DATAMASH(1) User Commands DATAMASH(1) NAME datamash - command-line calculations SYNOPSIS datamash [OPTION] op [fld] [op fld ...] DESCRIPTION Performs numeric/string operations on input from stdin. 'op' is the operation to perform. If a primary operation is used, it must be listed first, optionally followed by other operations. 'fld' is the input field to use. 'fld' can be a number (1=first field), or a field name when using the -H or --header-in options. Multiple fields can be listed with a comma (e.g. 1,6,8). A range of fields can be listed with a dash (e.g. 2-8). Use colons for operations which require a pair of fields (e.g. 'pcov 2:6'). Primary operations: groupby, crosstab, transpose, reverse, check Line-Filtering operations: rmdup Per-Line operations: base64, debase64, md5, sha1, sha224, sha256, sha384, sha512, bin, strbin, round, floor, ceil, trunc, frac, dirname, basename, barename, extname, getnum, cut Numeric Grouping operations: sum, min, max, absmin, absmax, range Textual/Numeric Grouping operations: count, first, last, rand, unique, collapse, countunique Statistical Grouping operations: mean, geomean, harmmean, trimmean, median, q1, q3, iqr, perc, mode, antimode, pstdev, sstdev, pvar, svar, ms, rms, mad, madraw, pskew, sskew, pkurt, skurt, dpo, jarque, scov, pcov, spearson, ppearson OPTIONS Grouping Options: -C, --skip-comments skip comment lines (starting with '#' or ';' and optional whitespace) -f, --full print entire input line before op results (default: print only the grouped keys) This option is only sensible for linewise operations. Other uses are deprecated and will be removed in a future version of GNU Datamash. -g, --group=X[,Y,Z] group via fields X,[Y,Z]; equivalent to primary operation 'groupby' --header-in first input line is column headers --header-out print column headers as first line -H, --headers same as '--header-in --header-out' -i, --ignore-case ignore upper/lower case when comparing text; this affects grouping, and string operations -s, --sort sort the input before grouping; this removes the need to manually pipe the input through 'sort' -c, --collapse-delimiter=X use X to separate elements in collapse and unique lists (default: comma) File Operation Options: --no-strict allow lines with varying number of fields --filler=X fill missing values with X (default N/A) General Options: -t, --field-separator=X use X instead of TAB as field delimiter --format=FORMAT print numeric values with printf style floating-point FORMAT. --output-delimiter=X use X instead as output field delimiter (default: use same delimiter as -t/-W) --narm skip NA/NaN values -R, --round=N round numeric output to N decimal places -W, --whitespace use whitespace (one or more spaces and/or tabs) for field delimiters -z, --zero-terminated end lines with 0 byte, not newline --sort-cmd=/path/to/sort Alternative sort(1) to use. --help display this help and exit --version output version information and exit AVAILABLE OPERATIONS Primary Operations Primary operations affect the way the file is processed. If used, the primary operation must be listed first. If primary operation is not listed the entire file is processed - either line-by-line (for 'per- line' operations) or all lines as one group (for grouping operations). See Examples section below. groupby X,Y,... op fld ... group the file by given fields. Equivalent to option '-g'. For each group perform operation op on field fld. crosstab X,Y [op fld ...] cross-tabulate a file by two fields (cross-tabulation is also known as pivot tables). If no operation is specified, counts how many incidents exist of X,Y. transpose transpose rows, columns of the input file reverse reverse field order in each line check [N lines] [N fields] verify the input file has same number of fields in all lines, or the expected number of lines/fields. number of lines and fields are printed to STDOUT. Exits with non-zero code and prints the offending line if there's a mismatch in the number of lines/ fields. Line-Filtering operations rmdup remove lines with duplicated key value Per-Line operations base64 Encode the field as base64 debase64 Decode the field as base64, exit with error if invalid base64 string md5/sha1/sha224/sha256/sha384/sha512 Calculate md5/sha1/sha224/sha256/sha384/sha512 hash of the field value bin[:BUCKET-SIZE] bin numeric values into buckets of size BUCKET-SIZE (defaults to 100). strbin[:BUCKET-SIZE] hashes the input and returns a numeric integer value between zero and BUCKET-SIZE (defaults to 10). round/floor/ceil/trunc/frac numeric rounding operations. round (round half away from zero), floor (round down), ceil (ceiling, round up), trunc (truncate, round towards zero), frac (fraction, return fraction part of a decimal-point value). dirname/basename extract the directory name and the base file name from a given string (same as to dirname(1) and basename(1)). extname extract the extension of the file name (without the '.'). barename extract the base file name without the extension. getnum[:TYPE] extract a number from the field. TYPE is optional single letter option n/i/d/p/h/o (see examples below). cut/echo copy input field to output field (similar to cut(1)). The echo command is simply an alias to cut. Numeric Grouping operations sum sum the of values min minimum value max maximum value absmin minimum of the absolute values absmax maximum of the absolute values range the values range (max-min) Textual/Numeric Grouping operations count count number of elements in the group first the first value of the group last the last value of the group rand one random value from the group unique/uniq comma-separated sorted list of unique values The uniq command is simply an alias to unique. collapse comma-separated list of all input values countunique number of unique/distinct values Statistical Grouping operations A p/s prefix indicates the variant: population or sample. Typically, the sample variant is equivalent with GNU R's internal functions (e.g datamash's sstdev operation is equivalent to R's sd() function). mean mean of the values geomean geometric mean of the values harmmean harmonic mean of the values trimmean[:PERCENT] trimmed mean of the values. PERCENT should be between 0 and 0.5. (trimmean:0 is equivalent to mean. trimmean:0.5 is equivalent to median). ms mean square of the values rms root mean square of the values median median value q1 1st quartile value q3 3rd quartile value iqr inter-quartile range perc[:PERCENTILE] percentile value PERCENTILE (defaults to 95). mode mode value (most common value) antimode anti-mode value (least common value) pstdev/sstdev population/sample standard deviation pvar/svar population/sample variance mad median absolute deviation, scaled by constant 1.4826 for normal distributions madraw median absolute deviation, unscaled pskew/sskew skewness of the group values x reported by 'sskew' and 'pskew' operations: x > 0 - positively skewed / skewed right 0 > x - negatively skewed / skewed left x > 1 - highly skewed right 1 > x > 0.5 - moderately skewed right 0.5 > x > -0.5 - approximately symmetric -0.5 > x > -1 - moderately skewed left -1 > x - highly skewed left pkurt/skurt excess Kurtosis of the group jarque/dpo p-value of the Jarque-Beta (jarque) and D'Agostino-Pearson Omnibus (dpo) tests for normality: null hypothesis is normality; low p-Values indicate non-normal data; high p-Values indicate null-hypothesis cannot be rejected. pcov/scov [X:Y] covariance of fields X and Y ppearson/spearson [X:Y] Pearson product-moment correlation coefficient [Pearson's R] of fields X and Y EXAMPLES Basic usage Print the sum and the mean of values from field 1: $ seq 10 | datamash sum 1 mean 1 55 5.5 Group input based on field 1, and sum values (per group) on field 2: $ cat example.txt A 10 A 5 B 9 B 11 $ datamash -g 1 sum 2 < example.txt A 15 B 20 $ datamash groupby 1 sum 2 < example.txt A 15 B 20 Unsorted input must be sorted (with '-s'): $ cat example.txt A 10 C 4 B 9 C 1 A 5 B 11 $ datamash -s -g1 sum 2 < example.txt A 15 B 20 C 5 Which is equivalent to: $ cat example.txt | sort -k1,1 | datamash -g 1 sum 2 Header lines Use -H (--headers) if the input file has a header line: # Given a file with student name, field, test score... $ head -n5 scores_h.txt Name Major Score Shawn Engineering 47 Caleb Business 87 Christian Business 88 Derek Arts 60 # Calculate the mean and standard deviation for each major $ datamash --sort --headers --group 2 mean 3 pstdev 3 < scores_h.txt (or use short form) $ datamash -sH -g2 mean 3 pstdev 3 < scores_h.txt (or use named fields) $ datamash -sH -g Major mean Score pstdev Score < scores_h.txt GroupBy(Major) mean(Score) pstdev(Score) Arts 68.9 10.1 Business 87.3 4.9 Engineering 66.5 19.1 Health-Medicine 90.6 8.8 Life-Sciences 55.3 19.7 Social-Sciences 60.2 16.6 Field names must be escaped with a backslash if they start with a digit or contain special characters (dash/minus, colons, commas). Note the interplay between escaping with backslash and shell quoting. The following equivalent command sum the values of a field named "FOO-BAR": $ datamash -H sum FOO\\-BAR < input.txt $ datamash -H sum 'FOO\-BAR' < input.txt $ datamash -H sum "FOO\\-BAR" < input.txt Skipping comment lines Use -C (--skip-comments) to skip lines starting with '#' or ';' characters (and optional whitespace before them): $ cat in.txt #foo 3 bar 5 ;baz 7 $ datamash sum 2 < in.txt 15 $ datamash -C sum 2 < in.txt 5 Multiple fields Use comma or dash to specify multiple fields. The following are equivalent: $ seq 9 | paste - - - 1 2 3 4 5 6 7 8 9 $ seq 9 | paste - - - | datamash sum 1 sum 2 sum 3 12 15 18 $ seq 9 | paste - - - | datamash sum 1,2,3 12 15 18 $ seq 9 | paste - - - | datamash sum 1-3 12 15 18 Rounding The following demonstrate the different rounding operations: $ ( echo X ; seq -1.25 0.25 1.25 ) \ | datamash --full -H round 1 ceil 1 floor 1 trunc 1 frac 1 X round(X) ceil(X) floor(X) trunc(X) frac(X) -1.25 -1 -1 -2 -1 -0.25 -1.00 -1 -1 -1 -1 0 -0.75 -1 0 -1 0 -0.75 -0.50 -1 0 -1 0 -0.5 -0.25 0 0 -1 0 -0.25 0.00 0 0 0 0 0 0.25 0 1 0 0 0.25 0.50 1 1 0 0 0.5 0.75 1 1 0 0 0.75 1.00 1 1 1 1 0 1.25 1 2 1 1 0.25 Reversing fields $ seq 6 | paste - - | datamash reverse 2 1 4 3 6 5 Transposing a file $ seq 6 | paste - - | datamash transpose 1 3 5 2 4 6 Removing Duplicated lines Remove lines with duplicate key value from field 1 (Unlike first,last operations, rmdup is much faster and does not require sorting the file with -s): # Given a list of files and sample IDs: $ cat INPUT SampleID File 2 cc.txt 3 dd.txt 1 ab.txt 2 ee.txt 3 ff.txt # Remove lines with duplicated Sample-ID (field 1): $ datamash rmdup 1 < INPUT # or use named field: $ datamash -H rmdup SampleID < INPUT SampleID File 2 cc.txt 3 dd.txt 1 ab.txt Checksums Calculate the sha1 hash value of each TXT file, after calculating the sha1 value of each file's content: $ sha1sum *.txt | datamash -Wf sha1 2 Check file structure Check the structure of the input file: ensure all lines have the same number of fields, or expected number of lines/fields: $ seq 10 | paste - - | datamash check && echo ok || echo fail 5 lines, 2 fields ok $ seq 13 | paste - - - | datamash check && echo ok || echo fail line 4 (3 fields): 10 11 12 line 5 (2 fields): 13 datamash: check failed: line 5 has 2 fields (previous line had 3) fail $ seq 10 | paste - - | datamash check 2 fields 5 lines 5 lines, 2 fields $ seq 10 | paste - - | datamash check 4 fields line 1 (2 fields): 1 2 datamash: check failed: line 1 has 2 fields (expecting 4) $ seq 10 | paste - - | datamash check 7 lines datamash: check failed: input had 5 lines (expecting 7) Cross-Tabulation Cross-tabulation compares the relationship between two fields. Given the following input file: $ cat input.txt a x 3 a y 7 b x 21 a x 40 Show cross-tabulation between the first field (a/b) and the second field (x/y) - counting how many times each pair appears (note: sorting is required): $ datamash -s crosstab 1,2 < input.txt x y a 2 1 b 1 N/A An optional grouping operation can be used instead of counting: $ datamash -s crosstab 1,2 sum 3 < input.txt x y a 43 7 b 21 N/A $ datamash -s crosstab 1,2 unique 3 < input.txt x y a 3,40 7 b 21 N/A Binning numeric values Bin input values into buckets of size 5: $ ( echo X ; seq -10 2.5 10 ) \ | datamash -H --full bin:5 1 X bin(X) -10.0 -10 -7.5 -10 -5.0 -5 -2.5 -5 0.0 0 2.5 0 5.0 5 7.5 5 10.0 10 Binning string values Hash any input value into a numeric integer. A typical usage would be to split an input file into N chunks, ensuring that all values of a certain key will be stored in the same chunk: $ cat input.txt PatientA 10 PatientB 11 PatientC 12 PatientA 14 PatientC 15 Each patient ID is hashed into a bin between 0 and 9 and printed in the last field: $ datamash --full strbin 1 < input.txt PatientA 10 5 PatientB 11 6 PatientC 12 7 PatientA 14 5 PatientC 15 7 Splitting the input into chunks can be done with awk: $ cat input.txt \ | datamash --full strbin 1 \ | awk '{print > $NF ".txt"}' Extracting numbers with getnum The 'getnum' operation extracts a numeric value from the field: $ echo zoom-123.45xyz | datamash getnum 1 123.45 getnum accepts an optional single-letter TYPE option: getnum:n - natural numbers (positive integers, including zero) getnum:i - integers getnum:d - decimal point numbers getnum:p - positive decimal point numbers (this is the default) getnum:h - hex numbers getnum:o - octal numbers Examples: $ echo zoom-123.45xyz | datamash getnum 1 123.45 $ echo zoom-123.45xyz | datamash getnum:n 1 123 $ echo zoom-123.45xyz | datamash getnum:i 1 -123 $ echo zoom-123.45xyz | datamash getnum:d 1 123.45 $ echo zoom-123.45xyz | datamash getnum:p 1 -123.45 # Hex 0x123 = 291 Decimal $ echo zoom-123.45xyz | datamash getnum:h 1 291 # Octal 0123 = 83 Decimal $ echo zoom-123.45xyz | datamash getnum:o 1 83 ADDITIONAL INFORMATION See GNU Datamash Website (https://www.gnu.org/software/datamash) ENVIRONMENT LC_NUMERIC decimal-point character and thousands separator AUTHOR Written by Assaf Gordon, Tim Rice, Shawn Wagner, Erik Auerswald. COPYRIGHT Copyright (C) 2022 Assaf Gordon and Tim Rice License GPLv3+: GNU GPL version 3 or later . This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. SEE ALSO The full documentation for datamash is maintained as a Texinfo manual. If the info and datamash programs are properly installed at your site, the command info datamash should give you access to the complete manual. datamash 1.8-dirty July 2022 DATAMASH(1)