Description

proc usedata may be used to select the "current data set" for plotting when more than one data set resides in memory. Additional in-memory data sets can be generated, for instance, by proc tabulate or proc processdata.

Ploticus accomodates multiple in-memory data sets using a stack mechanism. Stack elements are identified by number. When a data set is read using proc getdata the resulting data becomes element 0. If proc tabulate or proc processdata are invoked to derive data, the result becomes element 1. If another proc tabulate or proc processdata is applied to element 1, the result becomes element 2. And so on.

Normally the current data set for plotting is always the result of the most recent getdata, processdata, or tabulate. proc usedata is used on those occasions where it is necessary to get back to the original data set, or access a data set that is lower on the stack.

Notes

The old proc originaldata now maps to this proc, equivalent to original: yes.

Attributes

If no attributes are specified, the default action is original: yes

original yes

The data most recently read by proc getdata becomes the current data set for plotting.

element n

Element n becomes the current data set for plotting.

pop n

n elements are popped from the stack to arrive at the current data set for plotting.

Example

   #proc usedata
     original: yes