NAME
Finance::Shares::multiline_mean - Calculate the average of a number of lines
SYNOPSIS
Two examples of how to specify a multiline mean, one showing the minimum required and the other illustrating all the possible fields.
use Finance::Shares::Model;
use Finance::Shares::multiline_mean;
my @spec = (
...
lines => [
...
minimal => {
function => 'multiline_mean',
lines => '*///line1',
},
full = {
function => 'multiline_mean',
graph => 'Stock Prices',
gtype => 'price',
lines => [qw(line1 line2 line3)],
key => 'average of 3 lines',
style => { ... },
shown => 1,
order => -99,
},
...
],
samples => [
...
one => {
lines => ['full', 'minimal'],
...
}
],
);
my $fsm = new Finance::Shares::Model( @spec );
$fsm->build();DESCRIPTION
This module calculates the average of several lines. It is probably most useful when averaging lines created by the same function on several different samples.
To be any use, there must be a Finance::Shares::Model specification lines entry that has a function field declaring the module's name. Then the entry's tag must be used by a sample in some way. This may be either directly in a line field, or by referring to it within a test.
The other main fields are lines, gtype or graph.
OPTIONS
function
Required. Must be multiline_mean.
graph
If present, this should be a tag declared as a charts resource. It identifies a particular graph within a chart page. A gtype is implied. (No default)
gtype
Required, unless graph is given. This specifies the type of graph the function lines should appear on. It should be one of price, volume, analysis or level. (Default: price)
lines
This array ref should list the names (tags or fully qualified) of the lines to be averaged. For convenience, a wildcard, '*' form can be used to specify 'all the pages but this one'. So to find the average of all 10-day moving averages on a list of stocks:
lines => [
'10day' => {
function => 'moving_average',
period => 10,
},
'mean' => {
function => 'multiline_mean',
lines => '*///10day',
},
],
samples => [
shares => {
stock => [qw(HBOS.L LLOY.L HSBC.L)],
line => '10day',
},
summary => {
stock => '',
line => 'mean',
},
],This will produce a 4-page file with the last page showing the average of the others.
key
Most functions generate suitable (if lengthy) entries. This provides the opportunity to identify the line in the Key panel, next to the style.
order
The entries on the graph are sorted according to this value, which defaults to the order required for calculation. A large integer will bring the line to the front and a negative number will put it behind all the rest.
Examples
- -1
-
The line goes behind the data.
- 0.5
-
In front of the data, but only just.
- 999
-
Probably the top line.
shown
1 for the line to be shown, 0 hides it. (Default: 1)
style
This is normally a hash ref defining the data's appearance. See PostScript::Graph::Style for full details, or "Lines" in Finance::Shares::Model for an example.
BUGS
Please let me know when you suspect something isn't right. A short script working from a CSV file demonstrating the problem would be very helpful.
AUTHOR
Chris Willmot, chris@willmot.org.uk
LICENCE
Copyright (c) 2002-2003 Christopher P Willmot
This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. A copy can be found at http://www.gnu.org/copyleft/gpl.html
SEE ALSO
Finance::Shares::Overview provides an introduction to the suite, and fsmodel is the principal script.
Modules involved in processing the model include Finance::Shares::Model, Finance::Shares::MySQL, Finance::Shares::Chart. Chart and file details may be found in PostScript::File, PostScript::Graph::Paper, PostScript::Graph::Key, PostScript::Graph::Style.
All functions are invoked from their own modules, all with lower-case names such as Finance::Shares::moving_average. The nitty-gritty on how to write each line specification are found there.
The quote data is stored in a Finance::Shares::data object. For information on writing additional line functions see Finance::Share::Function and Finance::Share::Line. Also, Finance::Share::test covers writing your own tests.
1 POD Error
The following errors were encountered while parsing the POD:
- Around line 190:
Expected text after =item, not a number