Clean up options and help for fit over multiparam (gwastro#4640)

* Clean up options and help for fit over multiparam

Older code that this is copied from had the option of reading fit smoothing parameter values from an input fit file, rather than from the template bank (or calculating on the fly).  This is no longer done so remove the (useless) option and references to it in help for other options

* Update pycbc_fit_sngls_over_multiparam

Few more fixes to options, in particular 'required' & defaults

bin/all_sky_search/pycbc_fit_sngls_over_multiparam

@@ -174,18 +174,14 @@ parser = argparse.ArgumentParser(usage="",
 
 pycbc.add_common_pycbc_options(parser)
 parser.add_argument("--version", action=pycbc.version.Version)
-parser.add_argument("--template-fit-file",
+parser.add_argument("--template-fit-file", required=True,
                     help="hdf5 file containing fit coefficients for each"
                          " individual template. Required")
-parser.add_argument("--bank-file", default=None,
-                    help="hdf file containing template parameters. Required "
-                         "unless reading param from template fit file")
+parser.add_argument("--bank-file", required=True,
+                    help="hdf file containing template parameters. Required")
 parser.add_argument("--output", required=True,
                     help="Location for output file containing smoothed fit "
-                         "coefficients.  Required")
-parser.add_argument("--use-template-fit-param", action="store_true",
-                    help="Use parameter values stored in the template fit "
-                         "file as template_param for smoothing.")
+                         "coefficients. Required")
 parser.add_argument("--fit-param", nargs='+',
                     help="Parameter(s) over which to regress the background "
                          "fit coefficients. Required. Either read from "
@@ -196,20 +192,19 @@ parser.add_argument("--fit-param", nargs='+',
                          "multiple parameters, provide them as a list.")
 parser.add_argument("--approximant", default="SEOBNRv4",
                     help="Approximant for template duration. Default SEOBNRv4")
-parser.add_argument("--f-lower", type=float, default=0.,
-                    help="Starting frequency for calculating template "
-                         "duration, if not reading from the template fit file")
+parser.add_argument("--f-lower", type=float,
+                    help="Start frequency for calculating template duration.")
 parser.add_argument("--min-duration", type=float, default=0.,
                     help="Fudge factor for templates with tiny or negative "
                          "values of template_duration: add to duration values"
                          " before fitting. Units seconds.")
 parser.add_argument("--log-param", nargs='+',
-                    help="Take the log of the fit param before smoothing.")
+                    help="Take the log of the fit param before smoothing. "
+                         "Must be a list corresponding to fit params.")
 parser.add_argument("--smoothing-width", type=float, nargs='+', required=True,
-                    help="Distance in the space of fit param values (or the "
-                         "logs of them) to smooth over. Required. "
-                         "This must be a list corresponding to the smoothing "
-                         "parameters.")
+                    help="Distance in the space of fit param values (or their"
+                         " logs) to smooth over. Required. Must be a list "
+                         "corresponding to fit params.")
 parser.add_argument("--smoothing-method", default="smooth_tophat",
                     choices = _smooth_dist_func.keys(),
                     help="Method used to smooth the fit parameters; "
@@ -220,15 +215,14 @@ parser.add_argument("--smoothing-method", default="smooth_tophat",
                          "the smoothing until 500 triggers are reached. "
                          "'distance_weighted' weights the closest templates "
                          "with a normal distribution of width smoothing-width "
-                         "trucated at three smoothing-widths.")
+                         "truncated at three smoothing-widths.")
 parser.add_argument("--smoothing-keywords", nargs='*',
                     help="Keywords for the smoothing function, supplied "
                          "as key:value pairs, e.g. total_trigs:500 to define "
-                         "the number of templates in the n_closest smoothing "
-                         "method")
+                         "the number of templates for n_closest smoothing.")
 parser.add_argument("--output-fits-by-template", action='store_true',
                     help="If given, will output the input file fits to "
-                         "fit_by_template group")
+                         "fit_by_template group.")
 args = parser.parse_args()
 
 if args.smoothing_keywords: