Hi, I am a ruby newbie. I want to write a program which will scan a input file, change every digital number into 4 bits len's binary number. For example, for input.txt as 903 1047 I will get a new file as 100100000011 0001000001000111 Would anyboby kindly help to tell me how to do this?

on 2007-03-26 03:26

on 2007-03-26 03:38

On 3/26/07, Ak 756 <macro.peng@gmail.com> wrote: > 100100000011 > 0001000001000111 > > Would anyboby kindly help to tell me how to do this? I don't know what a "4 bits len's binary number" is. But here's how you convert decimal to binary in Ruby: irb(main):004:0> 903.to_s(2) => "1110000111" irb(main):005:0> 1+2+4+128+256+512 => 903 Hope that helps, -Harold

on 2007-03-26 04:18

I assume that by "4 bits len binary number" he means that he wants the binary number to be a multiple of 4 characters long. So the binary number would have "0" prepended to it if the size wasn't divisible by 4. Here is an overly verbose way to convert the num to the binary number string. irb(main):001:0> def int_to_binary(num) irb(main):002:1> binary_num = num.to_s(2) irb(main):003:1> if ((binary_num.size % 4) > 0) irb(main):004:2> binary_num = ('0' * (4 - (binary_num.size % 4))) + binary_num irb(main):005:2> end irb(main):006:1> binary_num irb(main):007:1> end => nil irb(main):008:0> int_to_binary(903) => "001110000111" irb(main):009:0> int_to_binary(15) => "1111" irb(main):010:0> int_to_binary(16) => "00010000" irb(main):011:0>

on 2007-03-26 05:32

Mike Moore wrote: > irb(main):008:0> int_to_binary(903) > => "001110000111" Hi ,thanks for advise. I want my function to give output 100100000011 for input 903. Where '1001','0000','0011' is the binary value for 9,0,3 Is there efficient way to do this?

on 2007-03-26 06:04

On 26 Mar 2007, at 12:32, Ak 756 wrote: > -- > Posted via http://www.ruby-forum.com/. > 903.to_s.split(//).map{|n| sprintf("%04d",n.to_i.to_s(2))}.join Alex Gutteridge Bioinformatics Center Kyoto University

on 2007-03-26 06:05

```
On Mar 26, 1:32 pm, Ak 756 <macro.p...@gmail.com> wrote:
> Posted viahttp://www.ruby-forum.com/.
Maybe this one is goon for you?
903.to_s.split(//).map{|x| tmp=x.to_i.to_s(2); "0"*(4-tmp.length)
+tmp}.join
```

on 2007-03-26 06:07

Ak 756 wrote: > Mike Moore wrote: > >> irb(main):008:0> int_to_binary(903) >> => "001110000111" > > Hi ,thanks for advise. > I want my function to give output 100100000011 for input 903. Where > '1001','0000','0011' is the binary value for 9,0,3 > Is there efficient way to do this? "903".split("").map{|s| "%04b" % s.to_i}.join => "100100000011"

on 2007-03-26 06:07

On 3/26/07, Ak 756 <macro.peng@gmail.com> wrote: > Mike Moore wrote: > > > irb(main):008:0> int_to_binary(903) > > => "001110000111" > > Hi ,thanks for advise. > I want my function to give output 100100000011 for input 903. Where > '1001','0000','0011' is the binary value for 9,0,3 > Is there efficient way to do this? > I don't know about efficent, but you could start with something like this and see if it's performant enough: irb(main):002:0> 903.to_s.split("").each {|digit| p digit.to_i.to_s(2)} "1001" "0" "11" Meh, actually, I bet someone else can do better than that, but I'm at work right now. (: -Harold

on 2007-03-26 06:11

On 3/25/07, Ak 756 <macro.peng@gmail.com> wrote: > -- > Posted via http://www.ruby-forum.com/. > > irb(main):001:0> "903".split(//).map { |c| "%04b" % c } => ["1001", "0000", "0011"] irb(main):002:0> "903".split(//).map { |c| "%04b" % c }.join => "100100000011" irb(main):003:0> "903".split(//).map { |c| "%04b" % c }.join(' ') => "1001 0000 0011" irb(main):004:0> Something like that I would work,another approach would be to use pack with an H to then process the resulting string in bits. pth

on 2007-03-26 06:55

On Mar 25, 10:06 pm, Joel VanderWerf <v...@path.berkeley.edu> wrote: > Ak 756 wrote: > > I want my function to give output 100100000011 for input 903. Where > > '1001','0000','0011' is the binary value for 9,0,3 > > Is there efficient way to do this? > > "903".split("").map{|s| "%04b" % s.to_i}.join > => "100100000011" No need to call to_i on the digit strings: irb(main):002:0> 903.to_s.split('').map{|n| "%04b" % n }.to_s => "100100000011"

on 2007-03-26 07:00

Gavin Kistner wrote: > On Mar 25, 10:06 pm, Joel VanderWerf <v...@path.berkeley.edu> wrote: >> Ak 756 wrote: >> > I want my function to give output 100100000011 for input 903. Where >> > '1001','0000','0011' is the binary value for 9,0,3 >> > Is there efficient way to do this? >> >> "903".split("").map{|s| "%04b" % s.to_i}.join >> => "100100000011" > > No need to call to_i on the digit strings: > > irb(main):002:0> 903.to_s.split('').map{|n| "%04b" % n }.to_s > => "100100000011" Woo.., that's really what's I want. Thanks you guys-:)

on 2007-03-26 07:04

Phrogz wrote: > irb(main):002:0> 903.to_s.split('').map{|n| "%04b" % n }.to_s > => "100100000011" Had no idea that would work, but now it seems obvious.... Apparently #Integer is being called by #% when the format char is 'b', because it works correctly with different bases: "%04b" % "16" => "10000" "%04b" % "0x10" => "10000" "%04b" % "0b10000" => "10000"

on 2007-03-26 08:54

On Mon, Mar 26, 2007 at 10:26:35AM +0900, Ak 756 wrote: > For example, for input.txt as > > 903 > 1047 > > I will get a new file as > > 100100000011 > 0001000001000111 > >> 0x903.to_s(2) => "100100000011" >> 0x1047.to_s(2) => "1000001000111" And so it was: puts IO.read('input.txt').map { |x| x.to_i(16).to_s(2) }.join _why

on 2007-03-26 14:17

On 3/26/07, _why <why@ruby-lang.org> wrote: > > > _why > > >> format("%0#{"193".length*4}b", 0x193) => "000110010011" to get leading zeros. And so , the following puts IO.read('input.txt').map { |x| format("%0#{x.chomp.length*4}b",x.to_i(16)) }.join("\n") Prasad

on 2007-03-27 17:59

On 3/25/07, Ak 756 <macro.peng@gmail.com> wrote: > Mike Moore wrote: > > > irb(main):008:0> int_to_binary(903) > > => "001110000111" > > Hi ,thanks for advise. > I want my function to give output 100100000011 for input 903. Where > '1001','0000','0011' is the binary value for 9,0,3 > Is there efficient way to do this? Just for the record, that is commonly called BCD (for Binary Coded Decimal). -- Rick DeNatale My blog on Ruby http://talklikeaduck.denhaven2.com/