Aiming - Revision history

Lerc at 20:53, 27 June 2017

2017-06-27T20:53:02Z

Lerc at 20:33, 27 June 2017

2017-06-27T20:33:39Z

Lerc at 20:12, 27 June 2017

2017-06-27T20:12:51Z

Lerc: Created page with " var t=0.0; var speed=0.02; var ax=100; var ay=320; var bx=400; var by=200; var annotation = ""; var dataNote = ""; var dataNote2 = ""; function loop() { if (t>=..."

2017-06-27T09:53:26Z

Created page with "<edcode> var t=0.0; var speed=0.02; var ax=100; var ay=320; var bx=400; var by=200; var annotation = ""; var dataNote = ""; var dataNote2 = ""; function loop() { if (t>=..."

New page

<edcode>

var t=0.0;
var speed=0.02;
var ax=100;
var ay=320;

var bx=400;
var by=200;

var annotation = "";
var dataNote = "";
var dataNote2 = "";

function loop() {
if (t>=1) t=0;
}

function setDefaults() {
ax=100;
ay=320;
bx=400;
by=200;
speed=0.02;
annotation = "";
dataNote = "";
dataNote2 = "";
}

function ss(v,a,b) {
var w=v*v*v*(v*(v*6-15)+10);
return(1.0-w)*a+(w*b);
}

function transition(a,b) {
return ss(t,a,b);
}

function wiggle(a,b) {

var w=t*2;
if (w>1) w=2-w;
return ss(w,a,b);
}

function spots() {
setColour("red");
fillCircle(ax,ay,7);
setColour("purple");
fillCircle(bx,by,7);

annotation="We want to move the red point towards the purple point";
}

function hvLines() {
spots();
setColour("blue");
drawLine(ax,ay,bx,ay);
setColour("green");
drawLine(ax,ay,ax,by);

annotation="We know the difference in x and y values for the two points";

}

function hvLines_transition() {
spots();
setColour("blue");
drawLine(ax,ay,bx,ay);
setColour("green");

annotation="Combining the lines makes a path from one to the other";

drawLine(transition(ax,bx),ay,transition(ax,bx),by);
}

function pale_hvLines() {
spots();
setColour("lightblue");
drawLine(ax,ay,bx,ay);
setColour("lightgreen");
drawLine(bx,ay,bx,by);
setColour("magenta");
drawLine(ax,ay,bx,by);
}

function triangleNote() {
var dx= bx-ax;
var dy= by-ay;
var d = Math.sqrt(dx*dx+dy*dy);

dataNote = "Distance from ax,ay to bx,by is " +d.toFixed(1);
}

function triangle() {
spots();
setColour("blue");
drawLine(ax,ay,bx,ay);
setColour("green");
drawLine(bx,ay,bx,by);
setColour("magenta");
drawLine(ax,ay,bx,by);

annotation="Adding the straight line to the target makes a right angled triangle";

triangleNote();
}

function vector(newLength) {
var dx= bx-ax;
var dy= by-ay;
var d = Math.sqrt(dx*dx+dy*dy);

dx/=d;
dy/=d;
setColour("black");
drawLine(ax,ay-1,ax+dx*newLength,ay-1+dy*newLength);
drawLine(ax,ay+1,ax+dx*newLength,ay+1+dy*newLength);

}

function vector_transition() {
triangle();
vector(transition(0,30));
annotation="We want to move a fixed distance along this line";
dataNote+=", we want to move a distance of 30";
}

function move_around() {
bx=wiggle(bx,40);
by=wiggle(by,300);
ax=wiggle(ax,ax+30);
ay=wiggle(ay,ay+30);
triangle();
vector(30);
speed=0.003;
loop();
annotation="When the points are different the distance should stay the same";
dataNote+=", we want to move a distance of 30";
}

function stopped() {
triangle();
vector(30);
annotation="To find x and y movement we reduce both values by the same amount";
dataNote+=", we want to move a distance of 30";
}

function show_parts() {
pale_hvLines();

vector(30);

setColour("blue");

var dx= bx-ax;
var dy= by-ay;
var d = Math.sqrt(dx*dx+dy*dy);
dx/=d;
dy/=d;
var scale = transition(d,30);

drawLine(ax,ay,ax+dx*scale,ay);
setColour("green");
drawLine(ax+dx*scale,ay,ax+dx*scale,ay+dy*scale);

speed=0.001;

annotation="The angles stay the same if the sides are divided by the same amount";
triangleNote();
dataNote+=", we want to move a distance of 30";

var newdx=dx*scale;
var newdy=dy*scale;
var newd = Math.sqrt(newdx*newdx+newdy*newdy);
var div = d/newd*30;
dataNote2=" "+d.toFixed(1)+ " / " +div.toFixed(1) +" * 30 = " +(newd).toFixed(1);
}

var parts=[spots, hvLines, hvLines_transition,triangle,vector_transition,move_around,stopped,show_parts];
var part=0;

function update() {
setDefaults();
clear();
parts[part]();

setColour("black");
print(annotation);

setColour("grey");
print("ax = "+ax.toFixed(0)+" bx = "+bx.toFixed(0)+" dx = bx-ax = " + (bx-ax).toFixed(0) ,100,370);
print("ay = "+ay.toFixed(0)+" by = "+by.toFixed(0)+" dy = by-ay = " + (bx-ax).toFixed(0) ,100,400);
print(dataNote,4,430);
print(dataNote2,4,460);

t+=speed;
if (t>1) {
t=1;
}

if (keyWentDown(32)) {
t=0;
part+=1;
if (part>=parts.length) {
part =0;
}
}

}

run(update);
</edcode>

@@ Line 210: / Line 210: @@
    if (part+1<parts.length ) {
       setColour("black");
-      print("Pres Space to continue.",220,470);
+      print("Press Space to continue.",220,470);
+   }

@@ Line 3: / Line 3: @@
 <edcode>
 var t=0.0;
 var speed=0.02;
@@ Line 104: / Line 105: @@
    drawLine(ax,ay,bx,by);
-   annotation="Adding the straight line to the target makes a right angled triangle";
+   annotation="The straight line to the target makes a right angled triangle";
    triangleNote();
@@ Line 128: / Line 129: @@
    vector(transition(0,30));
    annotation="We want to move a fixed distance along this line";
-   dataNote+=", we want to move a distance of 30";
+   dataNote+=". We want to move 30";
+}
@@ Line 140: / Line 141: @@
    speed=0.003;
    loop();
-   annotation="When the points are different the move distance should stay the same";
+   annotation="The movement distance should always be the same ";
-   dataNote+=", the move distance we want is 30";
+   dataNote+=". We want to move 30 ";
+}
@@ Line 147: / Line 148: @@
    triangle();
    vector(30);
-   annotation="To find x and y movement we reduce both values by the same amount";
+   annotation="To find our movement we scale all values by the same amount";
-   dataNote+=", the move distance we want is 30";
+   dataNote+=". We want to move 30";
+}
@@ Line 171: / Line 172: @@
    speed=0.001;
-   annotation="The angles stay the same if the sides are divided by the same amount";
+   annotation="The angles stay the same when all sides are scaled evenly";
    triangleNote();
-   dataNote+=", the move distance we want is 30";
+   dataNote+=". We want to move 30";
    var newdx=dx*scale;
@@ Line 230: / Line 231: @@
 run(update);
 </edcode>

@@ Line 1: / Line 1: @@
-<edcode>
+Run this program to see an animated diagram shoing how to find a direction towards another point.
 var t=0.0;
 var speed=0.02;
@@ Line 138: / Line 140: @@
    speed=0.003;
    loop();
-   annotation="When the points are different the distance should stay the same";
+   annotation="When the points are different the move distance should stay the same";
-   dataNote+=", we want to move a distance of 30";
+   dataNote+=", the move distance we want is 30";
+}
@@ Line 146: / Line 148: @@
    vector(30);
    annotation="To find x and y movement we reduce both values by the same amount";
-   dataNote+=", we want to move a distance of 30";
+   dataNote+=", the move distance we want is 30";
+}
@@ Line 171: / Line 173: @@
    annotation="The angles stay the same if the sides are divided by the same amount";
    triangleNote();
-   dataNote+=", we want to move a distance of 30";
+   dataNote+=", the move distance we want is 30";
    var newdx=dx*scale;
@@ Line 177: / Line 179: @@
    var newd = Math.sqrt(newdx*newdx+newdy*newdy);
    var div = d/newd*30;
-   dataNote2=" "+d.toFixed(1)+ " / " +div.toFixed(1) +" * 30 = "  +(newd).toFixed(1);
+}
@@ Line 190: / Line 199: @@
    setColour("black");
-   print(annotation);
+   print(annotation,4,22);
    setColour("grey");
    print("ax = "+ax.toFixed(0)+"     bx = "+bx.toFixed(0)+"            dx = bx-ax = " + (bx-ax).toFixed(0) ,100,370);
-   print("ay = "+ay.toFixed(0)+"     by = "+by.toFixed(0)+"            dy = by-ay = " + (bx-ax).toFixed(0) ,100,400);
+   print("ay = "+ay.toFixed(0)+"     by = "+by.toFixed(0)+"            dy = by-ay = " + (by-ay).toFixed(0) ,100,400);
    print(dataNote,4,430);
    print(dataNote2,4,460);
-−
    t+=speed;
    if (t>1) {
@@ Line 216: / Line 230: @@
 run(update);
 </edcode>