Re: Slow start to AstronomicalData[]
- To: mathgroup at smc.vnet.net
- Subject: [mg102181] Re: Slow start to AstronomicalData[]
- From: David Bailey <dave at removedbailey.co.uk>
- Date: Fri, 31 Jul 2009 05:58:41 -0400 (EDT)
- References: <h4p3n3$j82$1@smc.vnet.net>
Chonny 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
>
I have encountered this problem with other data collections. The problem
is that Mathematica goes to collect the data from the Wolfram server.
After it has the data stored locally, you will get a fast response if
you use it with the internet disconnected, but if it is connected, it
seems to go to check for updates. I have also seen a case in which the
internet connection was intermittent, and Mathematica produced
diagnostics at this point.
My solution was to collect the data I needed, and save it in a file.
Then the program read the file at startup, rather than calling the
relevant .....Data function.
David Bailey
http://www.dbaileyconsultancy.co.uk