Home | Download | Buy Now
Scientific Calculator			Contents | Introduction | Index

Graphing & List Window

Graphing and list manipulation is performed in a separate tool window, as shown below. Press F12 at any time to show or hide (toggle) the Graphing & List Window. Alternatively, you may select View->Graphing & Lists from the calculator's main menu.

DreamCalc Graphing & List Window (Professional Edition also shows Cashflow List)

See also: Graphing a Function, and Graphing Examples.

Note: In the Graphing & Professional Editions, the window provides a two page interface with Graphing Display and List Data page tabs. In the Scientific Edition of DreamCalc, only the List Data page is available. The Professional Edition offers an additional Cashflow List for use in financial calculations.

List Data & Statistical Modes

DreamCalc maintains two independent data lists for use in statistical calculations and data plots, namely an X-Y list and Standard Data (weighted frequency) list. The list page allows you to edit data just as you would in a spreadsheet.

Only one list is shown at any time, depending on the calculator's statistical mode. You can switch statistical mode instantly from either the Mode menu on the Graphing & List Window or the Mode menu on the main calculator interface.

Placing DreamCalc into any one of the X-Y regression modes displays the X-Y Data List, while selecting the Standard Data mode shows the SD Data List.

Sorting, Pruning & Consolidating Frequencies

From the Edit menu, you can insert and remove list rows, and sort data according to the selected column. The Prune menu option simply removes empty cells, or cells containing invalid data. If you are working with the SD list, the Consolidate Frequencies option will sort the list and combine any cells which share the same value by adding their frequencies.

Changing Chart Views

You can change chart views, without loss of data, from the Chart menu option. For example, selecting Chart->Function Grapher will show the function graphing view as displayed in the screen-shot above. You may also select from a range of available list data charts. The chart range available will depend on the current statistical mode, and charts not applicable to the current mode will be grayed out.

For example, to display a histogram, click:

Chart->Histogram

If the option is grayed out, first select the Standard Data (SD) option from the Mode menu to put the calculator into the SD mode.

X-Y Data Charts

You may plot X-Y data using any of the X-Y regression modes, and display an optional line of best-fit, as calculated for the selected regression style. X-Y data plots can be shown as a line, scatter points or X-Y bar chart, as selected from the Chart menu.

The plot below shows a Scatter Plot with a cubic regression line of best fit.

X-Y Plot with Cubic Regression

Use the Show Regression Fit option under the Chart menu to toggle the line of best-fit display on or off. In addition, X-Y plots may be displayed with logarithmic axes, or presented in parametric space. See the Axes Menu Options section, below, for more information.

Standard Data Charts

Histograms

A histogram shows the frequency distribution as a series of bars, where each bar represents an interval in the value data range. You can select the number of classes (bars) or have DreamCalc determine a suitable number using Scott's Rule by selecting "Auto" from the drop-down list.

An example histogram and cumulative variation are shown below:

Histogram Chart in Standard Data Mode

Use the Show Normal Distribution option under the Chart menu to toggle a Gaussian curve fit to the underlying data. In addition, both the Histogram and Frequency Polygon plots may show cumulative and/or relative axis variations, as selected from the Axes menu.

Frequency Polygon

The Frequency Polygon Plot is similar to a histogram, but shows the frequency distribution as a single line rather than bars. See "Histograms" above for more information.

SD Bar Chart

The SD Bar Chart displays values as a bars, in the order the they are listed, with bar widths proportional the value frequencies. A relative axis variation may be selected from the Axes menu.

Normal Q-Q Plot

Professional Edition Only. A Normal Quantile-Quantile (Q-Q) plot is a graphical technique for determining whether the data is normally distributed.

An example Q-Q Plot is shown below:

Normal Quantile-Quantile Plot

The x-axis shows the values in SD list, while the y-axis shows the expected values of a normal distribution with the same mean and standard deviation as the data. The closer the points lie to the 45° line, the closer the data resembles a normal distribution. For example, the depature from the central line in the plot above suggests that data is heavily tailed.

A relative axis variation of the Q-Q Plot may be selected from the Axes menu.

  r = f(t)

SD Axis Options

In Standard Data mode, you may select cumulative or relative options. The one or both options will be grayed out if it not applicable to the type of chart.

Cursor & Curve Tracing

Moving the cursor over the chart will cause it's current position to be displayed at the bottom left of the window in terms of axis coordinates. In addition, you will notice that as you move the cursor along a curve, a circular marker will follow the curve, indicating the y value of the curve at the current cursor x-position. The coordinates of the trace marker are displayed in the lower right of the window.

Cursor & Curve Tracing

Single clicking the mouse on the chart will lock and hold the coordinates at their current positions so that you may copy the values for later use. Where two curves are present, the trace marker will follow the one closest the cursor. Values are shown to the precision allowed by the screen size of the chart. Polar coordinates are displayed with Polar Charts.

Chart Zooming

You can perform chart zooming by simply dragging a rectangle over an area of interest with the mouse. To unzoom, click the UNZOOM label which will appear at the bottom right of the chart, or select View->Unzoom.

Exporting Charts

A chart can be saved as one of several commonly used image formats from the window's File menu. Perhaps the easiest method of export is, however, to copy it into the clipboard using the Edit menu. Two copy options are available: copy as metafile or bitmap. Metafiles are ideal for pasting into documents because they are vector based and can be resized without loss of resolution. However, there may be instances where bitmaps are preferable.

See also: Graphing a Function, and Graphing Examples.

Try DreamCalc for Free: Download Page

Home | Download | Buy Now | Support | Affiliates | About