Fortran: Difference between revisions

Fortran (edit)

Revision as of 04:56, 13 July 2020

102 bytes added , 13 July 2020

→‎C++ function: Update function to work with Octave 5.2.0+

Siko1056

Bureaucrats, Administrators

1,847

edits

@@ Line 8: / Line 8: @@
 === C++ function ===
-{{Code|octave_file_io.cc: C++ function to load a matrix from an ASCII file in Octave native format|<syntaxhighlight lang="C" style="font-size:13px">
+{{Code|octave_file_io.cc: C++ function to load a matrix from an ASCII file in Octave native format|<syntaxhighlight lang="CC">
+// Octave header
+#include <octave/oct.h>
+#include <octave/ls-mat-ascii.h>
+// Custom header containing the C compatible interface
 #include <octave_file_io.h>
+//! Load a single matrix, stored in ASCII format, from a data file.
+//!
+//! @param file_name name of the data file.
+//! @param data pointer to the read-in matrix stored as fortran vector
+//!             (column-major order).
+//! @param numel number of elements in @p data.
-#include <octave/oct.h>
+int octave_load (const char* file_name, double** data, int* numel)
-#include <octave/ov.h>
-#include <fstream>
-#include <ls-oct-ascii.h>
-#include <octave/octave.h>
-#include <octave/parse.h>
-#include <octave/toplev.h>
-#include <octave/load-save.h>
-#include <octave/oct-map.h>
-#include <cstring>
-int octave_load (const char* filename, const char* varname, double** data, int* numel)
 {
+   // Define variable to hold the read data.
-   string_vector argv (1);
+   octave_value read_data;
-  load_save_format format = LS_ASCII;
-   install_types ();
+   // Read a plain ASCII matrix from data file.
-  argv(0) = varname;
+   std::ifstream in_file_stream (file_name, std::ios::binary);
+  read_mat_ascii_data (in_file_stream, file_name, read_data);
-   std::ios::openmode mode = std::ios::in | std::ios::binary;
+   in_file_stream.close ();
-   std::string fname (filename);
-   std::ifstream file (fname.c_str (), mode);
+   // Convert read data to numerical array (matrix).
+   NDArray A = read_data.array_value ();
-  octave_scalar_map m = do_load (file, fname, format, oct_mach_info::flt_fmt_unknown,
-                                 false, false, true, argv, 0, 1, 1).scalar_map_value ();
-   file.close ();
+   // Extract number of elements in matrix A.
+  *numel = A.numel ();
-   Array<double> M = m.contents (varname).array_value ();
+   // Allocate memory to pointer to returned values.
-  if (error_state)
+  *data  = (double*) malloc (A.numel () * sizeof (double));
-    return -1;
-   *data = (double*) malloc (M.numel () * sizeof (double));
+   // Copy the content of matrix A to data structure Fortran can handle.
-  *numel = M.numel ();
+  memcpy (*data, A.fortran_vec (), A.numel () * sizeof (double));
-  memcpy (*data, M.fortran_vec (), *numel * sizeof (double));
+   return 0;
-   return 0;
 }
 </syntaxhighlight>}}
 === Header file ===