ccode

R2026b

C code representation of symbolic expression

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Syntax

ccode(f)
ccode(f,Name=Value)

Description

ccode(f) returns C code for the symbolic expression f.

example

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

example

Examples

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

syms x
f = log(1+x);
ccode(f)
ans =
    '  t0 = log(x+1.0);'

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

H = sym(hilb(3));
ccode(H)
ans =
    '  H[0][0] = 1.0;
       H[0][1] = 1.0/2.0;
       H[0][2] = 1.0/3.0;
       H[1][0] = 1.0/2.0;
       H[1][1] = 1.0/3.0;
       H[1][2] = 1.0/4.0;
       H[2][0] = 1.0/3.0;
       H[2][1] = 1.0/4.0;
       H[2][2] = 1.0/5.0;'

Because generated C code initializes only non-zero elements, you can efficiently initialize arrays by setting all elements to 0 directly in your C code. Then, use the generated C code to initialize only nonzero elements. This approach enables efficient initialization of matrices, especially sparse matrices.

Initialize the 3-by-3 identity matrix. First initialize the matrix with all elements set to 0 in your C code. Then use the generated C code to initialize the nonzero values.

I3 = sym(eye(3));
I3code = ccode(I3)
I3code =
    '  I3[0][0] = 1.0;
       I3[1][1] = 1.0;
       I3[2][2] = 1.0;'

Write C code to the file ccodetest.c by specifying the File option. When writing to a file, ccode optimizes the code by using intermediate variables named t0, t1, and so on.

syms x
f = diff(tan(x));
ccode(f,File='ccodetest.c')
  t0 = pow(tan(x),2.0)+1.0;

Include the comment Version: 1.1 in the file by using the Comments option. ccode uses block comments.

ccode(f,File='ccodetest.c',Comments='Version: 1.1')
  /*
  Version: 1.1
  */
  t0 = pow(tan(x),2.0)+1.0;

Input Arguments

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Symbolic input, specified as a symbolic expression.

Name-Value Arguments

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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: ccode(x^2,File='ccode.c',Comments='V1.2')

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

Comments to include in the file header, specified as a character vector, cell array of character vectors, or string vector. Because ccode uses block comments, the comments must not contain /* or */.

Tips

  • To generate optimized C or C++ code from a symbolic expression, especially for a large expression, you can use the MATLAB® Coder™ app instead of using the ccode function. This way, the generated code is better integrated into the MATLAB ecosystem. First, convert the symbolic expression to a deployable MATLAB function using matlabFunction. Then, generate C or C++ code from the MATLAB function using the MATLAB Coder app. For an example, see Generate C Code from Symbolic Expressions Using the MATLAB Coder App.

Version History

Introduced before R2006a

See Also

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