Merge pull request #8 from alasdairwilson/startn-end-skip-docs

Added explanation of start, end, skip kwargs when loading directories

examples/io/loading_a_directory.py

@@ -10,5 +10,19 @@
 from ripplemapper.io import load_dir_to_obj
 
 imgs = load_dir_to_obj(example_dir)
+print(imgs)
+
+#################################################################
+#
+# We can also select a subset of the images in our path with start, end and skip kwargs.
+# These integer valued parameters work like python slicing [start:end:skip].
 
+imgs = load_dir_to_obj(example_dir, start=0, end=3, skip=2)
 print(imgs)
+
+#################################################################
+#
+# This allows you to chunk up your input into independent processes or to quickly load a subset of your data for testing.
+#
+# Since you can save and load RippleImage objects, you can also save the subset of images.
+# If this is done without the image arrays then you can fit far more images in memory at once