ReadElems

file,-folder-and-read-functions ReadElems

syntax

  • ReadElems(sourceLines, valuesunit, startpositions, flagsvalue)

definition

ReadElems(sourceLines, valuesunit, startpositions, flagsValue) results in an attribute, with column(s) of values of the sourceLines argument, for the domain-unit of the first and third argument.

The resulting data-item contains the values of the sourceLines argument, starting at the startpositions that need to be configured for each element of the domain unit.

Spaces, tabs, comma’s(if comma is not configured as decimal separator) and semicolons are used as field delimiters.

This function also generates an uint32 attribute for the same domain unit, called readPos, containing the read positions after parsing a value from each line.

The position is after reading the delimiter that ended the scanning of the read element, so this can be directly used to read the next field form a set of lines.

applies to

  • attribute sourceLines with string value-type
  • valuesunit is the unit that is attributed to the resulting values and their value type. This type determines how characters are scanned, ie. integer are read until a non integer character is scanned, floating points can contain a decimal separator (default is the period) and can be in scientific notation (i.e. 1.23e+4). Strings can be quoted and quotes (single or double) will be removed during reading.
  • startpositions is a an attribute with uint32 value type
  • flagsValue is an optional uint32 parameter that indicates reading flags, which can be an additive combination of any of the following values:
    • 1: commaAsDecimalSeparator: indicates a comma is interpreted as decimal separator, without this flag, the point is assumed to be the decimal-separator.
    • 2: noNegatives: indicates that a hyphen will be interpreted as a separate single character punctuation token and not as the start of a numeric value (starting from 7.411)
    • 4: noScientific: indicates that scientific number representation (with ‘e’) is not an option when reading a number (starting from version 7.411)
    • 8: noTabAsValueSeparator (starting from version 7.411)
    • 16: noSpaceAsStringTerminator (starting from version 7.411)

conditions

  • The domain unit of the sourceLines and startpositions arguments must match.

example 

container ReadElems
{
   parameter<string> file: StorageName = "%projDir%/data/text.txt",  StorageType = "str";

   unit<uint32>       BDomain: nrofrows = 6;
   parameter<float32> Body:= ReadLines(File, BDomain, 0);

   attribute<uint32> FirstColumn (ReadLine/BDomain) := ReadElems(Body, uint32, const(0, BDomain));
   attribute<uint32> LastColumn  (ReadLine/BDomain) := ReadElems(Body, uint32, FirstColumn/readPos);
};
             
25000 27500 11000 6100 14400 300 70
30000 32500 12000 6200 14500 320 72
35000 37500 13000 6300 14600 340 74
40000 42500 14000 6400 14700 360 76
45000 47500 15000 6500 14800 380 78
50000 52500 16000 6600 14900 400 80

text.txt

FirstColumn LastColumn
25000 70
30000 72
35000 74
40000 76
45000 78
50000 80

BDomain, nr of rows = 6

see also