Table
¶
A two-dimensional collection of data. It can either be seen as a list of rows or as a list of columns.
To create a Table
call the constructor or use one of the following static methods:
- Table.fromCsvFile: Create a table from a CSV file.
- Table.fromJsonFile: Create a table from a JSON file.
- Table.fromParquetFile: Create a table from a Parquet file.
- Table.fromColumns: Create a table from a list of columns.
- Table.fromMap: Create a table from a map.
Parameters:
Name | Type | Description | Default |
---|---|---|---|
data |
Map<String, List<Any?>> |
The data of the table. If null, an empty table is created. | - |
Examples:
Stub code in Table.sdsstub
28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 |
|
columnCount
¶
The number of columns.
Note: This operation must compute the schema of the table, which can be expensive.
Type: Int
columnNames
¶
The names of the columns in the table.
Note: This operation must compute the schema of the table, which can be expensive.
Type: List<String>
plot
¶
The plotter for the table.
Call methods of the plotter to create various plots for the table.
Type: TablePlotter
rowCount
¶
The number of rows.
Note: This operation must fully load the data into memory, which can be expensive.
Type: Int
schema
¶
The schema of the table, which is a mapping from column names to their types.
Note: This operation must compute the schema of the table, which can be expensive.
Type: Schema
addColumns
¶
Add columns to the table and return the result as a new table.
Note: The original table is not modified.
Parameters:
Name | Type | Description | Default |
---|---|---|---|
columns |
union<Column<Any?>, List<Column<Any?>>, Table> |
The columns to add. | - |
Results:
Name | Type | Description |
---|---|---|
newTable |
Table |
The table with the additional columns. |
Examples:
pipeline example {
val table = Table({"a": [1, 2, 3]});
val newColumn = Column("b", [4, 5, 6]);
out table.addColumns(newColumn);
}
Stub code in Table.sdsstub
addComputedColumn
¶
Add a computed column to the table and return the result as a new table.
Note: The original table is not modified.
Parameters:
Name | Type | Description | Default |
---|---|---|---|
name |
String |
The name of the new column. | - |
computer |
(row: Row) -> (cell: Cell<Any?>) |
The function that computes the values of the new column. | - |
Results:
Name | Type | Description |
---|---|---|
newTable |
Table |
The table with the computed column. |
Examples:
pipeline example {
val table = Table({"a": [1, 2, 3], "b": [4, 5, 6]});
out table.addComputedColumn("c", (row) -> row["a"] + row["b"]);
}
Stub code in Table.sdsstub
addIndexColumn
¶
Add an index column to the table and return the result as a new table.
Note: The original table is not modified.
Parameters:
Name | Type | Description | Default |
---|---|---|---|
name |
String |
The name of the new column. | - |
firstIndex |
Int |
The index to assign to the first row. Must be greater or equal to 0. | 0 |
Results:
Name | Type | Description |
---|---|---|
newTable |
Table |
The table with the index column. |
Examples:
pipeline example {
val table = Table({"a": [1, 2, 3], "b": [4, 5, 6]});
out table.addIndexColumn("id");
out table.addIndexColumn("id", firstIndex = 10);
}
Stub code in Table.sdsstub
addTablesAsColumns
¶
Add the columns of other tables and return the result as a new table.
Note: The original tables are not modified.
Parameters:
Name | Type | Description | Default |
---|---|---|---|
others |
union<List<Table>, Table> |
The tables to add as columns. | - |
Results:
Name | Type | Description |
---|---|---|
newTable |
Table |
The table with the columns added. |
Examples:
pipeline example {
val table1 = Table({"a": [1, 2, 3]});
val table2 = Table({"b": [4, 5, 6]});
out table1.addTablesAsColumns(table2);
}
Stub code in Table.sdsstub
addTablesAsRows
¶
Add the rows of other tables and return the result as a new table.
Note: The original tables are not modified.
Parameters:
Name | Type | Description | Default |
---|---|---|---|
others |
union<List<Table>, Table> |
The tables to add as rows. | - |
Results:
Name | Type | Description |
---|---|---|
newTable |
Table |
The table with the rows added. |
Examples:
pipeline example {
val table1 = Table({"a": [1, 2, 3]});
val table2 = Table({"a": [4, 5, 6]});
out table1.addTablesAsRows(table2);
}
Stub code in Table.sdsstub
countRowsIf
¶
Count how many rows in the table satisfy the predicate.
The predicate can return one of three results:
- true, if the row satisfies the predicate.
- false, if the row does not satisfy the predicate.
- null, if the truthiness of the predicate is unknown, e.g. due to missing values.
By default, cases where the truthiness of the predicate is unknown are ignored and this method returns how often the predicate returns true.
You can instead enable Kleene logic by setting ignoreUnknown = false
. In this case, this method returns null if
the predicate returns null at least once. Otherwise, it still returns how often the predicate returns true.
Parameters:
Name | Type | Description | Default |
---|---|---|---|
predicate |
(row: Row) -> (satisfiesPredicate: Cell<Boolean?>) |
The predicate to apply to each row. | - |
ignoreUnknown |
Boolean |
Whether to ignore cases where the truthiness of the predicate is unknown. | true |
Results:
Name | Type | Description |
---|---|---|
count |
Int? |
The number of rows in the table that satisfy the predicate. |
Examples:
pipeline example {
val table = Table({"col1": [1, 2, 3], "col2": [1, 3, null]});
out table.countRowsIf((row) -> row["col1"] < row["col2"]);
out table.countRowsIf((row) -> row["col1"] < row["col2"], ignoreUnknown = false);
}
Stub code in Table.sdsstub
filterRows
¶
Keep only rows that satisfy a condition and return the result as a new table.
Note: The original table is not modified.
Parameters:
Name | Type | Description | Default |
---|---|---|---|
predicate |
(row: Row) -> (satisfiedPredicate: Cell<Boolean?>) |
The function that determines which rows to keep. | - |
Results:
Name | Type | Description |
---|---|---|
newTable |
Table |
The table containing only the specified rows. |
Examples:
pipeline example {
val table = Table({"a": [1, 2, 3], "b": [4, 5, 6]});
out table.filterRows((row) -> row["a"] == 2);
}
Stub code in Table.sdsstub
filterRowsByColumn
¶
Keep only rows that satisfy a condition on a specific column and return the result as a new table.
Note: The original table is not modified.
Parameters:
Name | Type | Description | Default |
---|---|---|---|
name |
String |
The name of the column. | - |
predicate |
(cell: Cell<Any?>) -> (satisfiesPredicate: Cell<Boolean?>) |
The function that determines which rows to keep. | - |
Results:
Name | Type | Description |
---|---|---|
newTable |
Table |
The table containing only the specified rows. |
Examples:
pipeline example {
val table = Table({"a": [1, 2, 3], "b": [4, 5, 6]});
out table.filterRowsByColumn("a", (cell) -> cell == 2);
}
Stub code in Table.sdsstub
getColumn
¶
Get a column from the table.
Parameters:
Name | Type | Description | Default |
---|---|---|---|
name |
String |
The name of the column. | - |
Results:
Name | Type | Description |
---|---|---|
column |
Column<Any> |
The column. |
Examples:
Stub code in Table.sdsstub
getColumnType
¶
Get the type of a column.
Parameters:
Name | Type | Description | Default |
---|---|---|---|
name |
String |
The name of the column. | - |
Results:
Name | Type | Description |
---|---|---|
type |
ColumnType |
The type of the column. |
Examples:
pipeline example {
val table = Table({"a": [1, 2, 3], "b": [4, 5, 6]});
out table.getColumnType("a");
}
Stub code in Table.sdsstub
hasColumn
¶
Check if the table has a column with a specific name.
Parameters:
Name | Type | Description | Default |
---|---|---|---|
name |
String |
The name of the column. | - |
Results:
Name | Type | Description |
---|---|---|
hasColumn |
Boolean |
Whether the table has a column with the specified name. |
Examples:
pipeline example {
val table = Table({"a": [1, 2, 3], "b": [4, 5, 6]});
out table.hasColumn("a");
out table.hasColumn("c");
}
Stub code in Table.sdsstub
inverseTransformTable
¶
Inverse-transform the table by a fitted, invertible transformer and return the result as a new table.
Notes:
- The original table is not modified.
- Depending on the transformer, this operation might fully load the data into memory, which can be expensive.
Parameters:
Name | Type | Description | Default |
---|---|---|---|
fittedTransformer |
InvertibleTableTransformer |
The fitted, invertible transformer to apply. | - |
Results:
Name | Type | Description |
---|---|---|
newTable |
Table |
The inverse-transformed table. |
Examples:
pipeline example {
val table = Table({"a": [1, 2, 3]});
val transformer, val transformedTable = RangeScaler(min = 0, max = 1).fitAndTransform(table);
out transformedTable.inverseTransformTable(transformer);
}
Stub code in Table.sdsstub
join
¶
Join the current table (left table) with another table (right table) and return the result as a new table.
Rows are matched if the values in the specified columns are equal. The parameter left_names
controls which
columns are used for the left table, and right_names
does the same for the right table.
There are various types of joins, specified by the mode
parameter:
"inner"
: Keep only rows that have matching values in both tables."left"
: Keep all rows from the left table and the matching rows from the right table. Cells with no match are marked as missing values."right"
: Keep all rows from the right table and the matching rows from the left table. Cells with no match are marked as missing values."full"
: Keep all rows from both tables. Cells with no match are marked as missing values.
Note: The original tables are not modified.
Parameters:
Name | Type | Description | Default |
---|---|---|---|
rightTable |
Table |
The table to join with the left table. | - |
leftNames |
union<List<String>, String> |
Names of columns to join on in the left table. | - |
rightNames |
union<List<String>, String> |
Names of columns to join on in the right table. | - |
mode |
literal<"inner", "left", "right", "full"> |
Specify which type of join you want to use. | "inner" |
Results:
Name | Type | Description |
---|---|---|
newTable |
Table |
The table with the joined table. |
Examples:
pipeline example {
val table1 = Table({"a": [1, 2], "b": [true, false]});
val table2 = Table({"c": [1, 3], "d": ["a", "b"]});
out table1.join(table2, "a", "c", mode="inner");
out table1.join(table2, "a", "c", mode="left");
out table1.join(table2, "a", "c", mode="right");
out table1.join(table2, "a", "c", mode="full");
}
Stub code in Table.sdsstub
removeColumns
¶
Remove the specified columns from the table and return the result as a new table.
Note: The original table is not modified.
Parameters:
Name | Type | Description | Default |
---|---|---|---|
selector |
union<List<String>, String> |
The columns to remove. | - |
ignoreUnknownNames |
Boolean |
If set to true, columns that are not present in the table will be ignored. If set to false, an error will be raised if any of the specified columns do not exist. | false |
Results:
Name | Type | Description |
---|---|---|
newTable |
Table |
The table with the columns removed. |
Examples:
pipeline example {
val table = Table({"a": [1, 2, 3], "b": [4, 5, 6]});
out table.removeColumns("a");
out table.removeColumns(["c"], ignoreUnknownNames = true);
}
Stub code in Table.sdsstub
removeColumnsWithMissingValues
¶
Remove columns with too many missing values and return the result as a new table.
How many missing values are allowed is determined by the missing_value_ratio_threshold
parameter. A column is
removed if its missing value ratio is greater than the threshold. By default, a column is removed if it contains
any missing values.
Notes:
- The original table is not modified.
- This operation must fully load the data into memory, which can be expensive.
Results:
Name | Type | Description |
---|---|---|
newTable |
Table |
The table without columns that contain too many missing values. |
Examples:
pipeline example {
val table = Table({"a": [1, 2, 3], "b": [4, 5, null]});
out table.removeColumnsWithMissingValues();
}
Stub code in Table.sdsstub
removeDuplicateRows
¶
Remove duplicate rows and return the result as a new table.
Note: The original table is not modified.
Results:
Name | Type | Description |
---|---|---|
newTable |
Table |
The table without duplicate rows. |
Examples:
pipeline example {
val table = Table({"a": [1, 2, 2], "b": [4, 5, 5]});
out table.removeDuplicateRows();
}
Stub code in Table.sdsstub
removeNonNumericColumns
¶
Remove non-numeric columns and return the result as a new table.
Note: The original table is not modified.
Results:
Name | Type | Description |
---|---|---|
newTable |
Table |
The table without non-numeric columns. |
Examples:
pipeline example {
val table = Table({"a": [1, 2, 3], "b": ["4", "5", "6"]});
out table.removeNonNumericColumns();
}
Stub code in Table.sdsstub
removeRows
¶
Remove rows that satisfy a condition and return the result as a new table.
Note: The original table is not modified.
Parameters:
Name | Type | Description | Default |
---|---|---|---|
predicate |
(row: Row) -> (satisfiesPredicate: Cell<Boolean?>) |
The function that determines which rows to remove. | - |
Results:
Name | Type | Description |
---|---|---|
newTable |
Table |
The table without the specified rows. |
Examples:
pipeline example {
val table = Table({"a": [1, 2, 3], "b": [4, 5, 6]});
out table.removeRows((row) -> row["a"] == 2);
}
Stub code in Table.sdsstub
removeRowsByColumn
¶
Remove rows that satisfy a condition on a specific column and return the result as a new table.
Note: The original table is not modified.
Parameters:
Name | Type | Description | Default |
---|---|---|---|
name |
String |
The name of the column. | - |
predicate |
(cell: Cell<Any>) -> (satisfiesPredicate: Cell<Boolean?>) |
The function that determines which rows to remove. | - |
Results:
Name | Type | Description |
---|---|---|
newTable |
Table |
The table without the specified rows. |
Examples:
pipeline example {
val table = Table({"a": [1, 2, 3], "b": [4, 5, 6]});
out table.removeRowsByColumn("a", (cell) -> cell == 2);
}
Stub code in Table.sdsstub
removeRowsWithMissingValues
¶
Remove rows that contain missing values in the specified columns and return the result as a new table.
The resulting table no longer has missing values in the specified columns. Be aware that this method can discard a lot of data. Consider first removing columns with many missing values, or using one of the imputation methods (see "Related" section).
Note: The original table is not modified.
Parameters:
Name | Type | Description | Default |
---|---|---|---|
selector |
union<List<String>, String?> |
The columns to check. If null, all columns are checked. | null |
Results:
Name | Type | Description |
---|---|---|
newTable |
Table |
The table without rows that contain missing values in the specified columns. |
Examples:
pipeline example {
val table = Table({"a": [1, null, 3], "b": [4, 5, null]});
out table.removeRowsWithMissingValues();
out table.removeRowsWithMissingValues(selector = ["b"]);
}
Stub code in Table.sdsstub
removeRowsWithOutliers
¶
Remove rows that contain outliers in the specified columns and return the result as a new table.
Whether a value is an outlier in a column is determined by its z-score. The z-score the distance of the value from the mean of the column divided by the standard deviation of the column. If the z-score is greater than the given threshold, the value is considered an outlier. Missing values are ignored during the calculation of the z-score.
The z-score is only defined for numeric columns. Non-numeric columns are ignored, even if they are specified in
column_names
.
Notes:
- The original table is not modified.
- This operation must fully load the data into memory, which can be expensive.
Parameters:
Name | Type | Description | Default |
---|---|---|---|
selector |
union<List<String>, String?> |
The columns to check. If null, all columns are checked. | null |
zScoreThreshold |
Float |
The z-score threshold for detecting outliers. Must be greater than or equal to 0. | 3 |
Results:
Name | Type | Description |
---|---|---|
newTable |
Table |
The table without rows that contain outliers in the specified columns. |
Examples:
pipeline example {
val table = Table(
{
"a": [1, 2, 3, 4, 5, 6, 1000, null],
"b": [1, 2, 3, 4, 5, 6, 7, 8],
}
);
out table.removeRowsWithOutliers(zScoreThreshold = 2);
}
Stub code in Table.sdsstub
renameColumn
¶
Rename a column and return the result as a new table.
Note: The original table is not modified.
Parameters:
Name | Type | Description | Default |
---|---|---|---|
oldName |
String |
The name of the column to rename. | - |
newName |
String |
The new name of the column. | - |
Results:
Name | Type | Description |
---|---|---|
newTable |
Table |
The table with the column renamed. |
Examples:
pipeline example {
val table = Table({"a": [1, 2, 3], "b": [4, 5, 6]});
out table.renameColumn("a", "c");
}
Stub code in Table.sdsstub
replaceColumn
¶
Replace a column with zero or more columns and return the result as a new table.
Note: The original table is not modified.
Parameters:
Name | Type | Description | Default |
---|---|---|---|
oldName |
String |
The name of the column to replace. | - |
newColumns |
union<Column<Any>, List<Column<Any>>, Table> |
The new columns. | - |
Results:
Name | Type | Description |
---|---|---|
newTable |
Table |
The table with the column replaced. |
Examples:
pipeline example {
val table = Table({"a": [1, 2, 3], "b": [4, 5, 6]});
val column1 = Column("c", [7, 8, 9]);
val column2 = Column("d", [10, 11, 12]);
out table.replaceColumn("a", []);
out table.replaceColumn("a", column1);
out table.replaceColumn("a", [column1, column2]);
}
Stub code in Table.sdsstub
selectColumns
¶
Select a subset of the columns and return the result as a new table.
Note: The original table is not modified.
Parameters:
Name | Type | Description | Default |
---|---|---|---|
selector |
union<List<String>, String> |
The columns to keep. | - |
Results:
Name | Type | Description |
---|---|---|
newTable |
Table |
The table with only a subset of the columns. |
Examples:
pipeline example {
val table = Table({"a": [1, 2, 3], "b": [4, 5, 6]});
out table.selectColumns("a");
}
Stub code in Table.sdsstub
shuffleRows
¶
Shuffle the rows and return the result as a new table.
Notes:
- The original table is not modified.
- This operation must fully load the data into memory, which can be expensive.
Parameters:
Name | Type | Description | Default |
---|---|---|---|
randomSeed |
Int |
The seed for the pseudorandom number generator. | 0 |
Results:
Name | Type | Description |
---|---|---|
newTable |
Table |
The table with the rows shuffled. |
Examples:
Stub code in Table.sdsstub
sliceRows
¶
Slice the rows and return the result as a new table.
Note: The original table is not modified.
Parameters:
Name | Type | Description | Default |
---|---|---|---|
start |
Int |
The start index of the slice. Nonnegative indices are counted from the beginning (starting at 0), negative indices from the end (starting at -1). | 0 |
length |
Int? |
The length of the slice. If null, the slice contains all rows starting from start . Must greater than or equal to 0. |
null |
Results:
Name | Type | Description |
---|---|---|
newTable |
Table |
The table with the slice of rows. |
Examples:
pipeline example {
val table = Table({"a": [1, 2, 3], "b": [4, 5, 6]});
out table.sliceRows(start = 1);
out table.sliceRows(start = 1, length = 1);
}
Stub code in Table.sdsstub
sortRows
¶
Sort the rows by a custom function and return the result as a new table.
Note: The original table is not modified.
Parameters:
Name | Type | Description | Default |
---|---|---|---|
keySelector |
(row: Row) -> (key: Cell<Any?>) |
The function that selects the key to sort by. | - |
descending |
Boolean |
Whether to sort in descending order. | false |
Results:
Name | Type | Description |
---|---|---|
newTable |
Table |
The table with the rows sorted. |
Examples:
pipeline example {
val table = Table({"a": [2, 1, 3], "b": [1, 1, 2]});
out table.sortRows((row) -> row["a"] - row["b"]);
}
Stub code in Table.sdsstub
sortRowsByColumn
¶
Sort the rows by a specific column and return the result as a new table.
Note: The original table is not modified.
Parameters:
Name | Type | Description | Default |
---|---|---|---|
name |
String |
The name of the column to sort by. | - |
descending |
Boolean |
Whether to sort in descending order. | false |
Results:
Name | Type | Description |
---|---|---|
newTable |
Table |
The table with the rows sorted by the specified column. |
Examples:
pipeline example {
val table = Table({"a": [2, 1, 3], "b": [1, 1, 2]});
out table.sortRowsByColumn("a");
}
Stub code in Table.sdsstub
splitRows
¶
Create two tables by splitting the rows of the current table.
The first table contains a percentage of the rows specified by percentage_in_first
, and the second table
contains the remaining rows. By default, the rows are shuffled before splitting. You can disable this by setting
shuffle
to false.
Notes:
- The original table is not modified.
- This operation must fully load the data into memory, which can be expensive.
Parameters:
Name | Type | Description | Default |
---|---|---|---|
percentageInFirst |
Float |
The percentage of rows to include in the first table. Must be between 0 and 1. | - |
shuffle |
Boolean |
Whether to shuffle the rows before splitting. | true |
randomSeed |
Int |
The seed for the pseudorandom number generator used for shuffling. | 0 |
Results:
Name | Type | Description |
---|---|---|
firstTable |
Table |
The first table. |
secondTable |
Table |
The second table. |
Examples:
pipeline example {
val table = Table({"a": [1, 2, 3, 4, 5], "b": [6, 7, 8, 9, 10]});
out table.splitRows(0.6);
}
Stub code in Table.sdsstub
summarizeStatistics
¶
Return a table with important statistics about this table.
API Stability
Do not rely on the exact output of this method. In future versions, we may change the displayed statistics without prior notice.
Results:
Name | Type | Description |
---|---|---|
statistics |
Table |
The table with statistics. |
Examples:
Stub code in Table.sdsstub
toColumns
¶
Return the data of the table as a list of columns.
Results:
Name | Type | Description |
---|---|---|
columns |
List<Column<Any?>> |
The columns of the table. |
Examples:
Stub code in Table.sdsstub
toCsvFile
¶
Write the table to a CSV file.
If the file and/or the parent directories do not exist, they will be created. If the file exists already, it will be overwritten.
Parameters:
Name | Type | Description | Default |
---|---|---|---|
path |
String |
The path to the CSV file. If the file extension is omitted, it is assumed to be ".csv". | - |
Examples:
pipeline example {
val table = Table({"a": [1, 2, 3], "b": [4, 5, 6]});
table.toCsvFile("./src/resources/toCsvFile.csv");
}
Stub code in Table.sdsstub
toJsonFile
¶
Write the table to a JSON file.
If the file and/or the parent directories do not exist, they will be created. If the file exists already, it will be overwritten.
Note: This operation must fully load the data into memory, which can be expensive.
Parameters:
Name | Type | Description | Default |
---|---|---|---|
path |
String |
The path to the JSON file. If the file extension is omitted, it is assumed to be ".json". | - |
Examples:
pipeline example {
val table = Table({"a": [1, 2, 3], "b": [4, 5, 6]});
table.toJsonFile("./src/resources/toJsonFile.json");
}
Stub code in Table.sdsstub
toMap
¶
Return a map from column names to column values.
Note: This operation must fully load the data into memory, which can be expensive.
Results:
Name | Type | Description |
---|---|---|
map |
Map<String, List<Any>> |
The map representation of the table. |
Examples:
Stub code in Table.sdsstub
toParquetFile
¶
Write the table to a Parquet file.
If the file and/or the parent directories do not exist, they will be created. If the file exists already, it will be overwritten.
Parameters:
Name | Type | Description | Default |
---|---|---|---|
path |
String |
The path to the Parquet file. If the file extension is omitted, it is assumed to be ".parquet". | - |
Examples:
pipeline example {
val table = Table({"a": [1, 2, 3], "b": [4, 5, 6]});
table.toParquetFile("./src/resources/toParquetFile.parquet");
}
Stub code in Table.sdsstub
toTabularDataset
¶
Return a new TabularDataset
with columns marked as a target, feature, or extra.
- The target column is the column that a model should predict.
- Feature columns are columns that a model should use to make predictions.
- Extra columns are columns that are neither feature nor target. They are ignored by models and can be used to provide additional context. An ID or name column is a common example.
Feature columns are implicitly defined as all columns except the target and extra columns. If no extra columns are specified, all columns except the target column are used as features.
Parameters:
Name | Type | Description | Default |
---|---|---|---|
targetName |
String |
The name of the target column. | - |
extraNames |
union<List<String>, String?> |
Names of the columns that are neither features nor target. If null, no extra columns are used, i.e. all but the target column are used as features. | null |
Results:
Name | Type | Description |
---|---|---|
dataset |
TabularDataset |
- |
Examples:
pipeline example {
val table = Table(
{
"extra": [1, 2, 3],
"feature": [4, 5, 6],
"target": [7, 8, 9],
},
);
out table.toTabularDataset("target", extraNames="extra");
}
Stub code in Table.sdsstub
transformColumns
¶
Transform columns with a custom function and return the result as a new table.
Note: The original table is not modified.
Parameters:
Name | Type | Description | Default |
---|---|---|---|
selector |
union<List<String>, String> |
The names of the columns to transform. | - |
transformer |
(cell: Cell<Any?>, row: Row) -> (result: Cell<Any?>) |
The function that computes the new values. It may take either a single cell or a cell and the entire row as arguments (see examples). | - |
Results:
Name | Type | Description |
---|---|---|
newTable |
Table |
The table with the transformed column. |
Examples:
pipeline example {
val table = Table({"a": [1, 2, 3], "b": [4, 5, 6]});
out table.transformColumns("a", (cell, row) -> cell + 1);
out table.transformColumns(["a", "b"], (cell, row) -> cell + 1);
out table.transformColumns("a", (cell, row) -> cell + row["b"]);
}
Stub code in Table.sdsstub
transformTable
¶
Transform the table with a fitted transformer and return the result as a new table.
Notes:
- The original table is not modified.
- Depending on the transformer, this operation might fully load the data into memory, which can be expensive.
Parameters:
Name | Type | Description | Default |
---|---|---|---|
fittedTransformer |
TableTransformer |
The fitted transformer to apply. | - |
Results:
Name | Type | Description |
---|---|---|
newTable |
Table |
The transformed table. |
Examples:
pipeline example {
val table = Table({"a": [1, 2, 3]});
val transformer = RangeScaler(min = 0, max = 1).fit(table);
out table.transformTable(transformer);
}
Stub code in Table.sdsstub
fromColumns
¶
Create a table from columns.
Parameters:
Name | Type | Description | Default |
---|---|---|---|
columns |
union<Column<Any?>, List<Column<Any?>>> |
The columns. | - |
Results:
Name | Type | Description |
---|---|---|
table |
Table |
The created table. |
Examples:
pipeline example {
val a = Column("a", [1, 2, 3]);
val b = Column("b", [4, 5, 6]);
out Table.fromColumns([a, b]);
}
Stub code in Table.sdsstub
fromCsvFile
¶
Create a table from a CSV file.
Parameters:
Name | Type | Description | Default |
---|---|---|---|
path |
String |
The path to the CSV file. If the file extension is omitted, it is assumed to be ".csv". | - |
separator |
String |
The separator between the values in the CSV file. | "," |
Results:
Name | Type | Description |
---|---|---|
table |
Table |
The created table. |
Examples:
Stub code in Table.sdsstub
fromJsonFile
¶
Create a table from a JSON file.
Parameters:
Name | Type | Description | Default |
---|---|---|---|
path |
String |
The path to the JSON file. If the file extension is omitted, it is assumed to be ".json". | - |
Results:
Name | Type | Description |
---|---|---|
table |
Table |
The created table. |
Examples:
Stub code in Table.sdsstub
fromMap
¶
Create a table from a map that maps column names to column values.
Parameters:
Name | Type | Description | Default |
---|---|---|---|
data |
Map<String, List<Any>> |
The data. | - |
Results:
Name | Type | Description |
---|---|---|
table |
Table |
The generated table. |
Examples:
Stub code in Table.sdsstub
fromParquetFile
¶
Create a table from a Parquet file.
Parameters:
Name | Type | Description | Default |
---|---|---|---|
path |
String |
The path to the Parquet file. If the file extension is omitted, it is assumed to be ".parquet". | - |
Results:
Name | Type | Description |
---|---|---|
table |
Table |
The created table. |
Examples: