2.2.3.2 Chart Data Cache

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A chart data cache is a local copy of the data for a chart (section 2.2.3.3). The chart data cache is used if data is missing or if links to external data sources are broken.

A chart data cache is specified by a sequence of records that conforms to the SERIESDATA rule (section 2.1.7.20.1) specified by the chart sheet substream (section 2.1.7.20.1) ABNF.

The following records and rules specify the significant parts of a chart data cache:

  • The Dimensions record (section 2.4.90) specifies the cells that contain data used by this chart.

  • The SIIndex record (section 2.4.262) specifies the beginning of a sequence of records that contains a cache of the data for the sequence of records that conforms to a specific AI rule (section 2.1.7.20.1) in the series (section 2.2.3.9) and error bars (section 2.2.3.13). The relationship between the series and the chart data cache is specified as follows:

  • The first SIIndex record in the chart sheet substream, which MUST contain a numIndex field equal to 0x0001, corresponds to the second sequence of records that conforms to the AI rule.

  • The second SIIndex record in the chart sheet substream, which MUST contain a numIndex field equal to 0x0002, corresponds to the third sequence of records that conforms to the AI rule.

  • The third SIIndex record in the chart sheet substream, which MUST contain a numIndex field equal to 0x0003, corresponds to the fourth sequence of records that conforms to the AI rule.

  • The Number (section 2.4.180), BoolErr (section 2.4.24), Blank (section 2.4.20), and Label (section 2.4.148) records each specify an individual value stored in the cache. Each column in the cache corresponds to a series or error bar, where the zero-based index of the column, specified by the cell.col field in the Number, BoolErr, Blank, or Label records, equals the zero-based index of the Series record (section 2.4.252) in the collection of Series records that corresponds to the series or error bar.

The following restrictions apply to the chart data cache:

  • The chart data cache MUST contain data that corresponds to a sequence of records that conforms to the AI rule in a series if the corresponding data is not specified in the chart or on the same sheet (1) as the chart.

  • The chart data cache MUST NOT contain data that corresponds to a sequence of records that conforms to the AI rule in a series if the corresponding data is specified in the chart or on the same sheet (1) as the chart.

  • The chart data cache MUST NOT contain data that corresponds to the third or fourth sequence of records that conforms to the AI rule in an error bar.

  • If the ebsrc field of the SerAuxErrBar record (section 2.4.249) in an error bar equals 0x04, the chart data cache MUST contain data that corresponds to the second sequence of records that conforms to the AI rule in the error bar.

  • If the ebsrc field of the SerAuxErrBar record in an error bar does not equal 0x04, the chart data cache MUST NOT contain data that corresponds to the second sequence of records that conforms to the AI rule in the error bar.

  • The chart data cache MUST NOT contain data that corresponds to a trendline (section 2.2.3.12).