Changeset 14801

Timestamp:

01/31/13 11:49:13 (12 years ago)

Author:

tbretz

Message:

Display compression ratio with higher precision, added an example algorithm to compress the data slightly better (~4%)

File:

• trunk/FACT++/src/zfits.cc (modified) (5 diffs)

trunk/FACT++/src/zfits.cc

@@ -160 +160 @@
 
             // If the column is the data, preprocess the data
+            /*
             if (it->second.name=="Data")
-            { /*
-                // e.g. subtract the median (note that this is just
-                // to test the properties of the compression, because
-                // it re-sorts the real data and does not keep the
-                // subtracted offset in the output
-                int n = 30;
-                vector<int16_t> med(1440*n);
-                for (int i=0; i<1440*n; i++)
+            {
+                int16_t *end = ptr+1440*300-2-300%2;
+                int16_t *beg = ptr;
+
+                while (end>=beg)
                 {
-                    int16_t *chunk = ptr+i*300/n;
-                    sort(chunk, chunk+300/n);
-
-                    med[i] = chunk[300/n/2];
-
-                    for (int j=0; j<300/n; j++)
-                        chunk[j] -= med[i];
+                    const int16_t avg = (end[0] + end[1])/2;
+                    end[2] -= avg;
+                    end[3] -= avg;
+                    end -=2;
                 }
-
-                string buf;
-                int len = huffmans_encode(buf, (uint16_t*)med.data(), med.size());
-                com += buf.size();*/
-            }
+            }*/
 
             // do not try to compress less than 32bytes
@@ -234 +225 @@
         {
             const double elep = Time().UnixTime()-start.UnixTime();
-            cout << "\r" << setprecision(0) << setw(3) << 100*proc << "% [" << setw(3) << 100.*com/tot << "%] cpu:" << setprecision(1) << sec << "s in:" << tot/1000000/elep << "MB/s" << flush;
+            cout << "\r" << setprecision(0) << setw(3) << 100*proc << "% [" << setprecision(1) << setw(5) << 100.*com/tot << "%] cpu:" << sec << "s in:" << tot/1000000/elep << "MB/s" << flush;
             frac += 0.01;
         }
@@ -240 +231 @@
 
     const double elep = Time().UnixTime()-start.UnixTime();
-    cout << setprecision(0) << "\r100% [" << setw(3) << 100.*com/tot << "%] cpu:" << setprecision(1) << sec << "s in:" << tot/1000000/elep << "MB/s" << endl;
+    cout << setprecision(0) << "\r100% [" << setprecision(1) << setw(5) << 100.*com/tot << "%] cpu:"  << sec << "s in:" << tot/1000000/elep << "MB/s" << endl;
 
     return 0;
@@ -393 +384 @@
         {
             const double elep = Time().UnixTime()-start.UnixTime();
-            cout << "\r" << setprecision(0) << setw(3) << 100*proc << "% [" << setw(3) << 100.*com/tot << "%] cpu:" << setprecision(1) << sec << "s out:" << tot/1000000/elep << "MB/s" << flush;
+            cout << "\r" << setprecision(0) << setw(3) << 100*proc << "% [" << setprecision(1) << setw(5) << 100.*com/tot << "%] cpu:" << sec << "s out:" << tot/1000000/elep << "MB/s" << flush;
             frac += 0.01;
         }
@@ -399 +390 @@
 
     const double elep = Time().UnixTime()-start.UnixTime();
-    cout << setprecision(0) << "\r100% [" << setw(3) << 100.*com/tot << "%] cpu:" << setprecision(1) << sec << "s out:" << tot/1000000/elep << "MB/s" << endl;
+    cout << setprecision(0) << "\r100% [" << setprecision(1) << setw(5) << 100.*com/tot << "%] cpu:" << sec << "s out:" << tot/1000000/elep << "MB/s" << endl;
 
     return 0;