I want to evaluate the following interactively:
28977682.9/x
It is the Weins’s Displacement Law Equation
How do I write a Ruby P. to evaluate it
There is a equivalent program on Wolfram Alpha
How do I write a Ruby P. to evaluate it
You just did. 
I want to input the variable, which changes, from the console and
evaluate multiple examples without entering the constant multiple times.
On 2013-06-23, at 5:03 PM, Mike S. [email protected] wrote:
#!/usr/bin/env ruby
require ‘rubygems’
require ‘highline/import’CONST = 28977682.9
begin
loop do
num = ask("Enter number: ", Float)
puts CONST * num
Oops, that * should be a /.
–
Mike S. [email protected]
http://www.stok.ca/~mike/
The “`Stok’ disclaimers” apply.
On 2013-06-23, at 2:51 PM, “Michael P F.” [email protected] wrote:
I want to input the variable, which changes, from the console and
evaluate multiple examples without entering the constant multiple times.–
Posted via http://www.ruby-forum.com/.
Do yo mean something like this (which uses the highline gem to prompt
for input and coerce it to the right type):
#!/usr/bin/env ruby
require ‘rubygems’
require ‘highline/import’
CONST = 28977682.9
begin
loop do
num = ask("Enter number: ", Float)
puts CONST * num
end
rescue EOFError
puts “Bye!”
end
END
Hope this helps,
Mike
–
Mike S. [email protected]
http://www.stok.ca/~mike/
The “`Stok’ disclaimers” apply.
I get the following error message in Ubuntu Terminal
michael@michael-desktop:~/Desktop$ ruby<weins.txt
/usr/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in require': cannot load such file -- highline/import (LoadError) from /usr/lib/ruby/1.9.1/rubygems/custom_require.rb:36:inrequire’
from -:4:in `’
michael@michael-desktop:~/Desktop$ ^C
michael@michael-desktop:~/Desktop$
Thanks for the effort, anyway
Mike Finerty
It runs but doesn’t pause for a input. Here is the Terminal output
michael@michael-desktop:~/Desktop$ ruby<weins.txt
Enter number: enter a number please.
Enter number: Bye!
michael@michael-desktop:~/Desktop$
MikeOn 2013-06-23, at 5:28 PM, “Michael P F.” [email protected] wrote:
Thanks for the effort, anyway
Mike Finerty
–
Posted via http://www.ruby-forum.com/.
That means you don’t have the highline gem installed, it is a little
more verbose if you don’t use that, we have to check for the input being
exhausted and for input which can’t be turned into a Float so maybe:
#!/usr/bin/env ruby
CONST = 28977682.9
catch (:done) do
loop do
print "Enter number: "
throw :done unless response = gets
if num = Float(response) rescue nil
puts CONST / num
else
puts "enter a number please."
end
end
end
puts “Bye!”
END
Hope this helps,
Mike
–
Mike S. [email protected]
http://www.stok.ca/~mike/
The “`Stok’ disclaimers” apply.
IT WORKS! Thank you. I will give you credit.
MikeOn 2013-06-23, at 6:04 PM, “Michael P F.” [email protected] wrote:
It runs but doesn’t pause for a input. Here is the Terminal output
michael@michael-desktop:~/Desktop$ ruby<weins.txt
Enter number: enter a number please.
Enter number: Bye!
michael@michael-desktop:~/Desktop$Mike
If you saved the program in weins.txt then try
ruby wiens.txt
When you run you run ruby <weins.txt then the contents of weins.txt are
used as the standard input stream which ruby consumes and executes, then
hits the end of file.
On my laptop:
ratdog:tmp mike$ cat try.rb
#!/usr/bin/env ruby
CONST = 28977682.9
catch (:done) do
loop do
print "Enter number: "
throw :done unless response = gets
if num = Float(response) rescue nil
puts CONST / num
else
puts "enter a number please."
end
end
end
puts “Bye!”
END
ratdog:tmp mike$ ruby try.rb
Enter number: 1
28977682.9
Enter number: 2
14488841.45
Enter number: 2.3
12598992.565217393
Enter number: banana
enter a number please.
Enter number: Bye!
(I hit Ctrl-D at the last prompt)
Hope this helps,
Mike
–
Mike S. [email protected]
http://www.stok.ca/~mike/
The “`Stok’ disclaimers” apply.