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(Not recommended) Save optimization expression description


writeexpr is not recommended. Use write instead.

writeexpr(expr) saves a description of the optimization expression expr in a file named expr.txt. Here, expr is the workspace variable name of the expression. If writeexpr cannot construct the file name from the expression, it writes the description to WriteExprOutput.txt instead. writeexpr overwrites any existing file.


writeexpr(expr,filename) saves a description of the optimization expression expr in a file named filename.


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Create an optimization variable and an expression that uses the variable. Save a description of the expression to a file.

x = optimvar('x',3,3);
A = magic(3);
var = sum(sum(A.*x));

The VarExpression.txt file contains the following text:

  8*x(1, 1) + 3*x(2, 1) + 4*x(3, 1) + x(1, 2) + 5*x(2, 2) + 9*x(3, 2) + 6*x(1, 3) + 7*x(2, 3)
+ 2*x(3, 3)

Input Arguments

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Optimization expression, specified as an OptimizationExpression object.

Example: sum(sum(x))

Path to the file, specified as a string or character vector. The path is relative to the current folder. The resulting file is a text file, so the file name typically has the extension .txt.

Example: "../Notes/steel_stuff.txt"

Data Types: char | string


  • To obtain the writeexpr information at the MATLAB® Command Window, use showexpr.

Version History

Introduced in R2017b

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Not recommended starting in R2019b