Match part of the calculated value

ruby-talk
1

Hi,
   I have a symbol market value which changes dynamically & i have to
multiple it with static value order.

eg:
Symbol = 567.45
order = 10
Gross = symbol * order
Gross1 = 567.45 * 10 = 5674.50

In couple of seconds Symbol value might change to 567.88
So Gross2 = 567.88 * 10 = 5678.80

I wanted to compare if Gross1 and Gross2 are equal or if Gross1 has
values matching with Gross2.

Gross1 =~ /#{Gross2}/
This throws as nil for me, even if first 3 values are matching, i should
consider it was true match...how do i do that?

···

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2

Hi,

ideal one wrote in post #1066196:

Gross1 =~ /#{Gross2}/
This throws as nil for me, even if first 3 values are matching, i should
consider it was true match...

Using the =~ operator on an Integer makes no sense, because the operator
isn't really defined for Integers. It uses the dummy definition of
Object#=~, which simply returns nil and does nothing else.

But even if you convert the Integer to a String, it will get you
nowhere, because that's just not how regular expressions work. You'll
probably have to convert Gross1 to a String and go through each digit
(each_char), checking if Gross2 has the same digit (the decimal point
has to be skipped).

However, I'm not even sure how you want to compare the values:

gross1 = 414.23
gross2 = 542.14

How many matches do we have? 2? 3? Or more?

Please note: Don't use capitalized names. Ruby interprets them as
constants (which is probably not what you want).

···

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3

"Equal" does make sense for decimal numbers, but what do you mean by
"Gross1 has values matching with Gross2"? I cannot connect any math
operation with that.

Kind regards

robert

···

On Tue, Jun 26, 2012 at 9:45 PM, ideal one <lists@ruby-forum.com> wrote:

Hi,
I have a symbol market value which changes dynamically & i have to
multiple it with static value order.

eg:
Symbol = 567.45
order = 10
Gross = symbol * order
Gross1 = 567.45 * 10 = 5674.50

In couple of seconds Symbol value might change to 567.88
So Gross2 = 567.88 * 10 = 5678.80

I wanted to compare if Gross1 and Gross2 are equal or if Gross1 has
values matching with Gross2.

--
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/

4

Hi,
   Actually if you see my gross1 and gross2 values, the differences are
only at decimal level.
the first 3 numbers are in most cases matching.
So maybe i should go for 3 number/character match depending whether i am
retrieving it as a number or a string.

gross1 = 567.45 * 10
gross2 = 567.88 * 10

Thanks

Jan E. wrote in post #1066200:

···

Hi,

ideal one wrote in post #1066196:

Gross1 =~ /#{Gross2}/
This throws as nil for me, even if first 3 values are matching, i should
consider it was true match...

Using the =~ operator on an Integer makes no sense, because the operator
isn't really defined for Integers. It uses the dummy definition of
Object#=~, which simply returns nil and does nothing else.

But even if you convert the Integer to a String, it will get you
nowhere, because that's just not how regular expressions work. You'll
probably have to convert Gross1 to a String and go through each digit
(each_char), checking if Gross2 has the same digit (the decimal point
has to be skipped).

However, I'm not even sure how you want to compare the values:

gross1 = 414.23
gross2 = 542.14

How many matches do we have? 2? 3? Or more?

Please note: Don't use capitalized names. Ruby interprets them as
constants (which is probably not what you want).

--
Posted via http://www.ruby-forum.com/\.

5

I would not do any string comparison. The usual way is to define
either a max difference or a max factor between two values.

irb(main):001:0> gross1 = 567.45 * 10
=> 5674.5
irb(main):002:0> gross2 = 567.88 * 10
=> 5678.8
irb(main):003:0> (gross2 - gross1).abs
=> 4.300000000000182
irb(main):004:0> (gross2 - gross1).abs < 5
=> true
irb(main):005:0> ([gross1, gross2].max / [gross1, gross2].min)
=> 1.000757776015508
irb(main):006:0> ([gross1, gross2].max / [gross1, gross2].min) < 1.1
=> true

Since we're talking about currency values: note also there is
BigDecimal for higher precision:

irb(main):007:0> require 'bigdecimal'
=> true
irb(main):008:0> gross1 = BigDecimal('567.45')*10
=> #<BigDecimal:202be524,'0.56745E4',18(45)>
irb(main):009:0> gross2 = BigDecimal('567.88')*10
=> #<BigDecimal:202bbdec,'0.56788E4',18(45)>
irb(main):010:0> (gross2 - gross1).abs
=> #<BigDecimal:202b7990,'0.43E1',18(36)>
irb(main):011:0> (gross2 - gross1).abs.to_s
=> "0.43E1"
irb(main):012:0> (gross2 - gross1).abs < 5
=> true
irb(main):013:0> ([gross1, gross2].max / [gross1, gross2].min)
=> #<BigDecimal:202aa420,'0.1000757776 0155079742 70860869E1',36(45)>
irb(main):014:0> ([gross1, gross2].max / [gross1, gross2].min).to_s
=> "0.1000757776015507974270860869E1"
irb(main):015:0> ([gross1, gross2].max / [gross1, gross2].min) < 1.1
=> true

Cheers

robert

···

On Tue, Jun 26, 2012 at 10:47 PM, ideal one <lists@ruby-forum.com> wrote:

Hi,
Actually if you see my gross1 and gross2 values, the differences are
only at decimal level.
the first 3 numbers are in most cases matching.
So maybe i should go for 3 number/character match depending whether i am
retrieving it as a number or a string.

--
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/

6

Super Robert...this is close to what i want.

thanks

···

=> "0.43E1"
irb(main):012:0> (gross2 - gross1).abs < 5
=> true
irb(main):013:0> ([gross1, gross2].max / [gross1, gross2].min)
=> #<BigDecimal:202aa420,'0.1000757776 0155079742 70860869E1',36(45)>
irb(main):014:0> ([gross1, gross2].max / [gross1, gross2].min).to_s
=> "0.1000757776015507974270860869E1"
irb(main):015:0> ([gross1, gross2].max / [gross1, gross2].min) < 1.1
=> true

Cheers

robert

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