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The Datafile PD-CD 5
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DATAFILE_PDCD5.iso
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education
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2dplot
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!2D-Plot
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!Help
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1995-02-12
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2D-Plotter
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2D-Plotter is a general two-dimensional graph plotter.
____________________________________________________________________________
QUICK START
-----------
For those in a hurry to start it will be useful to know that extensive
help is available on screen at any time - just press <H> to bring up
a general Help window.
____________________________________________________________________________
Quick Example:
1. Choose Plot mode A.
2. Press F4.
3. Move mouse and click {Select} near X=1.
4. Press <T>.
5. Press <M>.
6. Press <A> and input -3,then 2 at the prompt.
7. Press <Delete>.
8. Move mouse and click {Adjust} near X=3.
9. Press <Space>.
10. Move mouse around while holding {Menu} down.
11. Click {Adjust} near X=0.
12. Press <G>
13. Press one of the other function keys F1-F12.
14. Press <Tab> to return to Main Menu.
____________________________________________________________________________
DETAILS
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2D-Plotter has four plotting modes:-
A) Cartesian functions Y=F(X)
B) Cartesian functions Y²=F(X)
C) Parametric Functions X=X(T),Y=Y(T)
D) Polar Functions R=R(L), where L=angle.
The following facilities are available:-
1) Choosing your own function.
2) Plotting a second independent function on the same graph.
3) Choosing your own scaling of the axes.
4) Real-time panning to any part of the graph.
5) Real-time zooming in/out in X or Y directions, or globally.
6) 4 plotting resolutions, from low to very high.
7) Grid lines On/Off.
The programme can also
- Show tangents (and their equations) to curves.
- Find the roots of equations (or intersection of two curves).
- Find the maxima/minima of functions.
- Calculate areas (definite integrals) between given limits.
- Calculate `Volumes of Revolution' between given limits.
- Display the coordinates of any point on the graph.
All of the above are available when plotting Cartesian functions
Y=F(X). Only a subset are available/relevant to the other
plotting modes.
Getting started
---------------
To run the programme just double-click on the !2D-Plotter icon.
You will be presented with the Plotting Modes screen.
Choosing one of the plot modes, by clicking the mouse over one of
the options A,B,C or D (or pressing <A>,<B>,<C>,<D>) will display
a graph of a function.
(This in fact is the first function F1 from one of the four sets of
functions held in the text file `Functions', within !2D-Plotter.)
Try pressing various function keys F1,...,F12.
Different example functions will be displayed.
To try a different Plotting Mode just press <Tab>. This will take
you back to the initial Plotting Mode screen. Choose a different
option <A>,<B>,<C> or <D>, or click on 'Help' for the Help screen.
Press the function keys F1,...,F12 again to display more examples.
For a brief summary of the facilities provided just press <H> at any
time - a Help screen will appear.
Facilities
----------
The various facilities come under four headings: -
(a) General
(b) Input
(c) Graph Manipulation - Keyboard
(d) Graph Manipulation - Mouse
We will consider each of these in turn:-
____________________________________________________________________________
(a) General
------------
Notation: Mouse {S} = Select, {M} = Menu, {A} = Adjust
Keyboard <X> = Press key `X' etc.
1) Plotting Mode: <Tab>
Press <Tab> to return to the initial Plotting Mode screen.
This provides four different plotting modes -
(A) Cartesian Functions Y=F(X)
(B) Cartesian Functions Y²=F(X)
(C) Parametric Functions X=X(T),Y=Y(T)
(D) Polar Functions R=R(L)
and also a `Help' box - which invokes a Help screen.
(Note: Modes (A) and (B) provide asymptotes as well.)
Choose an option by clicking the mouse on option A,B,C,D or
pressing the keys <A>,<B>,<C>,<D>.
( Note: Pressing <Space> is equivalent to choosing mode A )
The screen will display an example function from the `Library' of
functions. (In general this function will be chosen at random.)
You may now input your own function, alter the scaling etc.
2) Help: Key <H> (or click over `Help' in the Plot Modes screen)
Press <H> at any time for a summary of the facilities provided.
3) Library: Function keys F1,F2,...,F12
Pressing the function keys F1,...,F12 will display example functions.
There are 12 different ones for each plot-mode (48 in all).
This `Library' is held in the Text file "Functions" within the
!2D-Plotter Directory.
Using !Edit they can be easily changed and/or edited to suit your
own requirements. The syntax is Function, Max X, Min X, Max Y, Min Y
(on succesive lines) where the numbers Max X, Min X, Max Y, Min Y
specify the display limits of X and Y.
4) Save Screen: <S>+<Shift>
Press <S>+<Shift> to save the screen as a Mode 12 sprite.
(For subsequent printing it is probably best to press <Insert> first
to invert the colours and so save the graph with a white background.)
The screens will be saved to the directory `Graphs' already provided
within !2D-Plotter. The graphs will be saved automatically as
"Graph-1","Graph-2","Graph-3",... in sequence during each session.
After the end of a session they should then be renamed and copied to
another directory, in case they may be overwritten at the next session.
____________________________________________________________________________
(b) Input
---------
1) Function Input: <I>
Press <I> to input your own function.
You can use any of the Maths functions provided by BASIC e.g +,-,*,/,
>,<,ABS,SQR,^,SIN,COS,TAN,ASN,ACS,ATN,EXP,LN,LOG etc.
Both Plotting modes (A) and (B) require a function of X (upper case).
Plotting mode (C) requires two different functions X(T) and Y(T) of
the parameter T (upper case).
Plotting mode (D) requires a function R(L) of the angle L (upper case).
2) Second Function: <J> ( Plotting mode A only )
Press <J> to input a second function. This function is denoted G(X).
Both functions F(X),G(X) are displayed at the top-left of the screen.
The graph of the second function will be drawn in a different colour.
This facility is provided so that the points of intersection of two
functions can be easily found.
Repeated use of <J> enables different functions G(X) to be displayed
with the same `first' function F(X).
Pressing <I> and then <J> means that both F(X) and G(X) can be changed.
Press <Delete> to return to single function plotting.
3) Scaling: <Alt>
Press <Alt> to input your own scaling of the axes:-
You will be presented with a dialogue screen into which you can enter
your new values of Minimum X, Maximum X, Minimum Y, Maximum Y.
These values now become the `user' default scaling, and can always be
restored by pressing <D> (for User Default).
Note: when in Polar Mode only Minimum X and Maximum X will be required.
The Y scales will be automatically fixed to ensure a true perspective
(arbitrary scales do not make much sense in Polar mode).
The `screen' scales of the X,Y axes assumed by the programme are :-
Min X = -5, Max X = +5, Min Y = -4, Max Y = +4.
This ensures a true perspective for the 5:4 ratio of a Mode 12 screen
(although any X,Y ranges in this ratio would be equally good).
You can always return to this `screen'