##FastGaSP 0.6.4
* update the initial value for log(beta) in GPPCA estimation

##FastGaSP 0.6.3
* output the predict.fgasp function same as the predict function
* output input_sorted_ix as sorted index in fgasp
* allow users to output several indices relevant to sorting in predict.fgasp
* revise and output predict.fgasp

##FastGaSP 0.6.2
* Add kernel_type="matern_3_2" by including functions: Construct_W0_matern_3_2, Construct_G_matern_3_2, Construct_W_matern_3_2 and modify relevant functions

##FastGaSP 0.6.1
* Add the unnormalized_Vicsek function for simulation 
* Update the fit.particle.data and simulate_particle.Rd functions to integrate the unnormalized_Vicsek simulation
* Add the IKF function for computing inverse Kalman filter 

##FastGaSP 0.6.0
* Add functions related to the inverse Kalman filter (IKF) algorithm, IKF-CG, GPPCA and FMOU
* Update the reference in description

##FastGaSP 0.5.3
 * Fix the issues of the unused arguments ‘have_noise’ in Get_C_R_K_Q.Rd and  ‘C0’ in 'Sample_KF_post.Rd'
 * remove dependence of RobustGaSP
 * remove the issue of Rd file in show.fgasp function
 * update the reference in description

##FastGaSP 0.5.2
 * Update the references in the document	
 * Update the Email address of the maintainer 

## FastGaSP 0.5.1
 * Add a case where sigma_2 is fixed when performing the prediction
