Evaluate MATLAB expression in specified workspace
Security Considerations: When calling
evalin with untrusted user input, validate the input to avoid
unexpected code execution. Examples of untrusted user input are data coming from a user you
might not know or from a source you have no control over. If you need to address this
concern, consider these approaches:
Validate inputs to
evalin. First, search for allowed
operations. Then, if you find other operations, disallow execution.
evalin with an alternative. For more
information, see Alternatives to the eval Function.
Performance Considerations: In most cases, using the
evalin function is also less efficient than using other
MATLAB functions and language constructs, and the resulting code can be more
difficult to read and debug. Consider using an alternative to
evalin function to get the value
of a variable in the MATLAB base workspace and store it in a new variable.
var as the 5-by-5 matrix returned by the
var = magic(5);
Get the value of the variable
var in the MATLAB base workspace and store it in the variable
v = evalin('base','var')
v = 17 24 1 8 15 23 5 7 14 16 4 6 13 20 22 10 12 19 21 3 11 18 25 2 9
workspace— Workspace in which to evaluate expression
Workspace in which to evaluate expression, specified as
The MATLAB base workspace is the workspace that is seen from the MATLAB command line (when not in the debugger). The caller workspace is the workspace of the function that called the currently running function. The base and caller workspaces are equivalent in the context of a function that is invoked from the MATLAB command line.
expression— Expression to evaluate
Expression to evaluate, specified as a character vector or string scalar.
expression must be a valid MATLAB expression and must not include any MATLAB keywords. To determine whether a word is a MATLAB keyword, use the
output1,...,outputN— Outputs from evaluated expression
Outputs from evaluated expression, returned as any MATLAB data type.
evalin('caller',expression) finds only
variables in the caller's workspace; it does not find
functions in the caller. For this reason, you cannot
evalin to construct a handle to a function that is
defined in the caller.
evalin cannot be used recursively to evaluate an
expression. For example, statement
If you use
evalin within an anonymous function, nested
function, or function that contains a nested function, the evaluated
expression does not create any variables.
To allow the MATLAB parser to perform stricter checks on your code and avoid untrapped
errors and other unexpected behaviors, do not include output arguments in the
input to the
evalin function. For example, the statement
evalin('base',['output = ',expression]) is not
Instead, specify output arguments to the
to store the results of the evaluated expression. For example:
output = evalin('base',expression)