saxTransform: saxTransform

In Ghost: Missing Data Segments Imputation in Multivariate Streams

Description

This function is added to the package to enable users converting numeric data to discrete data. This is due to the fact that Ghost designed for discrete data and this function discretize numeric data and prepare them for the ghost algorithm.

Usage

saxTransform(data_frame, buckets,skipColumnVec,constraint_row)

Arguments

data_frame	A data frame with numeric values.
buckets	The Input data range is divided to this number.
skipColumnVec	Column number that is not used in the algorithm.
constraint_row	Column number that is considered for constant column.

Author(s)

Siyavash Shabani, [e-mail], Reza Rawassizadeh, [e-mail]

References

1- Rawassizadeh, Reza, Hamidreza Keshavarz, and Michael Pazzani. "Ghost Imputation: Accurately Reconstructing Missing Data of the Off Period." IEEE Transactions on Knowledge and Data Engineering (to appear).

2- Lin, J., Keogh, E., Lonardi, S., & Chiu, B. (2003). A symbolic representation of time series, with implications for streaming algorithms. In Proceedings of the 8th ACM SIGMOD workshop on Research issues in data mining and knowledge discovery (pp. 2-11). ACM.

Examples

data(sax_test)

#### Input dataframe-----------------------
#   S0  S1  S2 S3
#1   1   2  54 65
#2   1  NA  21 54
#3   2  34  32 87
#4   1  23  58 52
#5   1  43  75 56
#6   2  12  20 95
#7   1  54  14 87
#8   3  -6  NA 30
#9   2   5 -60 32
#10  1 -85  58 25
#11  2  78  95 45
#12  3  52  52 62
#13  2  20  NA 58
#14  3  NA -62 78
#15  1  20 -10 96
#16  1  30  -6 NA
#17  1  12 -85 45
#18  1  NA  78 20
#19  1  23  95 NA

saxTransform(sax_test,buckets =10,skipColumnVec=1, constraint_row=1)

### Output data----------------------------------------------
#     S0  S1  S2   S3
# [1,] "1" "2" "54" "65"
# [2,] "1" ""  "f"  "h"
# [3,] "2" "g" "g"  "j"
# [4,] "1" "g" "h"  "h"
# [5,] "1" "h" "i"  "h"
# [6,] "2" "f" "f"  "k"
# [7,] "1" "h" "f"  "j"
# [8,] "3" "e" ""   "g"
# [9,] "2" "f" "b"  "g"
#[10,] "1" "a" "h"  "g"
#[11,] "2" "j" "k"  "h"
#[12,] "3" "h" "h"  "i"
#[13,] "2" "f" ""   "h"
#[14,] "3" ""  "b"  "j"
#[15,] "1" "f" "e"  "k"
#[16,] "1" "g" "e"  ""
#[17,] "1" "f" "a"  "h"
#[18,] "1" ""  "j"  "f"
#[19,] "1" "g" "k"  ""

Ghost documentation built on March 26, 2020, 6:45 p.m.