Script programming and significant figures

Question

I'm currently toying around with making scripts using tcsh and Ive noticed: If you do division it only outputs as many significant figures as the arguments going in

i.e. ( the numbers are the entered arguments):

2/4 outputs 0
4/2 outputs 2
22/2 outputs 11
1/8 outputs 0
9/2 outputs 4

So how does one alter this so 1/8= 0.125, 2/4 = 0.5, 9/2 = 4.5 etc??

GNU/Linux shells can only perform integer division. There are other options, however: http://unix.stackexchange.com/questions/40786/how-to-do-integer-float-calculations-in-bash-or-other-languages-frameworks — admdrew, Oct 08 '14 at 17:49
possible duplicate of [how can I get a float division in bash?](http://stackoverflow.com/questions/12722095/how-can-i-get-a-float-division-in-bash) — admdrew, Oct 08 '14 at 17:50

score 0 · Answer 1 · answered Oct 08 '14 at 19:01

0

Use the arbitrary precision calculator bc and set scale to the precision you want:

 $ bc -e 'scale=10;1/8;4/5; scale=30; 1/31'
 .1250000000
 .8000000000
 .032258064516129032258064516129

answered Oct 08 '14 at 19:01

Jens

69,818
15
125
179

score -1 · Answer 2 · answered Oct 08 '14 at 17:50

-1

You have to provide the memory space that you need by requesting the DATA TYPE for your variable. If you set your answer to a variable of type char, there will be only space for one character. If you set your variable type to float, there will be memory prepared for a decimal value.

answered Oct 08 '14 at 17:50

Mark Leavenworth

61
2
12

KornShell can handle decimal values, but Bourne-like shells only do integers. – admdrew Oct 08 '14 at 17:54
Ok I figured that but how do I define a variable to be a float? – Justin Froias Oct 08 '14 at 17:56
@JustinFroias What shell are you using? – admdrew Oct 08 '14 at 17:57
@JustinFroias `tcsh` only supports integers, you'll need to use something else. [Check out this link that I put in the comments above](http://unix.stackexchange.com/questions/40786/how-to-do-integer-float-calculations-in-bash-or-other-languages-frameworks). – admdrew Oct 08 '14 at 18:21
man bc. That will give you the tools to assign floating point types. – Mark Leavenworth Oct 08 '14 at 18:27
@MarkLeavenworth Great call. Remember, though, that `bc` is *not* shell arithmetic, it's its own language. – admdrew Oct 08 '14 at 18:34
You could also create your own function and put it in a path for the shell, if you need something specific for some reason. – Mark Leavenworth Oct 08 '14 at 18:59

Script programming and significant figures

2 Answers2