home *** CD-ROM | disk | FTP | other *** search
- Help text for Algebra Editor Graphics Mode Controls
-
- KEY What is Does KEY These keys are 3D ONLY
- ------ ------------- --- ---------------------
- esc leave graphics enter toggle (3D*) camera mode
- 'g' toggle 2D and 3D mode ins del camera distance to origin
- home more points (smoother) 3D* move camera forward
- end fewer points ctrl-arrows move function grid
- 'a' toggle polar mode ctrl-ins,del size function grid
- 'V' exchange variables ctrl-pgup,dn size z axis function grid
- 'd' reset default options 'c' color by height or slope
- '1'...'9' add step to one var 'z' spread the colors over the
- 'q'...'o' subtract step var range of the function
- '0' 'p' change step 'f' fill mode, 5-way toggle
- ins del zoom in, out 'x' use 256 color/gray palette
- pgup pgdn 2D scale y axis '-' '=' rotate 256 color palette
- 3D scale y axis ',' '.' change camera focal length
- 3D* rotate camera z F5 F6 adjust brightness of slope
- arrows 2D move viewport
- 3D move camera around origin
- 3D* rotate camera x,y
-
- Warning! A common mistake is to accidentally leave a formula in the KEY and
- the graph is all messed up. Solution: clear the key (press ENTER) before
- using graph mode.
-
- The 3D camera usually always looks at the origin. The Enter key is a toggle
- to allow direct control of the camera using the 3D* keys.
-
- Both 2D and 3D plot the pick on the y axis (vertical). If the key is
- specified, it is plotted on the x axis (horizontal). Otherwise, the first
- variable found in the pick is used for the x axis. Press 'V' (shift-V) to
- change the variables used for the x and y axes.
-
- The number keys and the top row of letters (q,w,e,r,t,y,u,i,o,p) are use to
- adjust the rest of the variables found in the function. For instance, when
- you plot a^2+b*c, the "a" variable is used as the x axis (in 3D mode, b is the
- z axis). If you want to see how it looks with different values of c you can
- change it by pressing '2' to increase and 'w' to decrease. In 2D mode, you
- could use '1' and 'q' to adjust b. In 3D mode, '1' and 'q' do nothing. The
- "step" or amount of adjustment is changed with '0' and 'p'.
-
- In polar coordinates mode, the x axis becomes the angle (theta) and the y axis
- becomes the radius. In 2D the domain of x still depends on the viewport size.
- In 3D, the first independent variable determines the angle of latitude
- [-pi/2, pi/2] and the second independent variable determines the angle of
- longitude [-pi, pi]. For a 3D example, pick=2 is a sphere of radius 2, and
- cos(x) is a donut (with no hole).
-
- By pressing 'c' twice you can color the function by its slope. If you combine
- this with gray scale coloring you can produce a shading effect. For VGA 256
- users, press 'dfxxcc' to see a shaded graph. The ?r option controls the
- direction of the "light source". Always give the light source a positive y.
-
- Known bugs:
-
- * The FILLED MODE uses filled polygons to paint the 3D graph. It it does not
- do depth sorting, so from some perspectives the picture looks bad. For best
- results, make the camera location have greater x and z coordinates than the
- part of the graph you are observing. In polar mode, stay above the graph.
- * When you get too close to a 3D plot then the clipping of the edges can cause
- some distortion.
- * If the function is behind the camera, it will cause messy lines to appear.
- * You cannot customize the keys for graphics controls unless you edit the
- source code. Sorry, so many features, so little time.
- * 't' doesn't work in 3D mode, use 'T' instead.
- * The 256 color palette is reset each time you leave graphics mode (Esc or F1).
- To fix the palette you need to press 'x' again.
- * The COLOR BY SLOPE mode does not use ray tracing to find shadows. In this
- mode the lower half of the palette is shared by the "front" and the "back"
- of the function (use F5/F6 to control the sharing). If the light ?r has
- negative y value then the entire function may appear very dark.
-
- Note: If your graph gets all messed up and you can't fix it, try pressing 'd'.
-
- End of help text. Press any key to return.