Charts

The following chart types are used in EMarketOffer:

• Supply Curve Graph
• Offer Graphs
• Demand Histograms
• General Purpose Charts

The Supply Curve Graph

Access

The Supply Curve option is under the Supply and Demand item on the Edit menu of the Main Window and is available for all Data Source types.

Purpose

The Supply Curve Graph displays the Offer Stack for the Current Data Set (excluding the Powerflow Case Data Source). The Graph appears in its own window and is updated whenever the Current Data Set changes.

Features

Feature	Purpose
Title Bar	Shows Current Data Source and Current Period displayed in the graph
Price Axis	Non-Linear scale of Offer price
Quantity Axis	Represents total offered quantity (MW) in the Current Period
Demand Line	System Demand for the Current Period
Supply Curve	A line joining the price points in the Supply stack
Supply Roll Over	A mouse-activated feature that shows details about the Unit offering capacity at that (vertical) point on the Supply Curve. NOTE: It should NOT be assumed that a Unit belongs to a marginal Generation Station if an offer band is not fully dispatched
Dispatched Shading	Provides a vertical shaded band at right angles to the Supply Curve at every point along where quantity offered was actually dispatched. This means that: Generation that was expected to be dispatched based on price but was not, shows as vertical white bands to the left of the Demand Line Generation that was not expected to be dispatched on price but was, shows as vertical green bands to the right of the Demand Line
Options Link	Open the Supply Curve Options Window to customise the appearance of the Supply Curve Graph

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NOTE: The Supply Curve Graph Window is sizeable. The chart area expands and compresses to fill the available space.

The Supply Curve Options Window

Access

The Options Link on the Supply Curve Graph.

Purpose

To customise the appearance of the Supply Curve Graph

Feature	Purpose
Supply Colour	Uses the Windows Colour Picker to select a colour for the Supply Curve line
Demand Colour	To select a colour for the Demand line
Generation Colour	To select a colour for the Generation
Show Generation Fill	On/Off Toggle for the display of the dispatched generation shading

The Offers Graph

Access

The Offers Graph Option under the Supply and Demand item on the Edit menu of the Main Window and is available for the Forecast and Market (when available) Data Source types.

Purpose

To display Offers data by Generation Station or by Price, using configurable colour coding to identify Price bands and Generation Stations.

Graph Display Types

Graph Display	Default Date Range	Access
A selected date range in a Market Data Source	Current day Periods 1 to 48	Main Window Menu Bar Edit > Supply and Demand > Offers Graph
A selected date range in a Forecast Data Source	Current day Periods 1 (or first forecast period if > 1) to 48 (or last forecast period if < 48)	Main Window Menu Bar Edit > Supply and Demand > Offers Graph
A selected day (or days) in a weekly Offer profile in a Forecast Definition	Current day Periods 1 to 48	Forecast Definition Window Edit > Offers Graph

Features

Feature	Purpose
Title Bar	Displays the Chart's Data Source
Menu Bar	Provides access to the chart's functions
Date Range Picker	Sets the date range displayed in the chart
Chart Area	Displays Offers as a shaded column for each Trading Period coloured by user-defined Offer Price bands Graphs system Demand as a single line

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NOTE: The Offers Graph Window is sizable. The chart area expands and compresses to fill the available space.

Offers Graph Concepts

Display Modes

The Chart Area has two modes of display:

1. Offers by Price: which segments the entire Offer stack into user-defined Price bands by Trading Period
2. Offers by Generation Station: which segments the entire Offer stack by individual Generation Unit by Trading Period

Display Elements

The following elements appear in the Chart Area display:

Element	Purpose
Quantity Axis	Measures total offered quantity in MW
Time Axis	Demarcates the Chart date range using Date and Period markers
Graph Area	A continuous area of single colour on the Chart indicating either: a band of offered quantity falling within a user-defined price range (Offers by Price); or a band of quantity offered by a single Generation Unit (Offers by Generator)
Guideline	A line of user-defined colour joining the points across all displayed periods above which Offer Price exceeds the Price associated with the line
Load Line	A dark grey line joining the points of system Demand across all displayed Periods
Load Region	Area under the Load Line (can be shaded with semi-transparent pale grey)
Chart Rollover	A mouse-activated feature causing a roll-over panel to appear containing information associated with the underlying graph point
Legend	Displays the colours used in the chart

The Offers Graph allows you to customise the following display items:

Item	Editor
Price Band Value and Colour	Change Graph Colour Window through the Price Colouring option from the Colouring Menu
Displayed Generation Stations	Change Graph Colour Window though the Generation Colouring option from the Colouring Menu
Guideline value and colour	Change Graph Colour Window though the Guideline Colouring option from the Colouring Menu
Load Line, Load Zone and Guideline visibility	Options Menu
Displayed Company and its colour	The Company Colouring Window though the Company Colouring option from the Colouring Menu