mat Plugin

• Prerequisites

Download the MATLAB Runtime for your operating system: Mathworks website.

Download and install MATLAB Compiler Runtime R2016a:

wget https://ssd.mathworks.com/supportfiles/downloads/R2016a/deployment_files/R2016a/installers/glnxa64/MCR_R2016a_glnxa64_installer.zip
unzip MCR_R2016a_glnxa64_installer.zip -d matlabFile
cd matlabFile
./install -mode silent -agreeToLicense  yes  -destinationFolder  /home/Matlab

Please make sure the file libDolphinDB.so is under the GCC search path before compilation. You can configure with the following command:

cd <DolphinDBServerDir>
export LD_LIBRARY_PATH=/home/Matlab/v901/bin/glnxa64:$LD_LIBRARY_PATH

Then load the plugin in DolphinDB:

./dolphindb
login(`admin,`123456)
loadPlugin("<PluginDir>/mat/build/PluginMat.txt");

You can compile the mat plugin with CMake and G++ on Linux.

Syntax

mat::extractMatSchema(file)

Parameters

• file: A STRING scalar, indicating the absolute path where the .mat file is located.

Details

Generate the schema of the data set in the .mat file. It contains 2 columns: column name and data type.

Example

schema=mat::extractMatSchema("<FileDir>/simple.mat");

Syntax

mat::loadMat(file, [schema])

Parameters

• file: A STRING scalar, indicating the absolute path where the .mat file is located.

• schema: a table containing the names and data types of columns. You can modify the data type as appropriate.

Details

Return a dictionary. The key is a string of variable names; The value is the corresponding matrix or vector. When converting a character array, it returns a STRING vector.

Examples

schema=mat::extractMatSchema("<FileDir>/simple.mat");
ret=mat::loadMat("<FileDir>/simple.mat",schema);

Syntax

mat::convertToDatetime(data)

Parameters

• data: The variable to be converted. It can be a scalar, vector, or matrix of double type.

Details

Convert the temporal variables in the .mat file to DolphinDB DATETIME values.

Examples

schema=mat::extractMatSchema("<FileDir>/simple.mat");
ret=loadMat("<FileDir>/simple.mat",schema);
//t_num in simple.nat is a temporal variable of double type
ret=mat::convertToDatetime(ret[`t_num]);

Syntax

mat::writeMat(file, varName, data)

Parameters

• file: a STRING scalar indicating the file name

• varName: a STRING scalar indicating the corresponding variable name after being written.

• data: a matrix to which the data is written. It is of bool, char, short, int, long, float, or double type.

Details

Write a matrix to a .mat file.

Examples

data = matrix([1, 1, 1], [2, 2, 2]).float()
mat::writeMat("var.mat", "var1", data)

• All data types in DolphinDB are signed types. To avoid data type overflow, unsigned types are converted to higher-level signed types. For example, unsigned CHAR is converted to signed SHORT, unsigned SHORT is converted to signed INT, etc. 64-bit unsigned types cannot be converted.

• Unsigned long long types are not supported in DolphinDB. If the data type in a .mat file is bigint unsigned, you can specify schema of method loadMat as DOUBLE or FLOAT.

• The smallest value of integral types in DolphinDB is NULL, including -128 (CHAR), -32,768 (SHORT), -2,147,483,648 (INT) and -9,223,372,036,854,775,808 (LONG).

• NaN and Inf values in MATLAB are converted to DolphinDB NULL values.