MATLAB API Reference

Below are the main commands you can use in your MATLAB scripts to interact with MDSplus, i.e., use MATLAB to retrieve from and put data into MDSplus trees. See the main MATLAB guide for more information on how to set up MATLAB to work with MDSplus.

mdsconnect(SERVER_NAME)

Makes a thin client connection to the specified MDSplus data server. Will cause subsequent invocations of mdsopen, mdsvalue, mdsput, and mdsclose to be executed remotely on the specified host. mdsdisconnect will destroy this connection, reverting the above described routines to their local behaviors.

Parameters
SERVER_NAME	your host/server name goes here
Type	Matlab string
Usage	mdsconnect('name_of_mdsplus_server')
Returns	Status

>> mdsconnect('alcdata-archives')  
ans =
     1

mdsclose()

Closes currently active tree.

Parameters
Name	-
Type	-
Usage	mdsclose()
Returns	Status

mdsdisconnect()

Disconnect from a remote mdsplus data server.

Parameters
Name	-
Type	-
Usage	mdsdisconnect()
Returns	Status

mdsInfo(USE_PYTHON=false)

This is an internal function and is not recommended for general usage. This function can be called to activate the MDSplus Python bridge, but the best way to do that is with mdsUsePython (see also: mdsUsePython), therefore mdsInfo is an unnecessary step prior to calling other functions such as mdsopen, mdsconnect, etc.

mdsopen(EXPRESSION, SHOT)

Opens a tree or, if specified, a connection to a remote MDSplus data server and a tree.

Parameters
EXPRESSION	can be a tree name (MATLAB string)
	deprecated and might be removed: can also be a server followed by a tree name if separated by double colons (for example: SERVER_NAME::TREE)
SHOT	shot number (Int)
Usage	mdsopen('cmod', 1090909009)
	mdsopen('alcdata-archives::cmod', 1090909009)
Returns	Shot number, Status

>> mdsopen('cmod', 1090909009)
>> a=mdsvalue(':ELECTRONS:TSTART')
a =
  single
    -4
>> [a, status]=mdsvalue(':ELECTRONS:TSTART')
a =
  single
    -4
status =
     1

mdsput(NODE, EXPRESSION, VARARGIN)

Puts data into an MDSplus tree node. This routine uses the java or python interface, which you must choose with mdsUsePython (see also: mdsUsePython).

Parameters
NODE	Matlab string
EXPRESSION	Matlab string
VARARGIN	Matlab string
Returns	Status
Usage	see below

>> sample = '"something"'
sample =
    '"acq_address"'
>> mdsput(':ACQ2106_122:ADDRESS', sample)
ans =
     1
>> a=mdsvalue(':ACQ2106_122:ADDRESS')
a =
    "acq_address"
>>
>> mdsput(':TEST', '[1.1, 2.2]')
ans =
     1
>> a=mdsvalue(':TEST')
a =
  2x1 single column vector
    1.1000
    2.2000

>> mdsUsePython(false)
>> x = (0:1000)/50;
>> y = sin(x);
>> mdsput(':signal','BUILD_SIGNAL($1,,$2)', y, x)
ans =
     1
>>

mdstcl(/COMMAND)

Run TCL command or open a TCL prompt. This function provides Matlab with the same MDSTCL interface as IDL. (See also: MDSTCL)

• If a TCL command is passed to this routine, it will execute, output the response, if any, to the terminal, and return to the MATLAB prompt.

• If this routine is called without a TCL command, then it will go into a loop of prompting for, executing TCL commands, and outputting the responses, until exit is entered.

Parameters	Type
COMMAND	String
Returns	(nothing returned)
Usage	see below

>> mdstcl('set tree cmod')
>> mdstcl('dir electrons:*')
\ELECTRONS::TOP
 :ENG_ENCODER  :TSTART
Total of 2 nodes.

>> mdstcl()
TCL> >>

mdsvalue(expression, varargin)

Call to evaluate MDSplus expressions, i.e., TDI commands.

Parameters	Type
expression	MATLAB string
varargin	MATLAB string
Returns	Result, Status
Usage	mdsvalue('TDI_EXPRESSION')

>> [a, status]=mdsvalue(':ELECTRONS:TSTART')
a =
  single
    -4
status =
     1

>> sample='"something"'
sample =
    '"something"'
>> mdsput(':ACQ2106_122:ADDRESS', sample)

mdsUsePython(USE_PYTHON=true)

This function allows switching between using the Java bridge and the Python bridge. The default (false) is Java.

Parameters
Arguments	true (1), false (0)
Type	Matlab boolean
Returns	(nothing returned)
Usage	mdsUsePython(true) or mdsUsePython(1) for Python
	mdsUsePython(false) or mdsUsePython(0) for Java

>> mdsUsePython()
>> i=mdsInfo()
i =
  struct with fields:
           isConnected: 1
            connection: [1x1 MDSplus.Connection]
         connectedHost: 'alcdata-archives'
             usePython: 1
    isPythonConnection: 0
                 ispy2: 0
>>

Please see the list of versions of Python compatible with MATLAB.