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ccode

C code representation of symbolic expression

Syntax

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

Description

example

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 pair arguments.

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')
  t2 = tan(x);
  t0 = t2*t2+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
*/
  t2 = tan(x);
  t0 = t2*t2+1.0;

Input Arguments

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Symbolic input, specified as a symbolic expression.

Name-Value Pair Arguments

Specify optional comma-separated pairs of Name,Value arguments. Name is the argument name and Value is the corresponding value. Name must appear inside single quotes (' '). You can specify several name and value pair arguments in any order as Name1,Value1,...,NameN,ValueN.

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

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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 */.

Introduced before R2006a

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