function?x?=?f_alpha_tgaussian?（?n?q_d?r?alpha?）

%*****************************************************************************80
%
%%?F_ALPHA_TGAUSSIAN?generates?noise?using?a?truncated?Gaussian?distribuion.
%
%??Discussion:
%
%????This?function?generates?a?discrete?colored?noise?vector?X?of?size?N
%????with?a?power?spectrum?distribution?that?behaves?like?1?/?f^ALPHA.
%????The?white?noise?used?in?the?generation?is?sampled?from?a?truncated
%????Gaussian?distribution?with?zero?mean?variance?Q_D?and?
%????a?range?of?（-RANGE+RANGE）.
%
%??Licensing:
%
%????This?code?is?distributed?under?the?GNU?LGPL?license.
%
%??Modified:
%
%????30?March?2011
%
%??Author:
%
%????Miroslav?Stoyanov
%
%??Reference:
%
%????Jeremy?Kasdin
%????Discrete?Simulation?of?Colored?Noise?and?Stochastic?Processes
%????and?1/f^a?Power?Law?Noise?Generation
%????Proceedings?of?the?IEEE
%????Volume?83?Number?5?1995?pages?802-827.
%????
%????Miroslav?Stoyanov?Max?Gunzburger?John?Burkardt
%????Pink?Noise?1/F^Alpha?Noise?and?Their?Effect?on?Solution
%????of?Differential?Equations
%????submitted?International?Journal?for?Uncertainty?Quantification.
%
%??Parameters:
%
%????Input?integer?N?the?number?of?elements?in?the?discrete?noise?vector.
%
%????Input?real?Q_D?the?variance?of?the?Gaussian?distribution.??A?standard
%????Gaussian?distribution?has?a?variance?of?1.??The?variance?is?the?square
%????of?the?standard?deviation.
%
%????Input?real?R?the?upper?va