Discussion about limits in Excel (15 decimal digits maximum) with my friend caused inspiration for writing few words about basic number magic within Bash command line.
As Pi precision is one of classic benchmark, let´s try it. You can find many information about Pi number (there and there), anyway it´s always good to know something about bc in *nix environment. Now we can write directly into command line something like this:
ji@linux-bfq8:~> time echo "scale=1500; 4*a(1)" | bc -l
3.141592653589793238462643383279502884197169399375105820974944592307\
81640628620899862803482534211706798214808651328230664709384460955058\
22317253594081284811174502841027019385211055596446229489549303819644\
28810975665933446128475648233786783165271201909145648566923460348610\
45432664821339360726024914127372458700660631558817488152092096282925\
40917153643678925903600113305305488204665213841469519415116094330572\
70365759591953092186117381932611793105118548074462379962749567351885\
75272489122793818301194912983367336244065664308602139494639522473719\
07021798609437027705392171762931767523846748184676694051320005681271\
45263560827785771342757789609173637178721468440901224953430146549585\
37105079227968925892354201995611212902196086403441815981362977477130\
99605187072113499999983729780499510597317328160963185950244594553469\
08302642522308253344685035261931188171010003137838752886587533208381\
42061717766914730359825349042875546873115956286388235378759375195778\
18577805321712268066130019278766111959092164201989380952572010654858\
63278865936153381827968230301952035301852968995773622599413891249721\
77528347913151557485724245415069595082953311686172785588907509838175\
46374649393192550604009277016711390098488240128583616035637076601047\
10181942955596198946767837449448255379774726847104047534646208046684\
25906949129331367702898915210475216205696602405803815019351125338243\
00355876402474964732639141992726042699227967823547816360093417216412\
19924586315030286182974555706749838505494588586926995690927210797509\
302952
real 0m1.045s
user 0m1.032s
sys 0m0.000s
ji@linux-bfq8:~>
Pi number with 1500 decimal places – not bad, right? 🙂 -l at the end is hinting bc to use standard math library (as function arctan – a() is part of it). Ok, some basics first (without any comments, I think all will be very simple):
ji@linux-bfq8:~> echo 10/3
10/3
ji@linux-bfq8:~> echo 10/3 | bc -l
3.33333333333333333333
ji@linux-bfq8:~> echo "scale=5;10/3" | bc -l
3.33333
ji@linux-bfq8:~> echo "obase=16; 255" | bc
FF
ji@linux-bfq8:~> echo "obase=2; 255" | bc
11111111
With all documentation + scripting abilities + your imagination you can handle very complex math problems with Bash. If you want to get higher, try awk or/and perl. Do you feel the infinity?……
-a-