Lists and ranges

Some applications require the user to specify various ranges, BINSUBSET is an obvious example; EVBIN when irregularly binning an axis is another.

Responses to these prompts should be made in the standard ASTERIX way, described here.

Basically, the user types in the lower and upper bounds for each range required. There are, however, special characters and syntax rules to bear in mind.

• Delimiters. There are 3 basic delimiters:
  1. Between the lower and upper bounds of a given range, this is represented by a colon ':' e.g. 10:20 i.e. lower bound = 10, upper bound = 20
  2. Between two separate ranges, this is represented by either a semi-colon ';' or by a space ' ' e.g. 10:20 20:30 or 10:20;20:30
  3. Between ranges for different dimensions, this is represented by a comma ',' (Not many applications use this facility.) e.g. 10:20 20:30,5:6 11:12
• Special Characters There are 2 further characters which have special meaning:
  1. The asterisk '*' may be used to specify the extreme values. Thus if it is used as a lower bound it represents the minimum value of the range, whereas if used as the upper bound it represents the maximum value of the range. e.g. If the maximum value is 1000 and the minimum value is 0, then: *:200 300:400 500:* is equivalent to 0:200;300:400;500:1000 and to 0:200 300:400 500:1000
  2. The ampersand '&' may be used to specify that the input will continue. Place it at the end of a line of input and type the return key. You will be prompted to continue your input. e.g.

            Enter ranges > 10:20 30:40 & <RETURN>
            Continuation > 50:60 <RETURN>
     

     Is the same as:

            Enter Ranges > 10:20;30:40;50:60 <RETURN>
     

• Other features. There are three other features to help you:
  1. All extra spaces are ignored, eg.

             10 : 20   20 : 30; 30:40
     

     Is the same as:

             10:20;20:30;30:40
     

  2. Implicit lower bounds. If no lower bound is specified, then it will be assumed to be the same as the previous upper bound, eg.

             10:20:30:40:50 70:80
     

     Is the same as:

             10:20 20:30 30:40 40:50 70:80
     

  3. Implicit upper bounds. If no upper bound is specified, then it will be assumed to be the same as the lower bound. e.g. 10 20:30 40 Is the same as: 10:10 20:30 40:40

1. These range specifications are read in as a CHARACTER string. You should not, however, have to enclose them in single speech marks.
2. When binning lower bounds are inclusive, but upper bounds are exclusive, thus consecutive ranges are OK. The use of implicit upper bounds would, however, have no meaning in this context!