| Pages: [1] :: one page |
| Author |
Thread Statistics | Show CCP posts - 0 post(s) |
Johnathan Walker
Caldari
Frontier Elements
   |
Posted - 2010.04.01 13:50:00 -
[1]
Good morning ladies and gents =^.^=
Any thoughts on a more effective and more accurate mineral price update for a web tool I'm working on? Code snip: http://pastebin.com/1M0zD5Gn
I'm finding that I need a lot of work on the overall tool, but the price updater seems a wee out of whack with the true market. I was hoping to improve it's functionality.
Warmly,
"The Bear" JW 
|
Catari Taga
Centre Of Attention
Rough Necks
|
Posted - 2010.04.01 15:32:00 -
[2]
Prices are going to be as good as what you upload to eve-central or your own server. In other words, you need to fix the data, not the tool. ;)
|
Johnathan Walker
Caldari
Frontier Elements
|
Posted - 2010.04.01 16:23:00 -
[3]
 Originally by: Catari Taga
Prices are going to be as good as what you upload to eve-central or your own server. In other words, you need to fix the data, not the tool. ;)
The data source isn't an issue (as that can be changed easily). I'm more looking at why I would have price discrepancies between the various mineral feeds available (Eve Central, Battleclinic, Matari Index etc).
For that matter, given that code snip, how does one CHANGE the data pull? =clueless=
Warmly,
"The Bear" JW
|
Catari Taga
Centre Of Attention
Rough Necks
|
Posted - 2010.04.01 16:34:00 -
[4]
Originally by: Johnathan Walker
Originally by: Catari Taga
Prices are going to be as good as what you upload to eve-central or your own server. In other words, you need to fix the data, not the tool. ;)
The data source isn't an issue (as that can be changed easily). I'm more looking at why I would have price discrepancies between the various mineral feeds available (Eve Central, Battleclinic, Matari Index etc).
But that's exactly what I'm saying, they have discrepancies because they do not all have the same data.
|
Johnathan Walker
Caldari
Frontier Elements
|
Posted - 2010.04.04 04:33:00 -
[5]
Originally by: Catari Taga
Originally by: Johnathan Walker
Originally by: Catari Taga
Prices are going to be as good as what you upload to eve-central or your own server. In other words, you need to fix the data, not the tool. ;)
The data source isn't an issue (as that can be changed easily). I'm more looking at why I would have price discrepancies between the various mineral feeds available (Eve Central, Battleclinic, Matari Index etc).
But that's exactly what I'm saying, they have discrepancies because they do not all have the same data.
Maybe I am not being clear.
I have the php tool, currently listing pyerite at 7isk per unit.
I have an Excel spreadsheet pulling the same feed, showing 6.95isk per unit.
Why the difference, on an identical feed?
Warmly,
"The Bear" JW
|
Dragonaire
Caldari
Corax.
New Eden Retail Federation
|
Posted - 2010.04.04 06:01:00 -
[6]
Rounding difference I would say from your example. Also might be the percussion of the math used which could be set low in php.ini it should be at least 14 digits and preferably higher.
--
Finds camping stations from the inside much easier.
Designer of Yapeal for Eve API.
|
Catari Taga
Centre Of Attention
Rough Necks
|
Posted - 2010.04.04 08:31:00 -
[7]
Edited by: Catari Taga on 04/04/2010 08:35:39
Originally by: Johnathan Walker
Maybe I am not being clear.
I have the php tool, currently listing pyerite at 7isk per unit.
I have an Excel spreadsheet pulling the same feed, showing 6.95isk per unit.
And my answer remains the same. If you look at the feed now it says 7.0 ISK for Pyerite. Your Excel tool must have pulled different data. Expose the raw data in both tools and only then can you compare.
PS: strange way of rounding you do in that php - you could better define the number of decimals you want to round to with something like round(x,2)
|
Dragonaire
Caldari
Corax.
New Eden Retail Federation
|
Posted - 2010.04.04 15:00:00 -
[8]
Not sure if you were commenting on something he said or I did but thought I'd clarify what I was talking about a bit. Also sorry for the typo meant precision 
http://php.net/manual/en/ini.core.php
I believe this setting also effect how many digits are used when variables are serialized as well. I'll agree that normally you would use round as you suggested for display but myself I avoid floating point math do to the rounding errors and use the precision math extensions like 'md' when I'm forced to work with anything that needs decimal math.
Quote:
Expose the raw data in both tools and only then can you compare.
That's the most likely cause. Even if you get your data from the same source since they are constantly getting new data if you don't have exactly the same rows of data you can of course get different results. You also need to see if one of them is in any way filtering the data so it's not using those 0.01 ISK and 1000000 ISK order you see on the market as well. I can also think of several other mathematical mistakes that one or both of them could have that can cause different results even with the same data that people commonly do. I'm not going to bore everyone with them here since you can find them in most high school first year math text books but people don't seem to remember those thing longer than they need to pass their tests anymore 
--
Finds camping stations from the inside much easier.
Designer of Yapeal for Eve API.
|
Catari Taga
Centre Of Attention
Rough Necks
|
Posted - 2010.04.04 16:26:00 -
[9]
Originally by: Dragonaire
Not sure if you were commenting on something he said or I did but thought I'd clarify what I was talking about a bit.
Sorry, since I was quoting him I thought it was clear - I was commenting on what he said, adding a different aspect. I agree with what you said. ;)
|
| |
|
| Pages: [1] :: one page |
| First page | Previous page | Next page | Last page |