Syntax:

$ ./vartools -i EXAMPLES/3.starspot -oneline \
    -aov Nbin 20 0.1 10. 0.1 0.01 5 0 \
    -Starspot aov 0.0298 0.08745 20. 85. 30. 0. -1 \
        1 0 0 1 1 1 1 1 0 1 EXAMPLES/OUTDIR1/

Name                   = EXAMPLES/3.starspot
Period_1_0             =     3.07960303
AOV_1_0                = 2861.35783
AOV_SNR_1_0            = 605.83431
AOV_NEG_LN_FAP_1_0     = 4755.85353
Period_2_0             =     3.08383230
AOV_2_0                = 2559.76138
AOV_SNR_2_0            = 541.88234
AOV_NEG_LN_FAP_2_0     = 4578.45788
Period_3_0             =     3.10356260
AOV_3_0                = 2165.11113
AOV_SNR_3_0            = 458.19878
AOV_NEG_LN_FAP_3_0     = 4314.25066
Period_4_0             =     6.36005672
AOV_4_0                = 1514.99364
AOV_SNR_4_0            = 320.34471
AOV_NEG_LN_FAP_4_0     = 3762.76328
Period_5_0             =     3.19393583
AOV_5_0                = 1026.91829
AOV_SNR_5_0            = 216.85084
AOV_NEG_LN_FAP_5_0     = 3185.86267
Starspot_Period_1      =     3.12218969
Starspot_a_1           =   0.02980
Starspot_b_1           =   0.08745
Starspot_alpha_1       =  22.51312
Starspot_inclination_1 =  69.03963
Starspot_chi_1         =  30.00411
Starspot_psi0_1        =   0.00000
Starspot_mconst_1      =  10.16641
Starspot_chi2perdof_1  =  26.58796

Find the rotation period of the simulated light curve EXAMPLES/3.starspot using the -aov command, and then fit a Dorren 1987 single-starspot model to the light curve. Take the period from the -aov command, take 0.0298 and 0.08745 for the parameters a and b, and set the initial values of the spot radius, stellar inclination, spot latitude, and spot longitude to 20., 85., 30., and 0. degrees, respectively. Have the routine automatically determine the initial value for the unspotted photosphere magnitude (by giving -1 for the initial value). We set the flags to vary the period, spot radius, inclination, latitude, longitude, and unspotted magnitude. We keep a and b fixed. We do not subtract the model from the light curve. We output the best-fit model to the directory EXAMPLES/OUTDIR1 (the filename will be 3.starspot.starspot.model). The light curve was simulated with parameters P = 3.12345, a=0.0298, b=0.08745, alpha=30., i=90., chi=45. Due to degeneracies in the model, the recovered values are substantially different from the input values.