The Table tab (shown in Figure 1) provides a textual representation of your data. In the simplest case where you open an instance of the Charting Tool with a single time series, the Table tab will contain two columns, one with time-stamps and the other with observations corresponding with that time-stamp. The date format is taken from your computer's system settings, which can be changed using the System settings.

If you assemble two or more graphs in the Chart tab, the Table tab will contain additional columns, one per graph, with the observations aligned with respect to time.

You can use the Search functionality to view data that falls within a range, for example. The field accepts boolean characters as well.

Figure 1. Charting Tool (Table tab)

Table Query Language

Introduction

Language Structure

There are two main search types:

1. String - these searches attempt to find the entered substring in any table cell.  No logical expressions can apply to these searches as they have no contextual information.
2. Expression - these searches determine the actual value of the cell in the appropriate format and allow for logical relationships

Which are based around four main types of cell information

1. Dates (Expression) - e.g., "01/07/2001"
2. Numerics (Expression) - e.g., "155.51"
3. Column Specifications (Expression) - e.g., "$1"
4. Arbitrary Strings (String) - e.g.,  "12/1", "12."

When a search is entered into the table, the parser will attempt to always match an Expression search.  In cases where this fails it will revert back to a String search.  Both String and Expression searches can be combined but no equality can be used to qualify the String portion

For example, if the user entered  "12/1" it would be a String search as there is not enough text entered to form a full date. This would result in it scanning through all cells and matching any in the Date column which contain the exact substring.   Entries such as: "12/10/2005" and "05/12/1001" would be highlighted.  However, if a full valid date is entered such as "12/10/2005" then this would be an Expression search and only the "12/10/2005" would be matched.  The downside of String searches is that they no not allow for any logic expressions as there is no context to the match.  So the user can't look for later dates based on the "> 12/1" String search, where-as the Expression search "> 12/10/2005" will.

Column Notation

Date Format

TQL can use dates as a value for evaluation.  It does this by converting the Date value into the machine's current Date culture.  This means that user should be aware of if they are using "dd/mm/yyyy" or "mm/dd/yyyy" format specifiers as part of their general operating system set-up.  Dates can only be used to compare and perform logical comparisons to other Dates within the first column ("$0")

TQL Examples

The following examples show typical usage, all date usages assume a culture format "dd/mm/yyyy".  For clarity, queries that are interpreted as a String search are indicated with an (S) while Expression searches are marked with an (E)

Appendix A - Language Definition

TQL is a context-free grammar which ignores white-space.  The Extended Backus-Naur Form metasyntax for TQL is as follows:

EBNF

   Statement := String | Expression, { Logical Expression };
  Expression := [Value] Logical Value;
       Value := Number | Date | Column;
      String := Digit | Point | Slash { Digit | Point | Slash };
     Logical := "&&" | "&" | "|" | "||";
    Equality := "<" | "<=" | ">" | ">=" | "!=" | "!" | "==" | "=";
      Column := "$", Natural;
        Date := Digit [, Digit], Slash, Digit [, Digit], Slash, Digit, Digit, Digit, Digit;
     Natural := Digit {Digit};
     Integer := ["-"], Natural;
       Point := ".";
       Slash := "/";
       Digit := "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9";
      Number := Integer, [Point, Digit {Digit}];