### Commands tagged math (14) the last day the last week the last month all time sorted by date votes

• 8
seq -s* 10 |bc
· 2011-02-10 08:03:19
• expr will give you a quick way to do basic math from the CLI. Make sure you escape things like * and leave a space between operators and digits. Show Sample Output

4
expr 512 \* 7
· 2009-09-23 19:11:38
• To do hex to binary: echo 'ibase=16; obase=2; 16*16' | bc # prints: 111100100 To do 16*16 from decimal to hex: echo 'ibase=10; obase=16; 16*16' | bc # prints: 100 You get the idea... Alternatively, run bc in interactive mode (see man page) Show Sample Output

4
echo 'obase=16; C+F' | bc
· 2010-04-14 20:35:31
• Read all lines using decimal marker as point, then add all them up and outputs the result. Show Sample Output

4
awk '{a+=\$0}END{print a}' file
· 2022-08-15 23:04:31

• 2
seq 1000 | paste -sd+- | bc
· 2011-02-09 20:03:49

• 2
echo \$(( \$(echo 1 "* "{2..10}) ))
· 2011-02-10 17:09:28
• In this example, file contains five columns where first column is text. Variance is calculated for columns 2 - 5 by using perl module Statistics::Descriptive. There are many more statistical functions available in the module. Show Sample Output

1
perl -MStatistics::Descriptive -alne 'my \$stat = Statistics::Descriptive::Full->new; \$stat->add_data(@F[1..4]); print \$stat->variance' filename
· 2010-04-02 21:16:12

• 1
seq 10 | paste -sd* | bc
· 2011-02-09 19:56:12
• Same as the seq/bc solution but without bc.

1
echo \$((\$(seq -s* 10)))
· 2011-02-10 18:44:53
• Calculate pi from the infinite series 4/1 - 4/3 + 4/5 - 4/7 + ... This expansion was formulated by Gottfried Leibniz: http://en.wikipedia.org/wiki/Leibniz_formula_for_pi I helped rubenmoran create the sum of a sequence of numbers and he replied with a command for the sequence: 1 + 2 -3 + 4 ... This set me thinking. Transcendental numbers! seq provides the odd numbers 1, 3, 5 sed turns them into 4/1 4/3 4/5 paste inserts - and + bc -l does the calculation Note: 100 million iterations takes quite a while. 1 billion and I run out of memory. Show Sample Output

0
seq 1 2 99999999 | sed 's!^!4/!' | paste -sd-+ | bc -l
· 2011-02-09 23:36:07
• http://en.wikipedia.org/wiki/Pascal%27s_triangle This one's for bartonski. Enjoy. 132 characters. I'm sure we can do better. Note: after row 64 we overflow integer maths. Show Sample Output

0
for((r=1;r<10;r++));do v=1;echo -n "\$v ";for((c=1;c<\$r;c++));do v2=\$((\$(echo "\$v*(\$r-\$c)/\$c")));echo -n "\$v2 ";v=\$v2;done;echo;done
· 2011-02-10 18:38:04
• More readable version of factorial calculation using standard desktop calculator instead of bc.

0
dc -e '10 [q]sq[dd1=q1-lxx*]dsxxp'
· 2011-02-16 19:00:21

• -1
year=2010; math=`echo "\$year%4" | bc`; [ ! -z \$year ] && [ \$math -eq 0 ] && echo "\$year is leap year!" || echo "\$year isn't leap year";
· 2010-03-30 15:33:00
• I can't put the last ^2 with seq, so I reverse it to delete the last +N. So for doing sum(N^2) you have to do sum((N+1)^2). Must be a better way. Show Sample Output

-2
seq -s^2+ 11 |rev| cut -d'+' -f2- | rev | bc
· 2011-02-10 08:41:14

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