Changeset 6c96f4

Timestamp:

May 21, 2008, 1:42:05 PM (17 years ago)

Author:

Frederik Heber <heber@…>

Children:

f75030

Parents:

a6e314

Message:

lots of small changes

-1 as either freq_start or freq_step lets VibrAlyzer determine necessary start and step values automatically by considering smallest and greatest possible determinably frequencies. Used start and step values are printed.
In parsing temperatures and timesteps counter-1 instead of counter was used as array index.
outer loop over frequency was done in a overly-correct manner (extra j for the loop, now we calculate freq_end and check for that.
command line values of start and step are now multiplied with 2*2*M_PI, so that they match ranges in the plot later.
Parsing of values was checked and is correct.

File:

• util/VibrAlyzer.c (modified) (3 diffs)

util/VibrAlyzer.c

@@ -23 +23 @@
         double *time_steps, *temperatures;      // contain data value pairs
         int counter;            // keeps track of data pairs array size
-        double freq_start, freq_step;   // frequency start and step width (end determined by number of points in temp.file)
+        double freq_start, freq_step, freq_end; // frequency start and step width (end determined by number of points in temp.file)
         char *filename; // filename of temp.file
         char line[255]; // line buffer for parsing the temperature file
-        int i,j;        // runtime variable
+        int i;  // runtime variable
         double result, iresult;         // temporary result value for fourier transformation
         double frequency;               // current frequency during dumb O(N^2) integration
@@ -67 +67 @@
   counter=0;
   while (fgets(line,255, temperature_file)) {
-    sscanf(line,"%lg %lg", &time_steps[counter-1], &temperatures[counter-1]);
+    sscanf(line,"%lg %lg", &time_steps[counter], &temperatures[counter]);
+    //fprintf(stderr, "%lg\t%lg\n", time_steps[counter], temperatures[counter]);
     counter++;
   }
-        // for debugging only: print read values
+  // auto-set good values for start and step based on step range
+  if ((freq_start == -1) || (freq_step == -1)) {
+    // we cannot detect frequencies above twice a time step and not below half the time range
+    freq_start = 1./(fabs(time_steps[counter-1] - time_steps[0])*gauge);  
+    freq_step = ( 1./(fabs(time_steps[1] - time_steps[0])*gauge) - 1./(fabs(time_steps[counter-1] - time_steps[0])*gauge) )/counter;
+    fprintf(stderr, "Using %lg and frequency start and %lg as step size.\n", freq_start/(2.*2.*M_PI), freq_step/(2.*2.*M_PI));
+  } else {
+    freq_start *= (2.*2.*M_PI);
+    freq_step *= (2.*2.*M_PI);  
+  }
+
+  // for debugging only: print read values
         //for(i=0;i<(counter-1);i++) {
         //      printf("%lg\t%lg\n",time_steps[i],temperatures[i]);
         //}
   
+  printf("#frequency(a.u.)\tcos\tsin");
   // discretely integrate over desired frequency range
-        frequency = freq_start;
-        for(j=0;j<(counter-1);j++) {
+  freq_end = freq_start+freq_step*counter-1;
+        for(frequency = freq_start;frequency < freq_end;frequency += freq_step) {
                 result = iresult = 0.;
                 for(i=0;i<(counter-1);i++) {
@@ -87 +100 @@
     // have the correct frequency! 
                 printf("%lg\t%lg\t%lg\n",frequency/(2.*2.*M_PI),result/(counter-1),iresult/(counter-1));
-                frequency += freq_step;
         }