The Histories Section

<< Click to Display Table of Contents >>

Navigation:  Problem Descriptor Reference > The Sections of a Descriptor >

The Histories Section

Previous pageReturn to chapter overviewNext page

The HISTORIES section, which is optional, specifies values for which a time history is desired.  While multiple HISTORY statements can be listed they must all be of the form:

HISTORY ( arg1 [ ,arg2,...]  )

HISTORY ( arg1 [ ,arg2,...]  )  AT  (X1,Y1) [ (X2,Y2)...]


The coordinates specify locations in the problem at which the history is to be recorded.  If no coordinate is given, the arg must evaluate to a scalar.


The modifiers and reports available to PLOTS and MONITORS may also be applied to HISTORY statements.

The display of HISTORIES is controlled by the AUTOHIST select switch, which defaults to ON.  With the default setting all HISTORIES are automatically refreshed and displayed with the update of any MONITORS or PLOTS.

If desired, HISTORY statements can be included directly in the MONITORS section or PLOTS section.

Histories in Staged Problems

HISTORY statements may be used in STAGED problems as well as in time-dependent problems.  

In this case, the default abscissa will be stage number.  You can select a different value for the abscissa quantity by appending the clause


VERSUS expression


In this case, the values of the given expression in the various stages will be used as the plot axis.


Windowing History Plots


HISTORY plots by default display the total time range of the problem run.  Specific time ranges can be specified in several ways. A global window specifier can be set in the SELECT section:




This command causes all histories to display only the most recent time interval of the data.


Individual HISTORY plots can be windowed by the two plot qualifier forms:


WINDOW = time

selects a moving window containing the most recent time interval

WINDOW ( time1 , time2 )

selects a fixed time range, plotting the time between time1 and time2


See the sample problem "Samples | Usage | Two_Histories.pde" for an example.