fix bug in single PE charge

This commit makes sure that when we conolve the single PE charge distribution
with a gaussian we integrate starting at zero since the PDF is zero for q < 0.

2 files changed, 2 insertions, 2 deletions

diff --git a/src/sno_charge.c b/src/sno_charge.c
index 31de608..f96655b 100644
--- a/src/sno_charge.c
+++ b/src/sno_charge.c
@@ -231,7 +231,7 @@ void init_charge(void)
         for (j = 0; j < nq; j++) {
             params[0] = x[j];
             params[1] = i;
-            gsl_integration_cquad(&F, x[j]-QSMEAR_ADC*10/MEAN_HIPT, x[j]+QSMEAR_ADC*10/MEAN_HIPT, 0, 1e-4, w, &result, &error, &nevals);
+            gsl_integration_cquad(&F, fmax(0.0,x[j]-QSMEAR_ADC*10/MEAN_HIPT), x[j]+QSMEAR_ADC*10/MEAN_HIPT, 0, 1e-4, w, &result, &error, &nevals);
             y[j] = result;
         }
         gsl_spline_free(splines[i-1]);
diff --git a/src/test.c b/src/test.c
index 9976f1f..6d7d934 100644
--- a/src/test.c
+++ b/src/test.c
@@ -278,7 +278,7 @@ int test_sno_charge_integral(char *err)
 
     gsl_integration_cquad(&F, -10.0, 1000.0, 0, 1e-9, w, &result, &error, &nevals);
 
-    if (!isclose(result, 1.0, 1e-9, 1e-9)) {
+    if (!isclose(result, 1.0, 1e-9, 1e-3)) {
         sprintf(err, "integral of single PE charge distribution is %.2f", result);
         goto err;
     }