to_all_interval_formats: Convert Interval Data to All Supported Formats

In dataSDA: Datasets and Basic Statistics for Symbolic Data Analysis

Convert Interval Data to All Supported Formats

Description

Convert interval data from any recognized format to all six supported interval data formats and return the results as a named list. This is useful for inspecting and comparing how the same interval data is represented across different formats.

Usage

to_all_interval_formats(x, ...)

Arguments

x	Interval data in one of the supported formats: "RSDA", "MM", "iGAP", "ARRAY", "SODAS", or "SDS".
...	Additional arguments passed to conversion functions (e.g., location for iGAP input).

Details

Six interval data formats are supported in this package. Each format stores the same information – lower and upper bounds for every variable of every observation – but differs in its structure and origin:

RSDA

A symbolic_tbl object (class c("symbolic_tbl", "tbl_df", "tbl", "data.frame")) where each interval variable is a complex column (symbolic_interval): Re() gives the minimum and Im() gives the maximum. This is the native format of the RSDA package (Billard & Diday, 2006; Rodriguez, 2024).

MM (Min-Max)

A plain data.frame where each interval variable is represented by two numeric columns named <var>_min and <var>_max. This is a widely used general-purpose representation.

iGAP

A data.frame where each interval variable is stored as a character column with comma-separated values "min,max". This is the format used by the iGAP software (Correia, 2009).

ARRAY

A three-dimensional numeric array of size [n, p, 2]. The first slice [,,1] contains all minima and the second slice [,,2] contains all maxima. Dimnames encode observation labels, variable names, and c("min", "max"). This format is convenient for matrix-based computations.

SODAS

An XML file on disk produced by the SODAS software (Diday & Noirhomme, 2008). In R, SODAS data is referenced by its file path and read via RSDA::SODAS.to.RSDA(). Since SODAS is a file-based format, it cannot be generated from in-memory data.

SDS

An alias for SODAS. Both refer to the same XML-based format.

Value

A named list with six slots:

RSDA

A symbolic_tbl with complex-encoded symbolic_interval columns.

MM

A data.frame with paired _min/_max columns.

iGAP

A data.frame with comma-separated "min,max" character values.

ARRAY

A three-dimensional numeric array of dimension [n, p, 2] where [,,1] stores minima and [,,2] stores maxima.

SODAS

NULL unless the input is a SODAS XML file path, in which case it stores the original path.

SDS

NULL unless the input is a SODAS/SDS XML file path (alias for SODAS).

Author(s)

Han-Ming Wu

References

Billard, L. and Diday, E. (2006). Symbolic Data Analysis: Conceptual Statistics and Data Mining. Wiley.

Rodriguez, O. (2024). RSDA: R to Symbolic Data Analysis. R package, https://CRAN.R-project.org/package=RSDA.

Correia, M. (2009). Interval GARCH and Aggregation of Predictions.

Diday, E. and Noirhomme-Fraiture, M. (2008). Symbolic Data Analysis and the SODAS Software. Wiley.

See Also

int_detect_format, int_convert_format, int_list_conversions

Examples

data(car.int)
result <- to_all_interval_formats(car.int)
names(result)

# RSDA format (symbolic_tbl)
result$RSDA

# MM format (data.frame with _min/_max columns)
head(result$MM)

# iGAP format (data.frame with comma-separated values)
head(result$iGAP)

# ARRAY format (3D array)
dim(result$ARRAY)
result$ARRAY[1:3, , 1]  # minima
result$ARRAY[1:3, , 2]  # maxima

# SODAS/SDS slots are NULL (file-based format)
result$SODAS
result$SDS

dataSDA documentation built on June 12, 2026, 9:06 a.m.