calculate log frequency sweep such that start frequency and stop frequency are always exactly included

3 years ago · 75c2a3c621
1 changed files with 3 additions and 2 deletions
--- a/src/spicelib/analysis/acan.c
+++ b/src/spicelib/analysis/acan.c
@ -86,8 +86,9 @@ ACan(CKTcircuit *ckt, int restart)
                fprintf(stderr, "ERROR: AC startfreq <= 0\n");
                return E_PARMVAL;
            }
-            job->ACfreqDelta =
-                exp(log(10.0)/job->ACnumberSteps);
+            double num_steps = floor(fabs(log10(job->ACstopFreq/job->ACstartFreq))*job->ACnumberSteps);
+            job->ACfreqDelta = exp((log(job->ACstopFreq/job->ACstartFreq))/ num_steps);
+
            break;
        case OCTAVE:
            if (job->ACstartFreq <= 0) {