removed builtins import

(was not working on my python2)
added plt.save_dst()
fixed pack function in dst.save() for python3

ess/TraceWin.py

@@ -14,13 +14,22 @@ class dst:
       - phi [rad]
       - E [MeV] (kinetic energy)
     '''
-    def __init__(self, filename):
+    def __init__(self, filename=None):
         # easy storage..
         self.filename=filename
         # used to create dict behaviour..
         self._columns=['x','xp','y','yp','phi','E']
-        # read in the file..
-        self._readBinaryFile()
+        if filename:
+            # read in the file..
+            self._readBinaryFile()
+        else:
+            import numpy
+            self.Np=0
+            self.Ib=0.0
+            self.freq=352.21
+            self._data=numpy.zeros((self.Np,6))
+            self.mass=0.0
+
 
     def append(self,x=0.0,xp=0.0,y=0.0,yp=0.0,E=0.0,phi=0.0):
         '''
@@ -51,7 +60,7 @@ class dst:
             self.Np-=1
 
     def _readBinaryFile(self):
-        # Thanks Emma!
+        # Thanks Ema!
 
         import numpy
 
@@ -119,12 +128,12 @@ class dst:
         import numpy
 
         fout=open(filename,'w')
-        out =pack('b',125)
-        out+=pack('b',100)
-        out+=pack('i',self.Np)
-        out+=pack('d',self.Ib)
-        out+=pack('d',self.freq)
-        out+=pack('b',125)
+        print(pack('b',125),end="",file=fout)
+        print(pack('b',100),end="",file=fout)
+        print(pack('i',self.Np),end="",file=fout)
+        print(pack('d',self.Ib),end="",file=fout)
+        print(pack('d',self.freq),end="",file=fout)
+        print(pack('b',125),end="",file=fout)
 
         data=self._data.copy()
 
@@ -143,10 +152,9 @@ class dst:
             data=data.reshape(self.Np*6,1)
 
         for x in data:
-            out+=pack('d',x)
+            print(pack('d',x),end="",file=fout)
 
-        out+=pack('d',self.mass)
-        print >>fout, out
+        print(pack('d',self.mass),end="",file=fout)
         fout.close()
 
     def subplot(self, index, x, y=None, nb=100, mask=None):
@@ -261,7 +269,6 @@ class plt:
         # Thanks Emma!
 
         import numpy
-        from builtins import range
 
         fin=open(self.filename,'r')
 
@@ -297,7 +304,7 @@ class plt:
         while i<self.Ne:
             SubHeader=numpy.fromfile(fin, dtype=SubHeader_type, count=1)
             # unfinished files need this fix (simulation still running)
-            if not SubHeader['Nelp']:
+            if len(SubHeader['Nelp'])==0:
                 break
             i=SubHeader['Nelp'][0]
 
@@ -374,7 +381,6 @@ class plt:
         (NOT necessarily reference)
         '''
         import numpy
-        from builtins import range
 
         if not hasattr(self,'avg'):
             self.calc_avg()
@@ -426,7 +432,6 @@ class plt:
         '''
 
         import numpy
-        from builtins import range
 
         if not hasattr(self,'avg'):
                self.calc_avg()
@@ -449,7 +454,6 @@ class plt:
         '''
 
         import numpy
-        from builtins import range
 
         if not hasattr(self,'sigma'):
                self.calc_sigma()
@@ -469,7 +473,6 @@ class plt:
         '''
 
         import numpy
-        from builtins import range
 
         if not hasattr(self,'sigma'):
                self.calc_sigma()
@@ -497,6 +500,25 @@ class plt:
         self.twiss_alpha = numpy.array(self.twiss_alpha)
 
 
+    def save_dst(self, index,filename=''):
+        import numpy
+   
+        dset=self[index]
+
+        _dst=dst()
+        _dst.freq=self.freq
+        _dst.Ib=self.Ib
+        _dst.Np=len(dset['x'])
+        _dst._data=numpy.array([dset['x'],
+                           dset['xp'],
+                           dset['y'],
+                           dset['yp'],
+                           dset['phi'],
+                           dset['E']]).transpose()
+        if filename:
+            _dst.save(filename)
+        return _dst
+
 
 
 class density_file:
@@ -651,7 +673,6 @@ class density_file:
     def _getFullContent(self):
 
         import numpy
-        from builtins import range
 
         #self._getHeader()
         # no need to read the header again:
@@ -962,7 +983,6 @@ class remote_data_merger:
         '''
 
         import numpy as np
-        from builtins import range
 
         h1=[]
         h2=[]
@@ -1018,8 +1038,6 @@ class partran(dict):
     '''
     Read partran1.out files..
     '''
-    # python 3 forward compatibility:
-    from builtins import range
 
     def __init__(self,filename):
         self.filename=filename