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fortran

Fortran representation of symbolic expression

Description

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

example

fortran(f,Name,Value) uses additional options specified by one or more Name,Value pair arguments.

Examples

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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 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

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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.

Before R2021a, use commas to separate each name and value, and enclose Name in quotes.

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

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 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