convert number

convert number

[tartifola]

Hi,
I'm lost in a shell issue with no clue where to look for a solution.
I have a very long column of three digit numbers and I need to transform
each of them into a one digit number according to the following
"conversion table"

151	2
152	2
153	2
158	4
159	3
160	2
171	4
172	1
173	4

Any suggestion how to solve the problem with a shell script?
Thanks in advance

Re: convert number

[Christian Walther]

Hi,

On 19 May 2010 19:11,  <tartifola@gmail.com> wrote:
>
> Hi,
> I'm lost in a shell issue with no clue where to look for a solution.
> I have a very long column of three digit numbers and I need to transform
> each of them into a one digit number according to the following
> "conversion table"
>
> 151     2
> 152     2
> 153     2
> 158     4
> 159     3
> 160     2
> 171     4
> 172     1
> 173     4

if there is no mathematical formula for the "conversion table"
available, I would put this table in a hash, e.g. something like:

typeset -A convtable
convtable[151]=2
convtable[152]=2

etc...

If there is a value that appears very often, such as 2 in your
example, and it's not possible to parse an invalid number (such as
154-157 which doesn't appear to exist in your example), you could drop
every number that needs to be transformed to 2 and use something like:

typeset -A convtable
convtable[158]=4
convtable[159]=3
convtable[171]=4
convtable[172]=1
convtable[173]=4

The transformation would be done as

${convtable[$number]=2}

e.g.

number=158
echo ${convtable[$number]=2}
4

number=151
echo ${convtable[$number]=2}
2

HTH
Christian Walther

Re: convert number

[Bart Schaefer]

On Wed, May 19, 2010 at 11:39 AM, Christian Walther <cptsalek@gmail.com> wrote:
>
> if there is no mathematical formula for the "conversion table"
> available, I would put this table in a hash, e.g. something like:
>
> typeset -A convtable
> convtable[151]=2
> convtable[152]=2
>
> etc...

You can shortcut this:

typeset -A convtable
convtable=(151 2 152 2 153 2 158 4 159 3 160 2 171 4 172 1 173 4)

Note that you must have an even number of elements in the assignment
list, because they are taken as key value key value etc.  The
assignment will fail otherwise.

Re: convert number

[tartifola]

On Thu, 20 May 2010 07:51:09 -0700
Bart Schaefer <schaefer@brasslantern.com> wrote:

> On Wed, May 19, 2010 at 11:39 AM, Christian Walther <cptsalek@gmail.com> wrote:
> >
> > if there is no mathematical formula for the "conversion table"
> > available, I would put this table in a hash, e.g. something like:
> >
> > typeset -A convtable
> > convtable[151]=2
> > convtable[152]=2
> >
> > etc...
> 
> You can shortcut this:
> 
> typeset -A convtable
> convtable=(151 2 152 2 153 2 158 4 159 3 160 2 171 4 172 1 173 4)
> 
> Note that you must have an even number of elements in the assignment
> list, because they are taken as key value key value etc.  The
> assignment will fail otherwise.

Thanks, works perfectly.