r.surf.random: Added seed option to module (#2930)

OSGeo · Apr 5, 2024 · e592034 · e592034
1 parent 0cd72be
commit e592034
Show file tree

Hide file tree

Showing 3 changed files with 47 additions and 15 deletions.
diff --git a/raster/r.surf.random/main.c b/raster/r.surf.random/main.c
@@ -67,9 +67,12 @@ int main(int argc, char *argv[])
     struct Option *out;
     struct Option *min;
     struct Option *max;
+    struct Option *seed;
     struct Flag *i_flag;
     double min_value;
     double max_value;
+    long seed_value;
+    char *seedptr;
 
     struct History history;
     char title[64];
@@ -97,6 +100,14 @@ int main(int argc, char *argv[])
     max->type = TYPE_DOUBLE;
     max->answer = "100";
 
+    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.");
+
     i_flag = G_define_flag();
     i_flag->key = 'i';
     i_flag->description = _("Create an integer raster map");
@@ -107,6 +118,19 @@ int main(int argc, char *argv[])
     min_value = atof(min->answer);
     max_value = atof(max->answer);
 
+    if (seed->answer) {
+        seed_value = strtol(seed->answer, &seedptr, 10);
+        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(_("Autogenerated random seed set to: %ld"),
+                          seed_value);
+    }
+
     /* We disallow max=5.5 for integer output since there are unclear
      * expectations on what it should do. */
     if (i_flag->answer) {

diff --git a/raster/r.surf.random/randsurf.c b/raster/r.surf.random/randsurf.c
@@ -21,10 +21,6 @@ int randsurf(char *out, double min, double max, int int_map)
     /* open raster maps.                    */
     int row_count, col_count;
 
-    /****** INITIALISE RANDOM NUMBER GENERATOR ******/
-    /* You can set GRASS_RANDOM_SEED for repeatability */
-    G_srand48_auto();
-
     /****** OPEN CELL FILES AND GET CELL DETAILS ******/
     fd_out = Rast_open_new(out, int_map ? CELL_TYPE : DCELL_TYPE);
 

diff --git a/raster/r.surf.random/testsuite/test_min_max.py b/raster/r.surf.random/testsuite/test_min_max.py
@@ -14,8 +14,6 @@
 for details.
 """
 
-import os
-
 import grass.script as gs
 
 from grass.gunittest.case import TestCase
@@ -37,12 +35,9 @@ class MinMaxTestCase(TestCase):
     @classmethod
     def setUpClass(cls):
         """Ensures expected computational region"""
-        os.environ["GRASS_RANDOM_SEED"] = "42"
         # modifying region just for this script
         cls.use_temp_region()
-        # Only 100,000,000 seem to resonably (not 100%) ensure that all values
-        # are generated, so exceeding of ranges actually shows up.
-        cls.runModule("g.region", rows=10000, cols=10000)
+        cls.runModule("g.region", rows=10, cols=10)
 
     @classmethod
     def tearDownClass(cls):
@@ -57,10 +52,9 @@ def test_min_max_double(self):
         """Check to see if double output has the expected range"""
         min_value = -3.3
         max_value = 5.8
-        # arbitrary, but with more cells, we expect higher precision
         precision = 0.00001
         self.assertModule(
-            "r.surf.random", min=min_value, max=max_value, output=self.output
+            "r.surf.random", min=min_value, max=max_value, output=self.output, seed=42
         )
         self.assertRasterExists(self.output, msg="Output was not created")
         self.assertRasterMinMax(
@@ -71,7 +65,7 @@ def test_min_max_double(self):
         )
         self.assertRasterFitsInfo(
             raster=self.output,
-            reference=dict(min=min_value, max=max_value),
+            reference=dict(min=-3.20423, max=5.68621),
             precision=precision,
             msg="Output min and max too far from parameters",
         )
@@ -84,7 +78,12 @@ def test_min_max_int(self):
         max_value = 13
         precision = 0
         self.assertModule(
-            "r.surf.random", min=min_value, max=max_value, output=self.output, flags="i"
+            "r.surf.random",
+            min=min_value,
+            max=max_value,
+            output=self.output,
+            seed=42,
+            flags="i",
         )
         self.assertRasterExists(self.output, msg="Output was not created")
         self.assertRasterMinMax(
@@ -105,14 +104,27 @@ def test_double_params_with_int(self):
         min_value = -3.3
         max_value = 5.8
         self.assertModuleFail(
-            "r.surf.random", min=min_value, max=max_value, output=self.output, flags="i"
+            "r.surf.random",
+            min=min_value,
+            max=max_value,
+            output=self.output,
+            seed=42,
+            flags="i",
         )
 
     def test_min_greater_than_max(self):
         """Check if minimum greater than maximum is refused"""
         min_value = 10
         max_value = 5.8
         self.assertModuleFail(
+            "r.surf.random", min=min_value, max=max_value, output=self.output, seed=42
+        )
+
+    def test_auto_seed(self):
+        """Check if random seed is generated without seed"""
+        min_value = -3.3
+        max_value = 5.8
+        self.assertModule(
             "r.surf.random", min=min_value, max=max_value, output=self.output
         )