Adds max_fraction_memory to change the fraction of memory used for multiprocessing

DSSC.py

@@ -43,6 +43,7 @@ class DSSC:
         self.aspect = self.px_pitch_v/self.px_pitch_h # aspect ratio of the DSSC images
         self.geom = None
         self.mask = None
+        self.max_fraction_memory = 0.8
         
         print('DSSC configuration')
         print(f'Topic: {self.topic}')
@@ -288,7 +289,7 @@ class DSSC:
         print(f'max available memory: {max_GB} GB')
         
         # max_GB / (8byte * 16modules * 128px * 512px * N_pulses)
-        self.chunksize = int(0.8*max_GB * 1024**3 // (8 * 16 * 128 * 512 * self.fpt))
+        self.chunksize = int(self.max_fraction_memory*max_GB * 1024**3 // (8 * 16 * 128 * 512 * self.fpt))
         
         print('processing', self.chunksize, 'trains per chunk')