[mg27156] String to Number

[Ken Levasseur-UML]

Steffen:

Here is one way to do it. It assumes the presence of a semicolon to
identify the two parts.

tstrings = {"06:42", "12:30", "1:22", "13:45"};
In[57]:=
convert[t_String] := (t //
Characters) /. {{a__, ":",
b__} :> (ToExpression[StringJoin[#]] & /@ {{a}, {b}})}
In[58]:=
convert /@ tstrings
Out[58]=
{{6, 42}, {12, 30}, {1, 22}, {13, 45}}

Ken Levasseur
Math Sciences
UMass Lowell

stef...@server2.fo.FH-Koeln.DE wrote:

> Hi
>
> I read a time from a file (this format 06:42) as a string.
>
> I would like to convert this string into to numbers (6 and 42).
>
> any suggestions?
>
> Thanks
>
> Steffen
>
>
> Dipl.-Ing. Steffen Zozgornik
>
> Institut fur Licht- und Bautechnik
> an der Fachhochschule Koeln
> Gremberger Strasse 151 a
> D - 51105 Koeln
>
> Tel.: +49 - 221 - 83 10 95
> Fax.: +49 - 221 - 83 55 13

[Helge Andersson]

stef...@server2.fo.FH-Koeln.DE wrote:

> Hi
>
> I read a time from a file (this format 06:42) as a string.
>
> I would like to convert this string into to numbers (6 and 42).
>
> any suggestions?
>
> Thanks
>
> Steffen
>
>
> Dipl.-Ing. Steffen Zozgornik
>
> Institut fur Licht- und Bautechnik
> an der Fachhochschule Koeln
> Gremberger Strasse 151 a
> D - 51105 Koeln
>
> Tel.: +49 - 221 - 83 10 95
> Fax.: +49 - 221 - 83 55 13

Hello Steffen,
Here are some solutions:

In[11]:=
str = {"06:42", "07:56", "11:23"};
pos = {2, {4, 5}};
li = Flatten[Table[{i, #} & /@ {pos[[1]], pos[[2]]}, {i, 1,
Length[str]}], 1];

In[34]:=
newvars1 = Partition[ToExpression[StringTake[str[[#1]], #2]] & @@@ li,
2];

newvars2 =
Table[#1[#2[#3, pos[[j]]]], {j, 1, 2}] &[ToExpression, StringTake,
str[[#]]] & /@ {1, 2, 3};

newvars3 =
Partition[
Map[StringTake, Sequence @@ {str[[#1]], #2} &] @@@ li //
ToExpression,
2];

In[37]:=
Scan[Print, {li, newvars1, newvars2, newvars3}]

{{1, 2}, {1, {4, 5}}, {2, 2}, {2, {4, 5}}, {3, 2}, {3, {4, 5}}}

{{6, 42}, {7, 56}, {11, 23}}

{{6, 42}, {7, 56}, {11, 23}}

{{6, 42}, {7, 56}, {11, 23}}

Helge Andersson
Environmental Inorganic Chemistry
Chalmers
SE-412 96 Göteborg

Tel. 031-772 8072
Fax 031-772 2853

[David Park]

Steffen,

If the string is always in the form "mm:ss" you could do this:

str = "06:42"
{minutes, seconds} = ToExpression /@ {StringTake[str, 2],
StringTake[str, -2]}
{6, 42}

If the minutes could go beyond 99 and the seconds could have a decimal
point, and there is always one and only one colon, then you could use this.

toMinutesSeconds[str_] :=
With[{poscolon = StringPosition[str, ":"][[1,1]]},
ToExpression /@ {StringTake[str, poscolon - 1],
StringDrop[str, poscolon]}]

str2 = "124:23.456"

{minutes, seconds} = toMinutesSeconds[str2]
{124, 23.456}

David Park
dj...@earthlink.net
http://home.earthlink.net/~djmp/

[Tomas Garza]

I presume you want to delete the zero both in the hours and in the minutes,
when they are less than 10, right? Suppose, then, you read the string in the
format hh:mm.
The following function will do what you want:

In[1]:=
makeNumbers[x_String] :=
ToExpression[{If[StringTake[x, 1] == "0", StringTake[x, {2}],
StringTake[x, 2]],
If[StringTake[x, 3] == "0", StringTake[x, {-2}], StringTake[x, -2]]}]

In[2]:=
makeNumbers["06:42"]
Out[2]=
{6, 42}
In[3]:=
makeNumbers["12:28"]
Out[3]=
{12, 28}
In[4]:=
makeNumbers["12:03"]
Out[4]=
{12, 3}

Tomas Garza
Mexico City

[stef...@server2.fo.fh-koeln.de]

Dear Tomas,

thank You for Your function, but the zeros are "deleted"
automatically after conversion into a number.

Steffen

> Date: Thu, 08 Feb 2001 12:31:51 -0600
> From: Tomas Garza <tgar...@prodigy.net.mx>
> Subject: Re: [mg27156] String to Number > To: stef...@server2.fo.FH-Koeln.DE
> Cc: math...@smc.vnet.net

Dipl.-Ing. Steffen Zozgornik

Institut für Licht- und Bautechnik
an der Fachhochschule Köln
Gremberger Straße 151 a
D - 51105 Köln

[Paul Lutus]

<stef...@server2.fo.FH-Koeln.DE> wrote in message
news:yzij6.3290$Rl5....@ralph.vnet.net...

> Dear Tomas,
>
> thank You for Your function, but the zeros are "deleted"
> automatically after conversion into a number.

Yes, of course they are. That is because when you perform this example --

> > makeNumbers["06:42"]

You get this:

> > Out[2]=
> > {6, 42}

There is no number "06." Numbers don't have leading zeros.

Maybe we are not understanding your question as you intend it.

In your original post, you asked this:

> > > I read a time from a file (this format 06:42) as a string.
> > >
> > > I would like to convert this string into to numbers (6 and 42).

The reply by Mr. Garza does this.

--
Paul Lutus
www.arachnoid.com