write

Save optimization object description

Syntax

write(obj)

write(obj,filename)

Description

Use write to save the description of an optimization object.

Tip

For the full workflow, see Problem-Based Optimization Workflow or Problem-Based Workflow for Solving Equations.

write(obj) saves a description of the optimization object obj in a file named obj.txt. Here, obj is the workspace variable name of the optimization object. If write cannot construct the file name from the expression, it writes the description to WriteOutput.txt instead. write overwrites any existing file. If the object description is small, consider using show instead to display the description at the command line.

write(obj,filename) saves a description of obj in a file named filename.

Examples

Save Expression Description

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));
write(var)

write creates a file named var.txt in the current folder. The 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)

Save the expression in a file named 'VarExpression.txt' in the current folder.

write(var,"VarExpression.txt")

The VarExpression.txt file contains the same text as var.txt.

Input Arguments

obj — Optimization object

OptimizationProblem object | EquationProblem object | OptimizationExpression object | OptimizationVariable object | OptimizationConstraint object | OptimizationEquality object | OptimizationInequality object

Optimization object, specified as one of the following:

• OptimizationProblem object — write(obj) saves a file containing the variables for the solution, objective function, constraints, and variable bounds.

• EquationProblem object — write(obj) saves a file containing the variables for the solution, equations for the solution, and variable bounds.

• OptimizationExpression object — write(obj) saves a file containing the optimization expression.

• OptimizationVariable object — write(obj) saves a file containing the optimization variables. The saved description does not indicate variable types or bounds; it includes only the variable dimensions and index names (if any).

• OptimizationConstraint object — write(obj) saves a file containing the constraint expression.

• OptimizationEquality object — write(obj) saves a file containing the equality expression.

• OptimizationInequality object — write(obj) saves a file containing the inequality expression.

filename — Path to file

string | character vector

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

Version History

Introduced in R2019b