## Saturday, December 3, 2016

### TI-84 Plus: Rake Wall

TI-84 Plus:  Rake Wall

The program RAKEWALL calculates:

*  The positions and lengths of studs on a rake wall
*  Angle of the incline

I wanted to do something different and present an illustration rather than just text answers.  What is nice of the TI-84 Plus (and really the TI-8x family extending back to the TI-81) is that the programming language allowing for easy transition between modes (home, graphing, matrix editing, table, etc.).  With RAKEWALL, I not only display text answers, but a visual of how the rake wall is laid out.

Sometimes the best way to present information is through visuals, not just text.  I want to further explore this whenever it is warranted.

TI-84 Plus Program RAKEWALL

Input:  Rise, Run, O.C. (on center spacing).   RAKEWALL does not specify units, keep that in mind.  Use consistent units.  As a reminder, 12 inches is 1 foot.

Output:  Angle (in Degrees), stud spacing stored in list L1, stud lengths stored in list L2.  The program ends on the graph screen.  Press [ trace ] to see the values.  X is the length from the where the incline and base meet to the stud, Y is the stud length.

Please note that results are exact and not rounded (i.e. to the nearest 1/16th).

Program:
"EWS 2016-12-01"
ClrDraw
Degree
Input "RUN:",L
Input "O.C. SPACING:",S
Input "BASE:",B
Input "RISE:",R

seq(X,X,L,0,­-S)→L1
tan^-1(R/L)→θ

L1*tan(θ)+B→L2
augment(L1,{0})→L1
augment(L2,{B})→L2

Disp "ANGLE:",θ
Disp "NUMBER OF STUDS:",dim(L1)-2
Disp "(L1: DIST. FROM SHORT PT."
Disp "L2: STUD LENGTH)"
Pause

PlotsOff
PlotsOn 1
Plot1(xyLine,L1,L2)

­0.5→Ymin
B+R+.5→Ymax
­.5→Xmin
L+.5→Xmax

For(I,1,dim(L1))
Line(L1(I),0,L1(I),L2(I))
End
Line(0,0,L,0)
Line(L,0,L,B)

DispGraph

Example:

Run:  6 feet
O.C.:  1 foot 6 inches, or 16/12 inches
Base:  6 feet
Rise:  5 feet

This program was inspired by the Calculated Industries Construction Master 5 calculator.  I am thinking about purchasing their Construction Pro calculator (most likely the app).

Happy December!

Eddie

This blog is property of Edward Shore, 2016.