star-wf

commit f4c603c2a4cd4782f56f3d911c403aec9d3fba9a
parent 6bf96511daec4f6f485dbc8e31c8ed8e778260c1
Author: Vincent Forest <vincent.forest@meso-star.com>
Date:   Sun, 10 Mar 2024 10:21:59 +0100

Update default tabulation range for H

The minimum lower limit is set at 7.5e-3. Below this limit, the
calculation of H falls into numerical uncertainties that cause it to
oscillate and is therefore not strictly increasing as it should (H is a
cumulative).

Reducing the tabulation interval to this limit is not really an issue,
since the tabulation is used for the inversion of H(x) in [0, 1[. And H
of 7.5e-3 is 4.32987e-14. Put another way, below this minimum, some
people try to invert a value whose corresponding argument is negligible
in relation to the probability of its occurrence (of the order of
1e-14).

Diffstat:
M
src/swf.h
 | 
2
+-

1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/src/swf.h b/src/swf.h
@@ -40,7 +40,7 @@ struct swf_H_tabulate_args {
   double delta_x;
   struct mem_allocator* allocator; /* NULL <=> use default allocator */
 };
-#define SWF_H_TABULATE_ARGS_DEFAULT__ {0, 3.88, 1e-5, NULL}
+#define SWF_H_TABULATE_ARGS_DEFAULT__ {7.5e-3, 3.8, 1e-5, NULL}
 static const struct swf_H_tabulate_args SWF_H_TABULATE_ARGS_DEFAULT =
   SWF_H_TABULATE_ARGS_DEFAULT__;