bc

I need 'bc' to divide a number and give me not only the floor but also the remainder. For instance 'bc' gives me '2' if I do '5/2'. I'd really want something like '2.5' Maybe this isn't even possible? scale = 20 It sets the number of decimal places. $ bc bc 1.06 Copyright 1991-1994, 1997, 1998, 2000 Free Software Foundation, Inc. This is free software with ABSOLUTELY NO WARRANTY. For details type `warranty'. 355/113 3 scale=20 355/113 3.14159292035398230088 quit $ 来源： https://stackoverflow.com/questions/10324157/how-to-get-a-decimal-number-when-dividing-in-bc

I stumbled over a curious bug, I think: I tried to read "512" as a number to base 6, and output it as base 16: echo "ibase=6;obase=16;512" | bc 161 As you can see, the output is 161, but it should be bc (sic!). I tried with base 10: echo "ibase=6;obase=10;512" | bc 512 The value is unchanged. Curious! Default obase is 10. If I omit it: echo "ibase=6;512" | bc 188 Well, that seems right. In a two step process, it works: echo "obase=16;"$(echo "ibase=6;512" | bc) | bc BC So I made a script for different bases, but it keeps me puzzled: for ib in {6,8,10,16}; do echo $ib; for ob in {10,16}; do

I want to compute an average with 3 decimal figures, rounded to nearest, using bc . For example: average of 3, 3 and 5 should yield 3.667 and average of 3, 3 and 4 should yield 3.333 I tried: echo "scale=3; $sum/$n+0.0005" | bc but scale doesn't behave as I expect. What can I do to solve my problem? Your trick to add 0.0005 is not a bad idea. Though, it doesn't quite work that way. scale is used internally when bc performs some operations (like divisions). In your case, it would be better to perform the division first, maybe using a large scale or the -l switch to bc 1 (if your version

This is the first time I am using bc. I want to calculate the log (base 10) of a number. How do I this? Ray Toal Invoke bc with the -l option (to enable the math library) like so $ echo 'l(100)/l(10)' | bc -l 2.00000000000000000000 Use the l function which is the natural log. Take the log of the number you are interested in then divide by the natural log of 10. the logarithm of x in respect to base b can be computed given any logarithm function to an arbitrary base k -- that's actually pretty cool! log_b(x) = log_k(x) / log_k(b) e.g. log_b(x) = ln(x) / ln(b) if b=10: log_10(x) = ln(x) / ln(10)

bc doesn't like numbers expressed in scientific notation (aka exponential notation). $ echo "3.1e1*2" | bc -l (standard_in) 1: parse error but I need to use it to handle a few records that are expressed in this notation. Is there a way to get bc to understand exponential notation? If not, what can I do to translate them into a format that bc will understand? Ferdinando Randisi Unfortunately, bc doesn't support scientific notation. However, it can be translated into a format that bc can handle, using extended regex as per POSIX in sed: sed -E 's/([+-]?[0-9.]+)[eE]\+?(-?)([0-9]+)/(\1*10^\2\3)/g'