Changeset 2773c66 in sasmodels for sasmodels/kernel_iq.c

Timestamp:

Sep 8, 2018 10:29:05 AM (6 years ago)

Author:

Torin Cooper-Bennun <torin.cooper-bennun@…>

Branches:

master, core_shell_microgels, magnetic_model, ticket-1257-vesicle-product, ticket_1156, ticket_1265_superball, ticket_822_more_unit_tests

Children:

ba51e00

Parents:

b763f9d (diff), c88f983 (diff)
Note: this is a merge changeset, the changes displayed below correspond to the merge itself.
Use the (diff) links above to see all the changes relative to each parent.

Message:

Merge branch 'beta_approx' into beta_approx_new_R_eff

File:

• sasmodels/kernel_iq.c (modified) (1 diff)

sasmodels/kernel_iq.c

@@ -192 +192 @@
     QACRotation *rotation,
     double qx, double qy,
-    double *qa_out, double *qc_out)
+    double *qab_out, double *qc_out)
 {
+    // Indirect calculation of qab, from qab^2 = |q|^2 - qc^2
     const double dqc = rotation->R31*qx + rotation->R32*qy;
-    // Indirect calculation of qab, from qab^2 = |q|^2 - qc^2
-    const double dqa = sqrt(-dqc*dqc + qx*qx + qy*qy);
-
-    *qa_out = dqa;
+    const double dqab_sq = -dqc*dqc + qx*qx + qy*qy;
+    //*qab_out = sqrt(fabs(dqab_sq));
+    *qab_out = dqab_sq > 0.0 ? sqrt(dqab_sq) : 0.0;
     *qc_out = dqc;
 }