Blurb::
Samples variables along a user-defined vector

Description::
Dakota's vector parameter study computes response data sets at
selected intervals along a vector in parameter space. It is often used
for single-coordinate parameter studies (to study the effect of a
single variable on a response set), but it can be used more generally
for multiple coordinate vector studies (to investigate the response
variations along some n-dimensional vector such as an optimizer search
direction).

<b> Default Behavior </b>

By default, the vector parameter study operates over all
types of variables.

<b> Expected Outputs </b>

A vector parameter study produces a set of responses for
each parameter set that is generated.

<b> Expected HDF5 Output </b>

If Dakota was built with HDF5 support and run with the 
\ref environment-results_output-hdf5 keyword, this method
writes the following results to HDF5:

- \ref hdf5_results-pstudies

<b> Usage Tips </b>

<b> Group 1 </b> is used to define the vector along which the parameters are 
varied. Both cases also rely on the variables specification of an
initial value, through:
\li the \ref variables-continuous_design-initial_point keyword
\li the \ref variables-continuous_state-initial_state keyword 
\li relying on the default initial value, based on the rest of the
    variables specification

From the initial value, the vector can be defined using one of the
two keyword choices.

Once the vector is defined, the samples are then fully specifed
by \ref method-vector_parameter_study-num_steps.

Topics::	parameter_studies
Examples::

The following example is a good comparison to the examples on
\ref method-multidim_parameter_study and \ref method-centered_parameter_study.
\verbatim
# tested on Dakota 6.0 on 140501
environment
  tabular_data
    tabular_data_file = 'rosen_vector.dat'

method
  vector_parameter_study
    num_steps = 10
    final_point =    2.0      2.0
model
  single

variables
  continuous_design = 2
    initial_point =   -2.0     -2.0
    descriptors =     'x1'     "x2"

interface
  analysis_driver = 'rosenbrock'
    fork

responses
  response_functions = 1
  no_gradients
  no_hessians

\endverbatim

Theory::
Faq::
See_Also::	method-centered_parameter_study, method-multidim_parameter_study, method-list_parameter_study
