Graphing Examples

Graphing Sine & Cosine

This screenshot shows the Chart & List Window being used to generate sine and cosine function plots. An integral calculation, between the range 2 to 5, is also shown for plot A.

Sine and Cosine Functions

These plots can be generated using the input parameters below. See Graphing a Function for more information.

Input Plot A: sin(x)
Plot B: cos(x)
Range 0; 2pi
Angle Mode Radians
No. Points 1000
Notes Click the Calc button and then select Integral of Plot A to perform the integral calculation.

Square Wave with Random Noise

Square Wave with Noise

Input SIGN(sin(x)) + 0.2 * Ran - 0.1
Range 0; 3
Angle Mode Cycles
No. Points 100
Notes The SIGN function converts sine into a square wave, while Ran adds "noise". The noise will change each time you plot the function.

Graphing an Asymptote

Asymptote

Input 1 / x
Range -10; +10
Angle Mode N/A
Interval 0.5
Notes Use "Interval", not "No. Points" so as to create a discontinuity at x = 0 (i.e. 1 / 0 -> INFINITY).

Equation of Time

The "equation of time" approximates the difference between the apparent time and mean time (i.e. between solar noon and noon on the clock) throughout the year. The difference is due to a combination of the obliquity of the Earth's rotation axis and the eccentricity of its orbit.

Equation of Time

Input 9.87 * sin (2 * 360 * (x - 81) / 364) - 7.53 * cos (360 * (x - 81) / 364) - 1.5 * sin (360 * (x - 81) / 364)
Range 1; 365
Angle Mode Degrees
No. Points 100
Notes  

Creating a Polar Plot

Below is the Polar Rose—a famous polar plot that looks like a petalled flower.

Polar Plot

Input 8 * sin(2.5t)
Range 1; 4pi
Angle Mode Radians
No. Points 200
Notes Enter the above equation and select: Axes->Polar Plot.

Regression Analysis

Below, a scatter plot of X-Y data with a line of best fit, as determined by cubic regression analysis.

Cubic Regression

Mode Cubic Regression (X-Y)
Chart X-Y Scatter Plot
Select: Chart->X-Y Data Charts->Show Regression Fit to show best fit.
Notes Import File: sample_xy_data.txt

Histograms

Below is a histogram generated using data in the DreamCalc SD Data List. The second chart shows a cumulative plot of the same data. The actual data values used to generate these plots can be found in the notes below.

Histogram

Cumulative Histogram

Mode Statistical Data (SD)
Chart Histogram
Select: Axes->Cumulative for the cumulative variation.
Notes Import File: sample_histogram_data.txt

Normal Q-Q Plots

Professional Edition Only. A Normal Quantile-Quantile Plot generated using data in the DreamCalc SD Data List. The actual data values used to generate this plot can be found in the notes below.

Q-Q Plot

Mode Statistical Data (SD)
Chart Normal Q-Q Plot (Professional Edition Only)
Notes Import File: sample_qq_data.txt

Cashflow Chart

Professional Edition Only. The chart below shows cash amounts held in the cashflow list—a separate data list used in the financial calculations supported by the Professional Edition of DreamCalc.

Cashflow Chart

Mode Any - cashflow data is independent of other lists.
Chart Cashflow
Cashflow -2000, 3232, 7000, 9535, 13500, 21543, 12545, 18232, 11033, 7543, 5075

See also: Chart & List Window, and Graphing a Function