fortran

R2026b

Fortran representation of symbolic expression

Syntax

fortran(f)

fortran(f,Name=Value)

Description

fortran(f) returns Fortran code for the symbolic expression f.

fortran(f,Name=Value) uses additional options specified by one or more name-value arguments.

Examples

Generate Fortran Code from Symbolic Expression

Generate Fortran code from the symbolic expression log(1+x).

syms x
f = log(1+x);
fortran(f)

ans =
    '      t0 = log(x+1.0D0)'

Generate Fortran code for the 3-by-3 Hilbert matrix.

H = sym(hilb(3));
fortran(H)

ans =
    '      H(1,1) = 1.0D0
           H(1,2) = 1.0D0/2.0D0
           H(1,3) = 1.0D0/3.0D0
           H(2,1) = 1.0D0/2.0D0
           H(2,2) = 1.0D0/3.0D0
           H(2,3) = 1.0D0/4.0D0
           H(3,1) = 1.0D0/3.0D0
           H(3,2) = 1.0D0/4.0D0
           H(3,3) = 1.0D0/5.0D0'

Write Fortran Code to File with Comments

Write generated Fortran code to a file by specifying the File option. When writing to a file, fortran optimizes the code using intermediate variables named t0, t1, .… Include comments in the file by using the Comments option.

syms x
f = diff(tan(x));
fortran(f,File='fortrantest')

      t0 = tan(x)**2+1.0D0

Include the comment Version: 1.1. Comment lines must be shorter than 71 characters to conform with Fortran 77.

fortran(f,File='fortrantest',Comments='Version: 1.1')

*Version: 1.1
      t0 = tan(x)**2+1.0D0

Input Arguments

f — Symbolic input

symbolic expression

Symbolic input, specified as a symbolic expression.

Name-Value Arguments

Specify optional pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

Example: fortran(x^2,File='fortrancode',Comments='V1.2')

File — File to write to

character vector | string

File to write to, specified as a character vector or string. When writing to a file, fortran optimizes the code using intermediate variables named t0, t1, ....

Comments — Comments to include in file header

character vector | cell array of character vectors | string vector

Comments to include in the file header, specified as a character vector, cell array of character vectors, or string vector. Comment lines must be shorter than 71 characters to conform with Fortran 77.

Tips

• MATLAB^® is left-associative while Fortran is right-associative. If ambiguity exists in an expression, the fortran function must follow MATLAB to create an equivalent representation. For example, fortran represents a^b^c in MATLAB as (a**b)**c in Fortran.

Version History

Introduced before R2006a