Differences between revisions 1 and 7 (spanning 6 versions)

Iterating through the pixels in the EMData object

In your Python script you can use commands like this to iterate through the pixels in an EMData object

   1 a = test_image()
   2 for k in xrange(a["nz"]):
   3     for j in xrange(a["ny"]):
   4         for i in xrange(a["nx"]):
   5             pixel_value = a[i,j,k] # get the pixel value
   6             a[i,j,k]=pixel_value*3 # set the pixel value

Note that you can do any of:

   1 a[x]
   2 a[x,y]
   3 a[x,y,z]
   4 a[attr_name]

The fourth form allows getting and setting attributes equivalent to set_attr() and get_attr().

-  ⇤ ← Revision 1 as of 2009-03-23 19:36:04 → 
  Size: 44
  Editor: DavidWoolford
  Comment:
+   ← Revision 7 as of 2015-08-14 22:11:14 → ⇥
  Size: 596
  Editor: SteveLudtke
  Comment:
-Deletions are marked like this.
+Additions are marked like this.
 Line 1:
-Describe EMAN2/Tutorials/iter_pixels here.
+= Iterating through the pixels in the EMData object =

In your Python script you can use commands like this to iterate through the pixels in an EMData object

{{{#!python
a = test_image()
for k in xrange(a["nz"]):
    for j in xrange(a["ny"]):
        for i in xrange(a["nx"]):
            pixel_value = a[i,j,k] # get the pixel value
            a[i,j,k]=pixel_value*3 # set the pixel value
}}}

Note that you can do any of:

{{{#!python
a[x]
a[x,y]
a[x,y,z]
a[attr_name]
}}}

The fourth form allows getting and setting attributes equivalent to set_attr() and get_attr().