(x,y) Points
[ Home ] [ Up ]

Welcome to the Teachers' Choice Software web site.
Our FREE on line mathematics 'How-To' library is open 24 hours a day. 
The ever-growing library now has 71 helpful topics, and every topic includes a free download!

Type (x,y) points as rectangular or polar points. You can also input points from a text file, or use the 'point tool' to enter points by clicking on the graph view with the mouse.

The Maths Helper Plus graph below shows some of the options for plotting (x,y) points:

Point settings

The possibilities for displaying (x,y) points are extensive: 

11 different shapes can be used for drawing the points.
Join the points with lines to make polygons.
Include error bars on the plotted points
Label each plotted point
Use the 'plot as' option to filter the 'x' and 'y' values through mathematical expressions prior to plotting. For instance, use 'logx' for 'x', and 'logy' for 'y' to create a log-log plot.
Curve Fitting

10 curve fitting models are provided. These are:

linear: y = mx
linear: y = mx + c
power: y = axb
log: y = a(logx) + b
exponential: y = aebx
polynomial, degree 4
polynomiall, degree 5
periodic: y = a sin(bx + c) + d

Regression coefficients are calculated and residuals can be tabulated and plotted.

To plot a curve for a particular model, it is as simple as clicking on the 'Plot' button.

Calculations & Stats

Various tables and useful calculated values can be obtained for a set of (x,y) points.

Click check boxes to display these:

mean 'x'
s.d. of 'x' values
variance of 'x' values
mean 'y'
s.d. of 'y' values
variance of 'y' values
'dy/dx' First derivative of points. Uses discrete algorithm, for analysis of motion. Click to plot the derivative points.
'd²y/dx²' Second derivative of points. As above, click to plot.
Enclosed area. Calculates area of polygon enclosed by points.
Fence length. Calculates length of line joining point, and perimeter of area enclosed by the points.
Custom expression option. Type a comma separated list of expressions in 'x' and 'y'. The expressions will be evaluated for each (x,y) point, and the results tabulated along with totals.

Display and tabulate components for position vectors from the origin to the points, or difference vectors between the points. Difference vectors can also be displayed as position vectors. Calculate and display resultants in a different colour.