clipping routines

field.py

@@ -214,6 +214,35 @@ class Field3d:
         data = self.data[sl]
         return Field3d(data,origin,spacing,deep=deep)
 
+    def clip(self,position,axis,invert=False,deep=False):
+        idx_clip = self.nearest_gridpoint(coord,axis=axis,lower=True)
+        sl = 3*[slice(None)]
+        origin_  = self.origin
+        spacing_ = self.spacing
+        if invert:
+            sl[axis] = slice(idx_clip+1,None)
+            origin_[axis] = self.origin[axis]+idx_clip*self.spacing[axis]
+        else:
+            sl[axis] = slice(0,idx_clip+1)
+        data_ = self.data[tuple(sl)]
+        return Field3d(data_,origin_,spacing_,deep=deep)
+
+    def clip_box(self,bounds,deep=False,is_relative=False):
+        if is_relative:
+            bounds = tuple(self.origin[ii//2] + bounds[ii]*self.dim(ii//2)*self.spacing[ii//2] for ii in range(6))
+            print(bounds)
+        idx_lo = self.nearest_gridpoint((bounds[0],bounds[2],bounds[4]),lower=True)
+        idx_hi = self.nearest_gridpoint((bounds[1],bounds[3],bounds[5]),lower=True)
+        origin_  = self.origin
+        spacing_ = self.spacing
+        idx_lo = tuple(0 if idx_lo[axis]<0 else idx_lo[axis] for axis in range(3))
+        idx_hi = tuple(0 if idx_hi[axis]<0 else idx_hi[axis] for axis in range(3))
+        sl_ = tuple([slice(idx_lo[0],idx_hi[0]+1),
+                     slice(idx_lo[1],idx_hi[1]+1),
+                     slice(idx_lo[2],idx_hi[2]+1)])
+        data_ = self.data[sl_]
+        return Field3d(data_,origin_,spacing_,deep=deep)
+
     def coordinate(self,idx,axis=None):
         if axis is None:
             assert len(idx)==3, "If 'axis' is None, 'idx' must be a tuple/list of length 3."