoidal - reprojected from Integerized Sinusoidal - Central Meridian used was 55d00'0.0" W (central latitude of 0d)
• There are three data files: 1 contains the NDVI, the other two contain the MODIS bands 1 and 2 respectively
• Image Size: 14819 Pixels x 8896 Lines
• Upper Left Corner: 73.31578801563607d W 0.001124150740324725d N (UL -2036621.843 E 125.00 N meters)
• Lower Right Corner: 39.03545054942156 W 19.99976582111718d S (LR 1668122.392 E -2223871.446 N meters)
• Corner points in meters are relative to the point 55d' W 0d. If your software has a different default central latitude you may need to apply a false northing.
• As a result of the native I-sin grid there may be shift of up to 1 pixelin the latitude range 0 - 8 degrees South. This issue is currently beingaddressed and the data will be replaced when it is resolved.
• There are three data files: - 1 NDVI file: SA...NDVI.bin - 2 Band files: SA...Band"n".bin (where "n" is either 1 or 2)
• Data format for the NDVI file is binary with 8 bit Unsigned integer
• Data format for the Band files is binary with 16 bit Unsigned integer
• A bitmap was applied to mask out the shallow water along the coastlinesand in Lake Titicaca
• NDVI scaling: - To obtain the actual NDVI value from the Dn (digital number) use the following formula: (Dn - 128) / 100 = NDVI
• A full description of the compositing procedure will be available as a link from the product description page on the website. http://glcf.umiacs.umd.edu/MODIS/product.htm_

[Subin Kuttappan Stellal Mary]

I am able to open the file SA.NDVI_QKM.GLCF.2000273.sinus.band2.bin downloaded from the link, using the fopen function.

Following is the command I used to open the file. The file is present in my current MATLAB folder:

>> fileID = fopen('SA.NDVI_QKM.GLCF.2000273.sinus.band2.bin','r')

fileID =

       4

>> A = fread(fileID);

I got A as a 289144475x1 vector.

For checking what is the issue at your side, provide the following info:

1) What are the commands you used?

2) Is the file path proper?

[Flum]

Hello Subin, thanks a lot for your answer! Unfortunately, at the point your answer came, I did not expect anybody would ever deal with the question and forgot to check it again. I also found a semi-satisfying way of opening the file with R, exporting it to another format and then throwing Matlab on it. :) So, from now on, I will use this forum more responsibly and re-check this thread the next time I am dealing with binaries!

Answer 1

[Image Analyst]

It could be you had already opened it, then stopped your script for some reason and then tried to open it again. Or some other program might have put a lock on it because the other program had the file open.