How can I store large strings in an array?

Dear Matlab community,

I need to store large strings coming from fread in an array. With a conventional array, this fails with the "Out of memory." error.

I am not really into this topic but for handling large data sets I found two possible solutions which both do apparently not work for my situation:

1) Using matfile: This works great for arrays of numbers, but trying to use strings with a command like

matfileObj.stringArray(i) = char(fread(...));

results in the error "... is of type string. To use ... load the entire variable." However, I am not able to do this for the above-mentioned lack of memory.

2) Using tall: Unfortunately, the file that I work on is in a very ugly binary format that I think can't connect with a datastore. I could, however, initialise a string array of the needed length and generate a tall array from this. But now it seems I can't replace the initialisation strings with the real data; even the command

tallStringArray(i) = "";

fails with "For A(m,n,...) = B, m must be either a colon (:) or a tall logical vector." So apparently, I can't change single entries in the tall array.

Do you have any idea how I can store these large strings?

Many thanks for sharing your thoughts,

Ed

[Fangjun Jiang]

What is the source? fread() from a large text file? It is possible to store the whole text in a string. What is the size?

[Ed Frank]

fread() from a binary file, converted to a string. This string has to be put in a string array, after this the next string is read from the file, put in the array and so on. The strings' length is known, but differs between the strings.

[John D'Errico]

You have large strings of varying sizes? Then learn about cell arrays, which can store them without wasting space because some are larger than others. If you use a regular array, then the array needs to be rectangular, so is far less effcieitn in terms of memory.