One-dimensional arrays are supported whether as global variables or functions arguments. +Arrays are mapped in SWIG as pointers. But primitive type arrays are automatically converted from/to Scilab matrices.
-Global arrays are wrapped through accessor functions. +Global arrays are manipulated in Scilab through accessor functions. For example with two global arrays x and y:
@@ -650,7 +651,7 @@ void initArrays() %} -Two Scilab functions are generated for each array: a getter _get() and a setter _set(), prefixed by the array name. +
Two Scilab functions are generated for each array: a getter _get() and a setter _set(), prefixed by the array name. Following is an example of use of these functions:
@@ -682,113 +683,76 @@ And this C int array is automatically converted in output to a Scilab double vec- Scilab uses matrices a lot for numerical mathematics and scientific visualization. Supporting matrices makes Scilab more convenient. For example: +Matrices can be implemented in several ways in C, here we focus on matrices implemented with pointer-to-pointer (ex: double**).
-%module example ++These matrices are mapped by default in SWIG as pointers. +There is no automatic conversion with Scilab matrices, for this, the matrix.i library has to be used. +
+ ++ Following is an example with functions working with matrices: +
+ +-+%module example %inline %{ -double **new_matrix() { - int i; +// Returns the matrix [1 2; 3 4]; +double **create_matrix() { double **M; - - M = (double **) malloc(4 * sizeof(double *)); - M[0] = (double *) malloc(16 * sizeof(double)); - - for (i = 0; i < 4; i++) { - M[i] = M[0] + 4 * i; + int i; + M = (double **) malloc(2 * sizeof(double *)); + for (i = 0; i < 2; i++) { + M[i] = (double *) malloc(2 * sizeof(double)); + M[i][0] = 2 * i + 1; + M[i][1] = 2 * i + 2; } return M; } -void set_m(double **M, int i, int j, double val) { - M[i][j] = val; -} - -double get_m(double **M, int i, int j) { +// Gets the item M(i,j) value +double get_matrix(double **M, int i, int j) { return M[i][j]; } -void print_matrix(double **M) { +// Sets the item M(i,j) value to be val +void set_matrix(double **M, int i, int j, double val) { + M[i][j] = val; +} - int i,j; - - for (i = 0; i < 4; i++) { - for (j = 0; j < 4; j++) { - printf("%10g ", M[i][j]); +// Prints a matrix (2,2) to console +void print_matrix(double **M, int nbRows, int nbCols) { + int i, j; + for (i = 0; i < 2; i++) { + for (j = 0; j < 2; j++) { + printf("%3g ", M[i][j]); } printf("\n"); } } -void mat_mult(double **m1, double **m2, double **m3) { - - int i,j,k; - double temp[4][4]; - - for (i = 0; i < 4; i++) - for (j = 0; j < 4; j++) { - temp[i][j] = 0; - for (k = 0; k < 4; k++) - temp[i][j] += m1[i][k] * m2[k][j]; - } - - for (i = 0; i < 4; i++) - for (j = 0; j < 4; j++) - m3[i][j] = temp[i][j]; -} %}When wrapped, it would generate the following function: -
-_wrap_new_matrix(): generate a new matrix. -
-_wrap_set_m(M, i, j, a): set M(i, j) to be value a. -
-_wrap_get_m(M, i, j): get the value of M(i, j). -
-_wrap_print_matrix(M): print the matrix M. -
-_wrap_mat_mult(A, B, C): compute the A * B and the result is stored into C. -
-It can be used like this: +
+ These functions are used like this in Scilab:
---> exec loader.sce +--> m = create_matrix(); ---> x = new_matrix(); ---> for i = 0 : 3; ---> for j = 0 : 3; ---> set_m(x, i, j, i + j); ---> end; ---> end; +--> print_matrix(m); + 1. 2. + 3. 4. ---> print_matrix(y); - 0 1 2 3 - 1 2 3 4 - 2 3 4 5 - 3 4 5 6 ---> y = new_matrix(); ---> for i = 0 : 3; ---> for j = 0 : 3; ---> set_m(y, i, j, i - j); ---> end; ---> end; +--> set_matrix(m, 1, 1, 5.); ---> print_matrix(y); - 0 -1 -2 -3 - 1 0 -1 -2 - 2 1 0 -1 - 3 2 1 0 ---> z = new_matrix(); ---> mat_mult(x, y, z); ---> print_matrix(z); - 14 8 2 -4 - 20 10 0 -10 - 26 12 -2 -16 - 32 14 -4 -22 +--> get_matrix(m, 1, 1) + ans = + + 5.