Graph Notes - Chart Properties

The Chart Properties pop-up window provides a user interface that can be reused for many different graphs. It allows the user to Note that all the changes are live - there is no Apply button. As a result, when editing some fields, illegal values may be entered. Internal error checking will take care of most of this, but if a warning is produced, just fix the problem and continue. Copy (Ctrl-Ins) and paste (Shift-Ins) will solve most problems typing numbers.

One typical scenario might be to select 2 of the available series and to associate one with each of the two available y-axes - left and right. In this case, the user would enter the appropriate axes titles and a new (and appropriate) graph title.

Once the desired scaling adjustments are made, the user would create a jpeg image of the graph as a final product. An *.ini (configuration) file might be created so that it would be easier to recall the settings that were used (assuming that the option is available).

Series | General | Axes


Series

Each series can be associated with either the top or bottom horizontal axes (simplifies time shifting several series at the same time) and with the left or right vertical axes.

Show Values displays the y-value of each point.

Show Markers places a box at each y-value.

When scaling is enabled, the 3 sliders allow the user to scale and position each series as appropriate. This provides the opportunity to compare data with different ranges (minimum and maximum values) and offsets (distance from the x-axis or y-axis). The associated max and min fields allow the user to specify the range of the associated sliders. By default, the sliders only provide integer values. For the 2 position controls, that is adequate. However, for the scaling control, a finer adjustment is needed. The Number of decimal places selection allows the Scale scroll bar to produce values less than one, allowing the range (vertical size) of a series to be reduced.

Remember, all 3 sliders are live - the graph is dynamically updated.


General

This tab allows the user to edit the graph title, including the font color, font size, and related properties.

This tab also allows the user to save an image of the graph to a file, or to copy the image to the clipboard. The options allow the user to select either the entire form, or just the graph. Two different filetypes are provided - bmp and jpeg. The jpeg's are saved with quality = 90 (out of 100).

If you want a different graph size, resize the application before saving.

If the application enables it, there will be buttons to load and save *.ini (configuration) files. If you load a file which is not appropriate for this specific plot, the results are unpredictable.


Axes

This tab allows the user to edit the title of each axis, including the font color, font size, and related properties.

Normally, the axes are automatically scaled. Unchecking the Automatic option allows the user to manually set whatever values are appropriate. (The default values are those automatically set.) The application requires that the minimum value must be smaller than the maximum. When the user enters values that violate this, both values turn red until the problem is corrected.

The Log option displays a logarithmic scale. Note that the minimum value must not be zero or negative.

Invert swaps the direction the axis is drawn - for the vertical axes, the minimum values will be at the top - for the horizontal axes, at the right.

When 2 horizontal or 2 vertical axes are used, the tick marks normally do not be align and having both sets of grids enabled is just a mess. The Display Grid option allows the user to select which sets of grid lines to use.


Author: Robert Clemenzi
URL: http:// mc-computing.com / Science_Facts / Graph_Notes / ChartProperties.html