Read write binary file matlab

Documentation Help Center Documentation. The binary file is indicated by the file identifier, fileID. Use fopen to open the file and obtain the fileID value. When you finish reading, close the file by calling fclose fileID. Values are interpreted in the file according to the form and size described by precision.

You can use this syntax with any of the input arguments of the previous syntaxes. Write a nine-element vector to a sample file, nine. Read all the data in the file into a vector of class double. By default, fread reads a file 1 byte at a time, interprets each byte as an 8-bit unsigned integer uint8 , and returns a double array.

Create a file named doubledata. Open the file, doubledata. Specify that the source data is class double. Create a file named nine. Write the data as uint16 values. Read the first six values into a 3-by-2 array. Specify that the source data is class uint Read two values at a time, and skip one value before reading the next values.

Because the data is class uint16 , one value is represented by 2 bytes. Therefore, specify the skip argument as 2. Return to the beginning of the file using frewind. If you read 4 bits at a time on a little-endian system, your results appear in the wrong order. Read the data 4 bits at a time as before, but specify a big-endian ordering to display the correct results. File identifier of an open binary file, specified as an integer.

Before reading a file with fread , you must use fopen to open the file and obtain the fileID. Dimensions of the output array, A , specified as Inf , an integer, or a two-element row vector. Class and size in bits of the values to read, specified as a character vector or a string scalar in one of the following forms. Optionally the input specifies the class of the output matrix, A. Read N values before skipping the number of bytes specified by the skip argument.

The following table shows possible values for source and output. Find centralized, trusted content and collaborate around the technologies you use most.

Connect and share knowledge within a single location that is structured and easy to search. Trying to do the simplest thing ever. Write a number in QT in binary mode unsigned 16 and read the file in matlab. I use Append mode since I will be adding numbers to the file in the future But can't seem to do this right. The problem is really simple: you are writing big-endian data MSB comes first , but Matlab by default expects little endian data.

The fix is simple:. QDataStream is not really meant to create streams that are portable across different applications. It is meant to be portable across different OS and Qt versions, but always consumed by Qt. The format is not guaranteed to be stable, so it could work today but break tomorrow. From the docs:. QDataStream's binary format has evolved since Qt 1. When inputting or outputting complex types, it's very important to make sure that the same version of the stream version is used for reading and writing.

If you want to share data, use an output format that is intended for sharing, like XML, Json, or, in a simple case like this, just write out the number as a ANSI string to a text file. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Collectives on Stack Overflow. Learn more. Writing binary files in QT and reading in matlab Ask Question. Asked 9 years, 6 months ago.

Active 9 years, 4 months ago. Viewed 6k times. Thank you! Don't byte swap like that. Maurice Maurice 1. Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password. Post as a guest Name. Email Required, but never shown. The Overflow Blog. Podcast Making Agile work for data science. Stack Gives Back Featured on Meta. New post summary designs on greatest hits now, everywhere else eventually. Related Hot Network Questions. Question feed.