document negative indexing

Author: lewardo

doc/DataSeries.rst

@@ -33,7 +33,7 @@
 
    :arg buffer: A |buffer| to write the frame to (only the first channel is used, will be resized).
 
-   Get a frame from a series. If the identifier doesn't exist or if that series doesnt have a frame for that time point an error will be reported.
+   Get a frame from a series. Negative indexing starts from the last frame. If the identifier doesn't exist or if that series doesnt have a frame for that time point an error will be reported.
 
 :message getSeries:
 
@@ -51,7 +51,7 @@
 
    :arg buffer: A |buffer| containing the data for the frame (only the first channel is used).
 
-   Updates a time frame in a series, or adds it to the end if there is no frame at that time point. Sets the dimensionality of the DataSeries if it is the first frame added, otherwise if the buffer is too short an error will be reported.
+   Updates a time frame in a series, or adds it to the end if there is no frame at that time point. Negative indexing starts from the last frame. Sets the dimensionality of the DataSeries if it is the first frame added, otherwise if the buffer is too short an error will be reported.
 
 :message setSeries:
 
@@ -69,7 +69,7 @@
 
    :arg buffer: A |buffer| containing the data for the frame (only the first channel is used).
 
-   Updates an existing frame. If the buffer is too short an error will be reported. If the identifier doesn't exist or if that series doesnt have a frame for that time point an error will be reported.
+   Updates an existing frame. Negative indexing starts from the last frame. If the buffer is too short an error will be reported. If the identifier doesn't exist or if that series doesnt have a frame for that time point an error will be reported.
 
 :message updateSeries:
 
@@ -85,7 +85,7 @@
 
    :arg time: which time frame to remove.
 
-   Delete a frame from a series, deletes the series if it is the only frame. If the identifier doesn't exist or if that series doesnt have a frame for that time point an error will be reported.
+   Delete a frame from a series, deletes the series if it is the only frame. Negative indexing starts from the last frame. If the identifier doesn't exist or if that series doesnt have a frame for that time point an error will be reported.
 
 :message deleteSeries:
 
@@ -99,7 +99,7 @@
 
    :arg dataSet: The Dataset to write the slice to. Will overwrite and resize.
 
-   Get a dataset with the `time`th frame of every series, i.e. can create a :fluid-obj:`DataSet` with every Nth frame of every series. If an identifier doesn't have enough frames it is merely not added to the output dataset.
+   Get a dataset with the `time`th frame of every series, i.e. can create a :fluid-obj:`DataSet` with every Nth frame of every series. Negative indexing starts from the last frame. If an identifier doesn't have enough frames it is merely not added to the output dataset.
 
 :message clear: