Slope Field Creator

[Xeda112358]

Hey y'all, try this:

a+bi
ClrHome
Input "EQU:",Str1
Str1→u
ClrHome
3ΔX→B Change this to something like 5ΔX if you want.
3ΔY→C
For(X,Xmin-1.5B,Xmax+.5B,2B
For(Y,Ymin-1.5C,Ymax+.5C,2C
If not(imag(u
Line(X,Y,X+B,Y+Cu
End
End

ΔX and ΔY are very useful because they can control the window range, too. These hold the ratio of total window range:#of pixels. 1→ΔY would mean that every time you move the cursor down or up, the Y value decrements or increments 1. Likewise, you can get the current value by using these.

[thornahawk]

The code in ThunderBolt's post is correct only if you have set ΔY==ΔX; the slope of the lines generated are incorrect otherwise.

thornahawk

[Xeda112358]

Visually, yes, but mathematically, no. If you're window range is skewed, the graph of the actual equation will look skewed, too. So really, it isn't the slope that is wrong, it is the graph.

[thornahawk]

The slope of Line(X,Y,X+B,Y+Cu) == Line(X,Y,X+3ΔX,Y+3ΔYu) is (Y+3ΔYu-Y)/(X+3ΔX-X) == ΔYu/ΔX when it should be just plain u. :|

thornahawk

[meishe91]

I'm not really following any of that.

[Xeda112358]

Gotcha, my bad.