Displaying a folded light curve

A folded light curve within a file can be displayed using the qcl procedure pl_fold.qcl. The following example displays the results from the program foldts, which folds the light curve on a range of periods. The procedure pl_fold.qcl displays, in this case, both the light curve folded at the best-fit period and the chi-square versus period tested. To ignore either plot, type "skip" at the prompt.

qcl>.pl_fold
QCL_CL File containing folded data = mkn335_91a.fld =   
QCL_CL Plotting device = xw =
Starting /ginga1/das/xanadu/leicester/osf/bin/pgxwin_server.
    Graphics device /xw open
QCL_CL Title for maximum chi-square plot or SKIP for none =
mkn335_91a.fld =
    HDS_NODE mkn335_91a.fld
    GRP_XMODE            1
    GRP_XNAM1 FLD_BASEPHI
    GRP_XNAM2 FLD_PHI_INT
    GRP_YMODE            3
    GRP_YNAM1 FLD_MAX_ARRAY
    GRP_YNAM2 FLD_MAX_VAR
    LABX  X                                                           
    LABY  Y                                                           
    Number of data points           20
    Range of data points
    X  0.500000E-01 to   1.95000    
    Y -0.177203     to  0.605928    
QCL_CL Minimum for fold plot = -0.39592840000000 =
QCL_CL Maximum for fold plot = 0.90841640000000 =
    Mapping   0.0000000E+00   2.000000     -0.3959284      0.9084164
    Position   1.00000     -0.395928    
    Position   1.00000      0.908416    
QCL_CL Title for Chi-square versus period plot or SKIP =
mkn335_91a.fld =
    HDS_NODE mkn335_91a.fld
    GRP_XMODE            0
    GRP_XNAM1 FLD_PERIODS
    GRP_XNAM2 DUM1
    GRP_YMODE            0
    GRP_YNAM1 FLD_CHI_ARRAY
    GRP_YNAM2 DUM2
    LABX  X                                                           
    LABY  Y                                                           
    Number of data points           11
    Range of data points
    X   10000.0     to   20000.0    
    Y   7.16076     to   17.5701    
    Mapping    10000.00       20000.00      0.0000000E+00   19.32708
 
 Device still open!
qcl>

In the case of a light curve folded on a single period, the procedure pl_fold.qcl does not prompt for the chi-square versus period plot.