## this is not a function file (-*- octave -*-)
## Dirk Bonne
1;

## the basic flevo parameters
## - all distances are in mm
## - angels are in radians
global flevo;

## radius of the front wheel (26'')
## 315 for 26'' (Hutchinson Top Slick Basic 26 x 1,2 oder Continental Sportcontact 26x1,3) 
## 235 for 20'' (Monte Carlo)
flevo.rf = 315;
#flevo.rf = 235;

## height of the seat
flevo.seatz = 300; #flevo.rf;

## distance from the contact point of the backwheel to the contact
## point of the front wheel when steering strait
flevo.lwb = 1300;

## how much the wheel axe is moved from the steering axis in Y direction
flevo.ldf = 0;
 
## the angel of the steering axis against Y direction
flevo.aa = 70 * pi / 180;
 
## angel of steering around vector vs where 0 is when steering strait
flevo.ab = 0;

## tilting angel of the back part around the Y axis in relation to Z axis 
flevo.aj = 0;

## calculated by flevo_calc values) defines the position of
## the front wheel with the formula: transf + rotf*[0; rf*cos(t);
## rf*sin(t)]
flevo.transf = [0;0;0];
flevo.rotf = eye(3);
## how to calculate the back part of the bicycle. Any point of the
## bicylce in the back part corresponds to transb + rotb*[x,y,z] where
## x,y,z is mesured from the contact point of the back wheel
flevo.transb = [0;0;0];
flevo.rotb = eye(3);

flevo_base;

flevo_calc;

function plot_change_height_vs_trail
  global flevo;

  grid on;
  
  ntrail = 50;
  trail_space = linspace(-300, 100, ntrail);
  naa = 6;
  aa_space = [30*pi/180; 45*pi/190; 55*pi/180; 70*pi/180; 80*pi/180; 90*pi/180];
  ##linspace(30*pi/180, 90*pi/180, naa);
  ## angle at which the wheel is turned:
  flevo.ab = 20 * pi/180;
  
  ## I set the y position of the seatheight intesects with the steering angle.

  gset title "seat height vs trail for different pivot angles (turning angle is 20degrees)";
  gset xlabel "trail (mm)";
  gset ylabel "seat height (mm)";
  for i = 1:naa
    flevo.aa = aa_space(i);
    for j = 1:ntrail
      ##    printf("RUN FOR TRAIL=%f\n", trail_space(j));
      flevo_set_trail(trail_space(j));
      flevo_calc();
      ## rotation around the back wheel axis
      seat = [0; flevo.lwb - flevo.ldf - (flevo.seatz - flevo.rf) / tan(flevo.aa); flevo.seatz];
      height(j) = flevo_bpoint(seat)(3);
    endfor;
    key = sprintf("-;angle=%.0f degrees;", flevo.aa*180/pi);
    plot(trail_space, height, key);
    hold on;
  endfor;
  hold off;

endfunction;

function plot_change_height_vs_aa
  global flevo;

  grid on;
  ntrail = 5;
  trail_space = linspace(-300, 100, ntrail);
  naa = 100;
  aa_space = linspace(30, 90, naa);
  ## angle at which the wheel is turned:
  flevo.ab = 20 * pi/180;
  
  ## I set the y position of the seatheight intesects with the steering angle.

  gset title "seat height vs pivot angle for some trails (turning angle is 20degrees)";
  gset xlabel "pivot angle (degrees)";
  gset ylabel "seat height (mm)";
  for j = 1:ntrail
    for i = 1:naa
      flevo.aa = (pi/180) * aa_space(i);
      ##    printf("RUN FOR TRAIL=%f\n", trail_space(j));
      flevo_set_trail(trail_space(j));
      flevo_calc();
      ## rotation around the back wheel axis
      seat = [0; flevo.lwb - flevo.ldf - (flevo.seatz - flevo.rf) / tan(flevo.aa); flevo.seatz];
      height(i) = flevo_bpoint(seat)(3);
    endfor;
    key = sprintf("-;trail=%.0f;", trail_space(j));
    plot(aa_space, height, key);
    hold on;
  endfor;
  hold off;

endfunction;

function plot_change_height_vs_ab
  global flevo;

  grid on;
  ntrail = 5;
  trail_space = linspace(-300, 100, ntrail);
  nab = 100;
  ab_space = linspace(0, 90, nab);
  ## angle at which the wheel is turned:
  flevo.aa = 55 * pi/180;
  
  ## I set the y position of the seatheight intesects with the steering angle.

  gset title "seat height vs turning angle for some trails (pivot angle is 55degrees)";
  gset xlabel "turning angle (degrees)";
  gset ylabel "seat height (mm)";
  for j = 1:ntrail
    for i = 1:nab
      flevo.ab = (pi/180) * ab_space(i);
      ##    printf("RUN FOR TRAIL=%f\n", trail_space(j));
      flevo_set_trail(trail_space(j));
      flevo_calc();
      ## rotation around the back wheel axis
      seat = [0; flevo.lwb - flevo.ldf - (flevo.seatz - flevo.rf) / tan(flevo.aa); flevo.seatz];
      height(i) = flevo_bpoint(seat)(3);
    endfor;
    key = sprintf("-;trail=%.0f;", trail_space(j));
    plot(ab_space, height, key);
    hold on;
  endfor;
  hold off;
endfunction;

#gset output "height_vs_trail.png";
#grid on;
#plot_change_height_vs_trail;

#  gset terminal png;
#  gset output "height_vs_aa.png";