r.surf.fractal: Added seed option and -s flag to module

raster/r.surf.fractal/main.c

@@ -28,6 +28,10 @@ int main(int argc, char *argv[])
     struct Option *rast_out;   /* Structure for output raster     */
     struct Option *frac_dim;   /* Fractal dimension of surface.   */
     struct Option *num_images; /* Number of images to produce.    */
+    struct Option *seed;
+
+    long seed_value;
+    char *seedptr;
 
     G_gisinit(argv[0]); /* Link with GRASS interface.      */
 
@@ -54,9 +58,32 @@ int main(int argc, char *argv[])
     num_images->required = NO;
     num_images->answer = "0";
 
+    seed = G_define_option();
+    seed->key = "seed";
+    seed->type = TYPE_INTEGER;
+    seed->required = NO;
+    seed->label = _("Seed for random number generator");
+    seed->description = _("The same seed can be used to obtain same results"
+                          " or random seed can be generated by other means.");
+
     if (G_parser(argc, argv)) /* Performs the prompting for      */
         exit(EXIT_FAILURE);   /* keyboard input.                 */
 
+    /****** INITIALISE RANDOM NUMBER GENERATOR ******/
+    if (seed->answer) {
+        seed_value = atol(seed->answer);
+        G_srand48(seed_value);
+        G_verbose_message(_("Read random seed from %s option: %ld"), seed->key,
+                          seed_value);
+    }
+    else {
+        /* default as it used to be */
+        seed_value = G_srand48_auto();
+        G_verbose_message(_("Warning set option seed. Generated "
+                            "random seed (-s): %ld"),
+                          seed_value);
+    }
+
     rast_out_name = rast_out->answer;
     sscanf(frac_dim->answer, "%lf", &H);
     H = 3.0 - H;

raster/r.surf.fractal/spec_syn.c

@@ -42,9 +42,6 @@ int specsyn(double *data[2], /* Array holding complex data to transform. */
     double phase, rad, /* polar coordinates of Fourier coeff.  */
         *temp[2];
 
-    /* You can set GRASS_RANDOM_SEED for repeatability */
-    G_math_srand_auto(); /* Reset random number generator.       */
-
     temp[0] = (double *)G_malloc(nn * nn * sizeof(double));
     temp[1] = (double *)G_malloc(nn * nn * sizeof(double));
 

raster/r.surf.fractal/testsuite/test_r_surf_fractal.py

@@ -0,0 +1,110 @@
+#!/usr/bin/env python3
+
+"""
+MODULE:    Test of r.surf.fractal
+
+AUTHOR(S): Shashank Shekhar Singh <shashankshekharsingh1205 gmail com>
+
+PURPOSE:   Test fractal surface generation with r.surf.fractal module
+
+COPYRIGHT: (C) 2024 by Shashank Shekhar Singh and the GRASS Development Team
+
+This program is free software under the GNU General Public
+License (>=v2). Read the file COPYING that comes with GRASS
+for details.
+"""
+
+import os
+
+import grass.script as gs
+
+from grass.gunittest.case import TestCase
+from grass.gunittest.main import test
+
+
+class FractalTestCase(TestCase):
+    """Test case for r.surf.fractal"""
+
+    # Raster map name to be used as output
+    output = "fractal_result"
+
+    @classmethod
+    def setUpClass(cls):
+        """Set up necessary environment"""
+        # Set up temporary computational region
+        cls.use_temp_region()
+        # Only 100,000,000 seem to reasonably (not 100%) ensure that all values
+        # are generated, so exceeding of ranges actually shows up.
+        cls.runModule("g.region", rows=10000, cols=10000)
+
+    @classmethod
+    def tearDownClass(cls):
+        """Clean up temporary environment"""
+        cls.del_temp_region()
+
+    def tearDown(self):
+        """Remove the output created from the module after each test"""
+        self.runModule("g.remove", flags="f", type="raster", name=[self.output])
+
+    def test_default_settings(self):
+        """Test with default settings"""
+        self.assertModule("r.surf.fractal", output=self.output)
+
+    def test_fractal_dimension(self):
+        """Test with specified fractal dimension"""
+        fractal_dim = 2.05  # Example fractal dimension value
+        self.assertModule(
+            "r.surf.fractal",
+            dimension=fractal_dim,
+            output=self.output,
+        )
+
+    def test_num_images(self):
+        """Test with specified number of intermediate images"""
+        num_images = 5  # Example number of intermediate images
+        self.assertModule(
+            "r.surf.fractal",
+            number=num_images,
+            output=self.output,
+        )
+
+    def test_random_seed(self):
+        """Test with specified random seed"""
+        seed_value = 12345  # Example random seed value
+        self.assertModule(
+            "r.surf.fractal",
+            seed=seed_value,
+            output=self.output,
+        )
+
+    def test_generate_random_seed(self):
+        """Test with flag to generate random seed"""
+        self.assertModule(
+            "r.surf.fractal",
+            flags="s",
+            output=self.output,
+        )
+
+    def test_invalid_fractal_dimension(self):
+        """Test with invalid fractal dimension"""
+        invalid_dim = 1.5  # Example invalid fractal dimension value
+        # Ensure that the module fails with an error message
+        self.assertModuleFail(
+            "r.surf.fractal",
+            dimension=invalid_dim,
+            output=self.output,
+        )
+
+    def test_invalid_seed_value(self):
+        """Test with invalid random seed value"""
+        invalid_seed = "abc"  # Example invalid random seed value
+        # Ensure that the module fails with an error message
+        self.assertModuleFail(
+            "r.surf.fractal",
+            seed=invalid_seed,
+            output=self.output,
+        )
+
+
+if __name__ == "__main__":
+    test()