Output Index


Grapher

Author : Ian Taylor

Input Types : VectorType, Curve

Date : 2 August 2000


The Graphical Displayer

The graphical displayer is a window can simultaneously display a number of data sets. Each data set can have its own line style and colour. Most triana data types can be displayed using the Grapher unit e.g. SampleSets, Spectra, Histograms, Curves etc. The specific types are converted automatically into the Triana VectorType and then Graphed.
 
 

The AutoX and AutoY check buttons enable and disable the automatic scaling of the X and Y axis. If you would like to zoom into the image then you must turn these off to stop the graph resetting to its maximum and minimum x and y values.

The Nice Nos check box specifies whether the numbers on the axis should quantise to the nearest nice values for displaying purposes. Often it is more useful to see a scale such as 0, 100, 200, 300, 400 rather than 0 99.7, 198.4 etc even though the graph may have to be re-scaled to make this possible.

The Full Size key returns the display to the maximum bounds.

The Snapshot button holds the Grapher on the current image even though other signals may be input into it. This is handy if you're use Triana as a visual feature detector. If you see what you are looking for then you can click the Snapshot to analyse the plot more closely or to save it to disk etc.

The Peak text field displays the peak frequency that is automatically detected on each iteration. This is useful for quick look purposes. Other points of interest may be seen more easily by using the marker descibed below.

Menu's

Each menu item is covered below :-

File

Edit

Options


Grapher Controls Window

The Grapher's unit Window makes it possible to change many settings to customize how the grapher display the data. The first two rows display the markers which may be added to the graph. Markers allow the user to draw vertical or horizontal lines on the graph and move them around so that exact values can be viewed. Such values are inserted into these fields.

Adding and Deleting Markers

Vertical markers can be added by double clicking at the desired position using the left mouse button. To add a horizontal marker, double click using the right mouse button. On the top of the controls window (above), there are 6 text fields. These display the precise positions of the markers and the difference between the markers. You can therefore use the markers to roughly measure, for example, signal to noise ratios etc. Markers can be moved by dragging them with the mouse and they are deleted by double clicking on them whilst holding down the control key.

The functions of the remaining widgets are described below in a chronological order:

The To Markers button zooms the display into the box created by positioning the four marker lines. The Clr Markers button clears all markers from the display.

The Zooming button brings up the Zooming-control window.

The next two choice boxes allow the following plot options (for spectral data only) :-

The next four buttons allow the user to decrease and increase the number of x and y ticks, respectively. The next three choices allow the user to set the colours and line styles for the data being displayed from each input node. There are 13 colours to choose from and 4 different line styles :-
  1. Continuous : When the points are joined.
  2. Scatter Plot : When each data points is represented by a single dot, and
  3. Impulse Plot : When a line is drawn from each point vertically to the lower horizontal axis.
  4. Bar Chart Plot : Useful for displaying Histograms. A line is drawn from each point vertically to the lower horizontal axis and horizontally to the next point.

Zooming

There are many different ways of zooming into and out of the grapher. You can use the zoom controller window for precise zooming ranges or a more intuitive way is to drag into and out of the image using the mouse. This mechanism is covered in the next section.

Using the Mouse to Zoom

There are various ways how you can use the mouse to zomm in and out of the image. These are listed below :-
  1. You can zoom to the markers by clicking the ToMkr button on the control panel.
  2. To zoom out to full size press the right mouse button.
The next functions are much more powerfull, allowing you to navigate through the image :-
  1. To zoom drag (using the left mouse button) :-
Therefore to zoom in, in both directions, drag the mouse at a 45 degree angle from top left to bottom right.
  1. To move around whilst you are zoomed into an area you press down the control key and drag (using the left or right mouse button) left to move left, right to move right, up to move up and down to move down.
  2. Perhaps the most powerfull of all is the ability to drag to the position in the display that you are interested in. This is a very usefull feature when viewing spectral information because you can literally drag to the frequency that you are interested in. To do this drag (using the right mouse button) :-

Zooming options

The Zoom option window allows you to specify precisely what area of the image you want to look at. Simply specify the north, east, south and west values editing the four self-explanatory text fields at the upper part of the window. There is also a button to go to half size, go back to full size and a radio button to select if the current zoom setting should be kept for future data inputs.

Also, there are two choice boxes at the lower part of the window which specify in which way to zoom. For example, if the user specifies the horizontal zoom to BOTH then dragging the mouse to the right will zoom into the centre part of the image. If Zoom East was selected then the right part of the image would be expanded and so on. These options should give the user enough flexibility to zoom in and out in the desired way for their particular type of data.