Services & ResourcesWolfram ForumsMathGroup Archive

[Date Index] [Thread Index] [Author Index]

Re: Slow start to AstronomicalData[]

• To: mathgroup at smc.vnet.net
• Subject: [mg102113] Re: Slow start to AstronomicalData[]
• From: BenT <brtubb at pdmusic.org>
• Date: Thu, 30 Jul 2009 05:29:17 -0400 (EDT)
• References: <h4p3n3$j82$1@smc.vnet.net>

After the database collection is loaded and indexed (i.e. downloaded),
further access to the data such be automatic. I've confirmed that on
my on PC which is similarly configured as yours

In[106]:= $Version
DateString[]
$TimeZone

Out[106]= "7.0 for Microsoft Windows (32-bit) (January 30, 2009)"

Out[107]= "Wed 29 Jul 2009 15:04:09"

Out[108]= -5.

In[116]:= AstronomicalData["Sun", {"Altitude", {2009, 7, 30}, {23,
   00}}, TimeZone -> $TimeZone]

Out[116]= -7.34052

However when I tried to apply the {latitude, longitude} pararmeters
which can be obtained from the globle variable $GetLocation (in Fort
Walton Beach, FL), I got the following output with errors:

In[117]:= AstronomicalData["Sun", {"Altitude", {2009, 7, 30}, {23,
   00}, {$GeoLocation}}, TimeZone -> $TimeZone]

During evaluation of In[117]:= AstronomicalData::notprop: {"Altitude",
{2009, 7, 30}, {23, 0}, {{30.830000000000002, -85.74}}} is not a known
property for AstronomicalData. Use AstronomicalData["Properties"] for
a list of properties. >>

Out[117]= AstronomicalData["Sun", {"Altitude", {2009, 7, 30}, {23,
   0}, {{30.83, -85.74}}}, TimeZone -> -5.]

BTW, for convenience I suggest you devote a notebook for reference
with the output of these commands:

[define this as a Section [Alt-4]]
$Version
DateString[]
$TimeZone
$GeoLocation
?AstronomicalData

[define this as a Section [Alt-4]]
AstronomicalData[] // ColumnForm

[define this as a Section [Alt-4]]
AstronomicalData["Properties"] // ColumnForm

[define this as a Section [Alt-4]]
{* Applications *)

Ben

On Jul 29, 4:10 am, Chonny <jcon... at aerodyne.com> wrote:
> Hi,
>
>    Under Mathematica 7.0.1 I'm using:
>
>  AstronomicalData[ "Sun", {"Altitude", datetime, {lat, long}},
> TimeZone -> 0 ];
>
> to get the Sun's Az and El.  Works fine, but it takes about 50 seconds
> for "Loading Astronomical Indices...".  This is presumably because
> there is so much data in the database.
>
> Any ideas on how this could be sped up??
>
> System is WinXP Pro SP2 on a 3.2 GHz Xeon with 1.5 Gb of RAM.  Thanks.
>
> Chonny

• Follow-Ups:
  • Re: Re: Slow start to AstronomicalData[]
    • From: DrMajorBob <btreat1@austin.rr.com>