Printing float to string with decimal rounding

ruby-talk
1

I am trying to print a float result in a string but I can get it right

I get float numbers like :
distance = 0.2568915421 , 1.2568910001, 20.3256941254 (8 decimals)

I wrote
    d = (distance.*1000).round/1000.0 # to get something like 0.257
    return "(- de 500m)" if d < 0.500
    return "( - de 1km)" if d < 1.0
    return "(env. " + d.to_s + " km)"

if d > 1.0 i print "env. 1.257 km"
I'd like to print "env. 1.2 km" shoudl I round it again ? or is there any DRY solution ?

thanks

joss

2

Kernel#format

Farrel

···

On 23/05/07, Josselin <josselin@wanadoo.fr> wrote:

I am trying to print a float result in a string but I can get it right

I get float numbers like :
distance = 0.2568915421 , 1.2568910001, 20.3256941254 (8 decimals)

I wrote
    d = (distance.*1000).round/1000.0 # to get something like 0.257
    return "(- de 500m)" if d < 0.500
    return "( - de 1km)" if d < 1.0
    return "(env. " + d.to_s + " km)"

if d > 1.0 i print "env. 1.257 km"
I'd like to print "env. 1.2 km" shoudl I round it again ? or is there
any DRY solution ?

thanks

joss

3

Is this good enough?

irb(main):010:0> "%.2f" % 1.000
=> "1.00"
irb(main):011:0> "%.2f" % 1.005
=> "1.00"
irb(main):012:0> "%.2f" % 1.006
=> "1.01"

Your values

irb(main):007:0> [0.2568915421 , 1.2568910001, 20.3256941254].map {|f| "%10.2f" % f}
=> [" 0.26", " 1.26", " 20.33"]
irb(main):008:0> [0.2568915421 , 1.2568910001, 20.3256941254].map {|f| "%.2f" % f}
=> ["0.26", "1.26", "20.33"]

Kind regards

  robert

···

On 23.05.2007 16:24, Josselin wrote:

I am trying to print a float result in a string but I can get it right

I get float numbers like :
distance = 0.2568915421 , 1.2568910001, 20.3256941254 (8 decimals)

I wrote
   d = (distance.*1000).round/1000.0 # to get something like 0.257
   return "(- de 500m)" if d < 0.500
   return "( - de 1km)" if d < 1.0
   return "(env. " + d.to_s + " km)"

if d > 1.0 i print "env. 1.257 km"
I'd like to print "env. 1.2 km" shoudl I round it again ? or is there any DRY solution ?

4

thanks a lot.. did not know about that... using too much the rails helpers...
fuunny, it's like speaking a foreign language like spanish when you know italian... similarities but also new stuff and slang ;-))

···

On 2007-05-23 16:34:50 +0200, Robert Klemme <shortcutter@googlemail.com> said:

On 23.05.2007 16:24, Josselin wrote:

I am trying to print a float result in a string but I can get it right

I get float numbers like :
distance = 0.2568915421 , 1.2568910001, 20.3256941254 (8 decimals)

I wrote
   d = (distance.*1000).round/1000.0 # to get something like 0.257
   return "(- de 500m)" if d < 0.500
   return "( - de 1km)" if d < 1.0
   return "(env. " + d.to_s + " km)"

if d > 1.0 i print "env. 1.257 km"
I'd like to print "env. 1.2 km" shoudl I round it again ? or is there any DRY solution ?

Is this good enough?

irb(main):010:0> "%.2f" % 1.000
=> "1.00"
irb(main):011:0> "%.2f" % 1.005
=> "1.00"
irb(main):012:0> "%.2f" % 1.006
=> "1.01"

Your values

irb(main):007:0> [0.2568915421 , 1.2568910001, 20.3256941254].map {|f| "%10.2f" % f}
=> [" 0.26", " 1.26", " 20.33"]
irb(main):008:0> [0.2568915421 , 1.2568910001, 20.3256941254].map {|f| "%.2f" % f}
=> ["0.26", "1.26", "20.33"]

Kind regards

  robert