NAME¶

SYNOPSIS¶

DESCRIPTION¶

File operations:¶

transpose, reverse

Numeric Grouping operations:¶

sum, min, max, absmin, absmax

Textual/Numeric Grouping operations:¶

count, first, last, rand unique, collapse, countunique

Statistical Grouping operations:¶

mean, median, q1, q3, iqr, mode, antimode pstdev, sstdev, pvar, svar, mad, madraw pskew, sskew, pkurt, skurt, dpo, jarque

OPTIONS¶

Grouping Options:¶

-f, --full

print entire input line before op results (default: print only the grouped keys)

-g, --group=X[,Y,Z]

group via fields X,[Y,Z]

--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'

File Operation Options:¶

--no-strict

allow lines with varying number of fields

--filler=X

fill missing values with X (default %s)

General Options:¶

-t, --field-separator=X

use X instead of TAB as field delimiter

-W, --whitespace

use whitespace (one or more spaces and/or tabs) for field delimiters

-z, --zero-terminated

end lines with 0 byte, not newline

--help

display this help and exit

--version

output version information and exit

AVAILABLE OPERATIONS¶

File operations:¶

transpose

transpose rows, columns of the input file

reverse

reverse field order in each line

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

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

comma-separated sorted list of unique values

collapse

comma-separated list of all input values

countunique

number of unique/distinct values

Statistical Grouping operations¶

mean

mean of the values

median

median value

q1

1st quartile value

q3

3rd quartile value

iqr

inter-quartile range

mode

mode value (most common value)

antimode

anti-mode value (least common value)

pstdev

population standard deviation

sstdev

sample standard deviation

pvar

population variance

svar

sample variance

mad

median absolute deviation, scaled by constant 1.4826 for normal distributions

madraw

median absolute deviation, unscaled

sskew

skewness of the (sample) group

pskew

skewness of the (population) 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
    

skurt

excess Kurtosis of the (sample) group

pkurt

excess Kurtosis of the (population) group

jarque

p-value of the Jarque-Beta test for normality

dpo

p-value of the D'Agostino-Pearson Omnibus test for normality;
for 'jarque' and 'dpo' operations:
null hypothesis is normality;
low p-Values indicate non-normal data;
high p-Values indicate null-hypothesis cannot be rejected.

EXAMPLES¶

$ seq 10 |  datamash sum 1 mean 1
55  5.5

$ cat example.txt
A  10
A  5
B  9
B  11
$  datamash -g 1 sum 2 < example.txt
A  15
B  20

$ 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

$ cat example.txt | sort -k1,1 |  datamash -g 1 sum 2

# 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 devian 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
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

$ seq 6 | paste - - |  datamash reverse
2    1
4    3
6    5

$ seq 6 | paste - - |  datamash transpose
1    3    5
2    4    6

ADDITIONAL INFORMATION¶

AUTHOR¶

COPYRIGHT¶

SEE ALSO¶

info datamash